AU2012201521A1 - Modified clostridial toxins with enhanced targeting capabilites for endogenous clostridial toxin receptor systems - Google Patents

Abstract

C \NRPortbl\DCOGRS\429324_I.DOC-14/3/2012 MODIFIED CLOSTRIDIAL TOXINS WITH ENHANCED TARGE4TING CAPABILITIES FOR ENDOGENOUS CLOSTRIDIAL TOXIN RECEPTOR SYSTGEMS The specification discloses modified Clostridial toxins comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced Clostridial toxin binding domain; polynucleotide molecules encoding such modified Clostridial toxins; and method of producing such modified Clostridial toxins.

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Modified clostridial toxins with enhanced targeting capabilities for endogenous clostridial toxin receptor systems The following statement is a full description of this invention, including the best method of performing it known to me: P/00/ol 5951 WO 2006/101809 PCT/US2006/008956 Modified Clostridial Toxins with Enhanced Targeting Capabilities For Endogenous Clostridial Toxin Receptor Systems [01] This patent application claims priority pursuant to 35 U.S.C. §119(e) to United States provisional patent application Serial No. 60/662,151 filed on March 15, 2005 and United States provisional patent application Serial No. 60/661,953 filed on March 15, 2005, both of which are hereby incorporated by reference in their entirety. (02] All of the patents and publications cited in this application are hereby incorporated by reference in their entirety. [03] The ability of Clostridial toxins, such as, e.g., Botullnum neurotoxins (BoNTs), BoNT/A, BoNT/B, BoNT/C1, BoNT/D, BoNT/E, BoNT/F and BoNT/G, and Tetanus neurotoxin (TeNT), to inhibit neuronal transmission are being exploited in a wide variety of therapeutic and cosmetic applications, see e.g., William J. Lipham, CosMEnC AND CLINICAL APPLICATIONS OF BOTULINUM TOXIN (Slack, Inc., 2004). As an example, BOTOX is currently approved in one or more countries for the following indications: achalasia, adult spasticity, anal fissure, back pain, blepharospasm, bruxism, cervical dystonia, essential tremor, glabellar lines or hyperkinetic facial lines, headache, hemifacial spasm, hyperactivity of bladder, hyperhidrosis, juvenile cerebral palsy, multiple sclerosis, myoclonic disorders, nasal labial lines, spasmodic dysphonia, strabismus and VII nerve disorder. in addition, Clostridial toxin therapies are proposed for treating neuromuscular disorders, see e.g., Kei Roger Aoki et al., Method for Treating Neuromuscular Disorders and Conditions with Botulinum Toxin Types A and B, U.S. Patent No. 6,872,397 (Mar. 29, 2005); Rhett M. Schiffman, Methods for Treating Uterine Disorders, U.S. Patent Publication No. 2004/0175399 (Sep. 9, 2004); Richard L. Barron, Methods for Treating Ulcers and Gastroesophageai Reflux Disease, U.S. Patent Publication No. 2004/0086531 (May. 7, 2004); and Kei Roger Aoki, et al., Method for Treating Dystonia with Botulinum Toxin C to G, U.S. Patent No. 6,319,505 (Nov. 20, 2001); eye disorders, see e.g., Eric R. First, Methods and Compositions for Treating Eye Disorders, U.S. Patent Publication No. 2004/0234532 (Nov. 25, 2004); Kel Roger Aoki et al., Botulinum Toxin Treatment for Blepharospasm, U.S. Patent Publication No. 2004/0151740 (Aug. 5, 2004); and Kei Roger Aoki et al., Botulinum Toxin Treatment for Strabismus, U.S. Patent Publication No. 2004/0126396 (Jul. 1, 2004); pain, see e.g., Kei Roger Aoki et al., Pain Treatment by Peripheral Administration of a Neurotoxin, U.S. Patent No. 6,869,610 (Mar. 22, 2005); Stephen Donovan, Ciostridial Toxin Derivatives and Methods to Treat Pain, U.S. Patent No. 6,641,820 (Nov. 4, 2003); Kei Roger Aoki, et al., Method for Treating Pain by Peripheral Administration of a Neurotoxin, U.S. Patent No. 6,464,986 (Oct 15, 2002); Kei Roger Aoki and Minglei Cul, Methods for Treating Pain, U.S. Patent No. 6,113,915 (Sep. 5, 2000); Martin A. Voet, Methods for Treating Fibromyalgia, U.S. Patent 6,623,742 (Sep. 23, 2003); Martin A. Voet, Botulinum Toxin Therapy for Fibromyalgia, U.S. Patent Publication No. 2004/0062776 (Apr. 1, 2004); and Kel Roger Aoki et al., Botulinum Toxin Therapy for Lower Back Pain, U.S. Patent Publication 1 of 316 WO 2006/101809 PCT/US2006/008956 No. 2004/0037852 (Feb. 26, 2004); muscle injuries, see e.g., Gregory F. Brooks, Methods for Treating Muscle Injuries, U.S. Patent No. 6,423,319 (Jul. 23, 2002); headache, see e.g., Martin Voet, Methods for Treating Sinus Headache, U.S. Patent No. 6,838,434 (Jan. 4, 2005); Kei Roger Aoki et al., Methods for Treating Tension Headache, U.S. Patent No. 6,776,992 (Aug. 17, 2004); and Kei Roger Aoki et al., Method for Treating Headache, U.S. Patent No. 6,458,365 (Oct. 1, 2002); William J. Binder, Method for Reduction of Migraine Headache Pain, U.S. Patent 5,714,469 (Feb. 3, 1998); cardiovascular diseases, see e.g., Gregory F. Brooks and Stephen Donovan, Methods for Treating Cardiovascular Diseases with Botulinum Toxin, U.S. Patent No. 6,767,544 (Jul. 27, 2004); neurological disorders, see e.g., Stephen Donovan, Parkinson's Disease Treatment, U.S. Patent No. 6,620,415 (Sep. 16, 2003); and Stephen Donovan, Method for Treating Parkinson's Disease with a Botufinum Toxin, U.S. Patent No. 6,306,403 (Oct. 23, 2001); neuropsychiatric disorders, see e.g., Stephen Donovan, Botullnum Toxin Therapy for Neuropsychiatric Disorders, U.S. Patent Publication No. 2004/0180061 (Sep. 16, 2004); and Steven Donovan, Therapeutic Treatments for Neuropsychiatric Disorders, U.S. Patent Publication No. 2003/0211121 (Nov. 13, 2003); endocrine disorders, see e.g., Stephen Donovan, Method for Treating Endocrine Disorders, U.S. Patent No. 6,827,931 (Dec. 7, 2004); Stephen Donovan, Method for Treating Thyroid Disorders with a Botulinum Toxin, U.S. Patent No. 6740321 (May. 25, 2004); Kei Roger Aoki et al., Method for Treating a Cholinergic influenced Sweat Gland, U.S. Patent No. 6,683,049 (Jan. 27, 2004); Stephen Donovan, Neurotoxin Therapy for Diabetes, U.S. Patent No. 6,416,765 (Jul. 9, 2002); Stephen Donovan, Methods for Treating Diabetes, U.S. Patent No. 6,337,075 (Jan. 8, 2002); Stephen Donovan, Method for Treating a Pancreatic Disorder with a Neurotoxin, U.S. Patent No. 6,261,572 (Jul. 17, 2001); Stephen Donovan, Methods for Treating Pancreatic Disorders, U.S. Patent No. 6,143,306 (Nov. 7, 2000); cancers, see e.g., Stephen Donovan, Methods for Treating Bone Tumors, U.S. Patent No. 6,565,870 (May 20, 2003); Stephen Donovan, Method for Treating Cancer with a Neurotoxin to Improve Patient Function, U.S. Patent No. 6,368,605 (Apr. 9, 2002); Stephen Donovan, Method for Treating Cancer with a Neurotoxin, U.S. Patent No. 6,139,845 (Oct. 31, 2000); and Mitchell F. Brin and Stephen Donovan, Methods for Treating Diverse Cancers, U.S. Patent Publication No. 2005/0031648 (Feb. 10, 2005); otic disorders, see e.g., Stephen Donovan, Neurotoxin Therapy for inner Ear Disorders, U.S. Patent No. 6358926 (Mar. 19, 2002); and Stephen Donovan, Method for Treating Otic Disorders, U.S. Patent No. 6265379 (Jul. 24, 2001); autonomic disorders, see, e.g., Pankal J. Pasrlcha and Anthony N. Kalloo, Method for Treating Gastrointestinal Muscle Disorders and Other Smooth Muscle Dysfunction, U.S. Patent 5,437,291 (Aug. 1, 1995); as well as other disorders, see e.g., William J. Binder, Method for Treatment of Skin Lesions Associated with Cutaneous Cell-proliferative Disorders, U.S. Patent 5,670,484 (Sep. 23, 1997); Eric R. First, Application of Botulinum Toxin to the Management of Neurogenic Inflammatory Disorders, U.S. Patent 6,063,768 (May 16, 2000); Marvin Schwartz and Brian J. Freund, Method to Reduce Hair Loss and Stimulate Hair Growth, U.S. Patent 6,299,893 (Oct. 9, 2001); Jean D. A. Carruthers and Alastair Carruthers, Cosmetic Use of Botulinum Toxin for Treatment of Downtumed Mouth, U.S. Patent 6,358,917 (Mar. 19, 2002); Stephen Donovan, Use of a Clostridial Toxin to Reduce Appetite, U.S. Patent Publication No. 2004/40253274 (Dec. 16, 2004); and Howard I. Katz and Andrew M. Blumenfeld, Botulinum Toxin Dental Therapies and Procedures, U.S. Patent Publication No. 2 of 316 WO 2006/101809 PCT/US2006/008956 2004/0115139 (Jun. 17, 2004); Kei Roger Aoki, et al., Treatment of Neuromuscular Disorders and Conditions with Different Botulinum, U.S. Patent Publication No. 2002/0010138 (Jan. 24, 2002); and Kei Roger Aoki, et al., Use of Botulinum Toxins for Treating Various Disorders and Conditions and Associated Pain, U.S. Patent Publication No. 2004/0013692 (Jan. 22, 2004). In addition, the expected use of Clostridial toxins, such as, e.g., BoNTs and TeNT, in therapeutic and cosmetic treatments of humans and other mammals Is anticipated to expand to an ever widening range of diseases and ailments that can benefit from the properties of these toxins. [04] Clostridial toxin therapies are successfully used for many indications. Generally, administration of a Clostridlal toxin treatment is well tolerated. However, toxin administration in some applications can be challenging because of the larger doses required to achieve a beneficial effect. Larger doses can increase the likelihood that the toxin may move through the interstitial fluids and the circulatory systems, such as, e.g., the cardiovascular system and the lymphatic system, of the body, resulting in the undesirable dispersal of the toxin to areas not targeted for toxin treatment. Such dispersal can lead to undesirable side effects, such as, e.g., inhibition of neurotransmitter release in neurons not targeted for treatment or paralysis of a muscle not targeted for treatment. For example, a patient administered a therapeutically effective amount of a BoNT/A treatment into the neck muscles for torticollis may develop dysphagia because of dispersal of the toxin into the oropharynx. Thus, there remains a need for improved Clostridial toxins that are effective at the site of treatment, but have negligible to minimal effects in areas not targeted for a toxin treatment. [05] The growing clinical, therapeutic and cosmetic use of Clostridial toxins in therapies requiring larger doses necessitates the pharmaceutical industry to develop modified Clostridial toxins that are effective at the target site of the application, but reduce or prevent the undesirable side-effects associated with the dispersal of the toxins to an unwanted location or locations. The present invention provides novel Clostridial toxins that reduce or prevent unwanted side-effects associated with toxin dispersal into non targeted areas. These and related advantages are useful for various clinical, therapeutic and cosmetic applications, such as, e.g., the treatment of neuromuscular disorders, neuropathic disorders, eye disorders, pain, muscle injuries, headache, cardiovascular diseases, neuropsychiatric disorders, endocrine disorders, cancers, otic disorders and hyperkinetic facial lines, as well as, other disorders where a Clostridial toxin administration to a mammal can produce a beneficial effect. BRIEF DESCRIPTION OF THE DRAWINGS [06] FIG. 1 shows a schematic of the current paradigm of neurotransmitter release and Clostridial toxin intoxication in a central and peripheral neuron. FIG. 1A shows a schematic for the neurotransmitter release mechanism of a central and peripheral neuron. The release process can be described as comprising two steps: 1) vesicle docking, where the vesicle-bound SNARE protein of a vesicle containing neurotransmitter molecules associates with the membrane-bound SNARE proteins located at the plasma 3 of 316 WO 2006/101809 PCT/US2006/008956 membrane; and 2) neurotransmitter release, where the vesicle fuses with the plasma membrane and the neurotransmitter molecules are exocytosed. FIG. 1 B shows a schematic of the Intoxication mechanism for tetanus and botulinum toxin activity in a central and peripheral neuron. This intoxication process can be described as comprising four steps: 1) receptor binding, where a Clostridial toxin binds to a Clostridial receptor system and initiates the intoxication process; 2) complex internalization, where after toxin binding, a vesicle containing the toxin/receptor system complex is endocytosed Into the cell; 3) light chain translocation, where multiple events are thought to occur, including, e.g., changes in the internal pH of the vesicle, formation of a channel pore comprising the HN domain of the Clostridial toxin heavy chain, separation of the Clostridial toxin light chain from the heavy chain, and release of the active light chain and 4) enzymatic target modification, where the activate light chain of Clostridial toxin proteolytically cleaves its target SNARE substrate, such as, e.g., SNAP-25, VAMP or Syntaxin, thereby preventing vesicle docking and neurotransmitter release. [07] FIG. 2 shows the domain organization of naturally-occurring Clostridial toxins. The single chain form depicts the amino to carboxyl linear organization comprising an an enzymatic domain, a translocation domain, and a binding domain. The di-chain loop region located between the translocation and enzymatic domains is depicted by the double SS bracket. This region comprises an endogenous di-chain loop protease cleavage site that upon proteolytic cleavage with a naturally-occurring protease, such as, e.g., an endogenous Clostridial toxin protease or a naturally-occurring protease produced in the environment, converts the single chain form of the toxin into the di-chain form. Above the single-chain form, the Hcc region of the Clostridial toxin binding domain is depicted. This region comprises the 3 trefoil domain which comprises in a amino to carboxyl linear organization an a-fold, a 04/05 hairpin turn, a 0-fold, a 08/09 hairpin turn and a y-fold. [08] FIG. 3 shows modified Clostridial toxins with an enhanced targeting domain located at the amino terminus of the modified toxin. FIG. 3A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enhanced targeting domain, an enzymatic domain and a translocation domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation and enzymatic domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the targeting and translocation domains, the translocation and enzymatic domains or any combination thereof. FIG. 3B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enhanced targeting domain, an enzymatic domain and a translocation domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the enzymatic and translocation domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease 4 of 316 WO 2006/101809 PCT/US2006/008956 cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the targeting and enzymatic domains, the enzymatic and translocation domains or any combination thereof. [09]FIG. 4 shows modified Clostridial toxins with an enhanced targeting domain located between the other two domains. FIG. 4A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enzymatic domain, an enhanced targeting domain and a translocation domain, with the di-chain loop region depicted by the double SS bracket A proteolytic cleavage site (P) within a di-chain loop region is located between the enzymatic and targeting domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the enzymatic and targeting domains, the targeting and translocation domains or any combination thereof. FIG. 4B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation domain, an enhanced targeting domain and an enzymatic domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation and targeting domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the translocation and targeting domains, the targeting and enzymatic domains or any combination thereof. [0101 FIG. 5 shows modified Clostridial toxins with an enhanced targeting domain located at the carboxyl terminus of the modified toxin. FIG. 5A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enzymatic domain, a translocation domain and an enhanced targeting domain, with the di-chain loop region depicted by the double SS bracket. A proteolytlc cleavage site (P) within a di-chain loop region is located between the enzymatic and translocation domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the enzymatic and translocation domains, the translocation and targeting domains or any combination thereof. FIG. 5B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation domain, an enzymatic domain and an enhanced targeting domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation and enzymatic domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed 5 of 316 WO 2006/101809 PCT/US2006/008956 between the translocation and enzymatic domains, the enzymatic and targeting domains or any combination thereof. DETAILED DESCRIPTION [011] The present invention discloses modified Clostridial toxins that exhibit enhanced binding activity for cells targeted by naturally-occurring Clostridial toxins. Enhanced binding activity is achieved by replacing a naturally-occurring binding domain of a Clostridial toxin with a binding domain showing enhanced binding activity for a Clostridial toxin target cell. This enhanced binding activity for a target cell should allow lower effective doses of a modified Clostridial toxin to be administered to an individual because more toxin will be delivered to a target cell. Thus modified Clostridial toxins with enhanced binding activity will reduce the undesirable dispersal of the toxin to areas not targeted for treatment, thereby reducing or preventing the undesirable side-effects associated with diffusion of a Clostridial toxin to an unwanted location. [012] Aspects of the present invention provide modified Clostridlal toxins comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain, wherein the modified Clostridial toxin exhibits an enhanced targeting activity for a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. It is envisioned that the location of the enhanced targeting domain in the modified Clostridial toxins of the present specification can be located at the amino terminus of the toxin, between the enzymatic and translocation domains or at the carboxyl terminus of the toxin. Thus, a modified Clostridial toxins disclosed in the present specification can comprise an amino to carboxyl domain arrangement of, e.g., an enhanced targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin enzymatic domain; an enhanced targeting domain, a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain; a Clostridial toxin enzymatic domain, an enhanced targeting domain and a Clostridial toxin translocation domain; a Clostridial toxin translocation domain, an enhanced targeting domain and a Clostridial toxin enzymatic domain; a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain; and a Clostridial toxin translocation domain, a Clostridial toxin enzymatic domain and an enhanced targeting domain. [013] Other aspects of the present invention provide polynucleotide molecules encoding modified Clostridial toxins comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain, wherein the modified Clostridial toxin exhibits an enhanced targeting activity for a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. It is envisioned that the location of the enhanced targeting domain of the modified Clostridial toxins encoded by polynucleotide molecules of the present specification can be located at the amino terminus of the toxin, between the enzymatic and translocation domains or at the carboxyl terminus of the toxin. Thus, polynucleotide molecules disclosed in the present specification can encoded modified Clostridial toxins 6 of 316 WO 2006/101809 PCT/US2006/008956 comprising an amino to carboxyl domain arrangement of, e.g., an enhanced targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin enzymatic domain; an enhanced targeting domain, a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain; a Clostridial toxin enzymatic domain, an enhanced targeting domain and a Clostridial toxin translocation domain; a Clostridial toxin translocation domain, an enhanced targeting domain and a Clostridial toxin enzymatic domain; a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain; and a Clostridial toxin translocation domain, a Clostridial toxin enzymatic domain and an enhanced targeting domain. [014] Other aspects of the present Invention provide methods of producing a modified Clostridial toxin disclosed in the present specification, the method comprising the step of expressing in a cell a polynucleotide molecule encoding a modified Clostridial toxin comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain, wherein the modified Clostridial toxin exhibits an enhanced targeting activity for a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. Other aspects of the present Invention provide methods of producing a modified Clostridial toxin disclosed in the present specification, the method comprising the steps of introducing in a cell an expression construct comprising a polynucleotide molecule encoding a modified Clostridial toxin comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain, wherein the modified Clostridial toxin exhibits an enhanced targeting activity for a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin and expressing the expression construct in the cell. [015] Clostridia toxins produced by Clostridium botulinum, Clostidium tetani, Clostridium baratl and Clostridium butyricum are the most widely used in therapeutic and cosmetic treatments of humans and other mammals. Strains of C. botulinum produce seven antigenically-distinct types of Botulinum toxins (BoNTs), which have been identified by Investigating botulism outbreaks in man (BoNT/A, /B, /E and /F), animals (BoNT/C1 and /D), or isolated from soil (BoNT/G). While all seven botulinum toxins (BoNT) serotypes have similar structure and pharmacological properties, each also displays heterogeneous bacteriological characteristics. In contrast, tetanus toxin (TeNT) is produced by a uniform group of C. tetani. Two other species of Clostridia, C. baratil and C. butyricum, also produce toxins similar to BoNT/F and BoNT/E, respectively. [016] Clostridia toxins possess approximately 35% amino acid identity with each other and share the same functional domain organization and overall structural architecture. Clostridial toxins are each translated as a single chain polypeptide of approximately 150 kDa that is subsequently cleaved by proteolytic scission within a disulfide loop by a naturally-occurring protease, such as, e.g., an endogenous Clostridial toxin protease or a naturally-occurring protease produced in the environment (FIG. 2). This posttranslational processing yields a di-chain molecule comprising an approximately 50 kDa light chain (LC) and an approximately 100 kDa heavy chain (HC) held together by a single disulfide bond and 7 of 316 WO 2006/101809 PCT/US2006/008956 noncovalent interactions. Each mature di-chain molecule comprises three functionally distinct domains: 1) an enzymatic domain located in the LC that includes a metalloprotease region containing a zinc dependent endopeptidase activity which specifically targets core components of the neurotransmItter release apparatus (Table 1); 2) a translocation domain contained within the amino-terminal half of the HC (HN) that facilitates release of the LC from intracellular vesicles into the cytoplasm of the target cell (Table 1); and 3) a binding domain found within the carboxyl-terminal half of the HC (Hc) that determines the binding activity and binding specificity of the toxin to the receptor complex located at the surface of the target cell (Table 1). Table 1. Clostridial Toxin Reference Sequences and Regions Toxin SEQ ID NO: LC Hc BoNT/A 1 M1-K448 A449-K871 N872-L1296 BoNT/B 2 M1-K441 A442-S858 E859-E1291 BoNT/C1 3 M1-K449 T450-N866 N867-E1291 BoNT/D 4 M1-R445 D446-N862 S863-E1276 BoNT/E 5 M1 -R422 K423-K845 R846-K1252 BoNT/F 6 M1-K439 A440-K864 K865-E1274 BoNT/G 7 M1-K446 S447-S863 N864-E1297 TeNT 8 M1 -A457 S458-V879 1880-D1 315 [017] The binding, translocation and enzymatic activity of these three functional domains are all necessary for toxicity. While all details of this process are not yet precisely known, the overall cellular intoxication mechanism whereby Clostridial toxins enter a neuron and Inhibit neurotransmitter release is similar, regardless of serotype or subtype. Although the applicants have no wish to be limited by the following description, the intoxication mechanism can be described as comprising at least four steps: 1) receptor binding, 2) complex internalization, 3) light chain translocation, and 4) enzymatic target modification (see FIG. 1). The process Is initiated when the Hc domain of a Clostridial toxin binds to a toxin-specific receptor system located on the plasma membrane surface of a target cell. The binding specificity of a receptor complex is thought to be achieved, in part, by specific combinations of gangliosides and protein receptors that appear to distinctly comprise each Clostridial toxin receptor complex. Once bound, the toxin/receptor complexes are internalized by endocytosis and the internalized vesicles are sorted to specific intracellular routes. The translocation step appears to be triggered by the acidification of the vesicle compartment. This process seems to initiate two important pH-dependent structural rearrangements that increase hydrophobicity and promote formation di-chain form of the toxin. Once activated, light chain endopeptidase of the toxin is released from the intracellular vesicle Into the cytosol where it appears to specifically targets one of three known core components of the neurotransmitter release apparatus. These core proteins, vesicle-associated membrane protein (VAMP)/synaptobrevin, synaptosomal-associated protein of 25 kDa (SNAP-25) and Syntaxin, are 8 of 316 WO 2006/101809 PCT/US2006/008956 necessary for synaptic vesicle docking and fusion at the nerve terminal and constitute members of the soluble N-ethylmalelmide-sensitive factor-attachment protein-[gceptor (SNARE) family. BoNT/A and BoNT/E cleave SNAP-25 in the carboxyl-terminal region, releasing a nine or twenty-six amino acid segment, respectively, and BoNT/C1 also cleaves SNAP-25 near the carboxyl-terminus. The botulinum serotypes BoNT/B, BoNT/D, BoNT/F and BoNT/G, and tetanus toxin, act on the conserved central portion of VAMP, and release the amino-terminal portion of VAMP Into the cytosol. BoNT/C1 cleaves syntaxin at a single site near the cytosolic membrane surface. The selective proteolysis of synaptic SNAREs accounts for the block of neurotransmitter release caused by Clostridial toxins in vivo. The SNARE protein targets of Clostridial toxins are common to exocytosis in a variety of non-neuronal types; in these cells, as in neurons, light chain peptidase activity inhibits exocytosis, see, e.g., Yann Humeau et al., How Botulinum and Tetanus Neurotoxins Block Neurotransmitter Release, 82(5) Biochimie. 427-446 (2000); Kathryn Turton et al., Botulinum and Tetanus Neurotoxins: Structure, Function and Therapeutic Utility, 27(11) Trends Biochem. Sci. 552-558. (2002); Giovanna Lalli et al., The Joumey of Tetanus and Botulinum Neurotoxins in Neurons, 11(9) Trends Microblol. 431-437, (2003). [018] Aspects of the present invention provide, in part, a modified Clostridial toxin. As used herein, the term "modified Clostridial toxin" means any polypeptide that can execute the overall cellular mechanism whereby a Clostridial toxin enters a neuron and Inhibits neurotransmitter release and encompasses the binding of a Clostridial toxin to a low or high affinity receptor complex, the internalization of the toxin, the translocation of the Clostridial toxin light chain into the cytoplasm and the enzymatic modification of a Clostridial toxin substrate. A modified Clostridial toxin disclosed in the present specification is distinguished from a naturally-occurring Clostridial toxin by the fact that a modified Clostridial toxin lacks the cell binding activity of a naturally-occurring binding domain found in a Clostridial toxin. Instead, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain that determines the binding activity of the modified Clostridial toxin to an endogenous Clostridial toxin receptor system located at the surface of the target cell. By definition, a naturally-occurring Clostridial toxin lacks an enhanced targeting domain. [019] Aspects of the present invention provide, in part, a Clostridial toxin enzymatic domain. As used herein, the term "Clostridlal toxin enzymatic domain" means any Clostridial toxin polypeptide that can execute the enzymatic target modification step of the intoxication process. Thus, a Clostridial toxin enzymatic domain specifically targets a Clostridial toxin substrate and encompasses the proteolytic cleavage of a Clostridial toxin substrate, such as, e.g., SNARE proteins like a SNAP-25 substrate, a VAMP substrate and a Syntaxin substrate. Non-limiting examples of a Clostridial toxin enzymatic domain include, e.g., a Clostridlal toxin light chain region such as, e.g., a BoNT/A light chain region, a BoNT/B light chain region, a BoNT/C1 light chain region, a BoNT/D light chain region, a BoNT/E light chain region, a BoNT/F light chain region, a BoNT/G light chain region, and a TeNT light chain region. 9 of 316 WO 2006/101809 PCT/US2006/008956 [020] A Clostridial toxin enzymatic domain includes, without limitation, naturally occurring Clostridial toxin light chain variants, such as, e.g., Clostridial toxin light chain isoforms and Clostridial toxin light chain subtypes; non-naturally occurring Clostridial toxin light chain variants, such as, e.g., conservative Clostridial toxin light chain variants, non-conservative Clostridial toxin light chain variants, Clostridial toxin light chain chimerics, active Clostridial toxin light chain fragments thereof, or any combination thereof. [021] As used herein, the term "Clostridial toxin light chain variant,' whether naturally-occurring or non naturally-occurring, means a Clostridial toxin light chain that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent Identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin light chain variants disclosed in the present specification are capable of executing the enzymatic target modification step of the intoxication process. As non-limiting examples, a BoNT/A light chain variant comprising amino acids 1-448 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1 448 of SEQ ID NO: 1; a BoNT/B light chain variant comprising amino acids 1-441 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-441 of SEQ ID NO: 2; a BoNT/C1 light chain variant comprising amino acids 1-449 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-449 of SEQ ID NO: 3; a BoNT/D light chain variant comprising amino acids 1-445 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-445 of SEQ ID NO: 4: a BoNT/E light chain variant comprising amino acids 1-422 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-422 of SEQ ID NO: 5; a BoNT/F light chain variant comprising amino acids 1-439 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-439 of SEQ ID NO: 6; a BoNT/G light chain variant comprising amino acids 1-446 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-446 of SEQ ID NO: 7; and a TeNT light chain variant comprising amino acids 1 457 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-457 of SEQ ID NO: 8. [022] It Is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin light chain variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific light chain subtypes showing approximately 95% amino acid Identity when compared to another BoNT/A light chain subtype. As used herein, the term "naturally occurring Clostridlal toxin light chain variant" means any Clostridial toxin light chain produced by a naturally-occurring process, including, without limitation, Clostridial toxin 10 of 316 WO 2006/101809 PCT/US2006/008956 light chain isoforms produced from alternatively-spliced transcripts, Clostridial toxin light chain isoforms produced by spontaneous mutation and Clostridial toxin light chain subtypes. A naturally occurring Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain In any aspect of the present invention. A naturally occurring Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant Is based. A naturally occurring Clostridlal toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based. [023] A non-limiting examples of a naturally occurring Clostridial toxin light chain variant is a Clostridial toxin light chain isoform such as, e.g., a BoNT/A light chain isoform, a BoNT/B light chain isoform, a BoNT/C1 light chain isoform, a BoNT/D light chain isoform, a BoNT/E light chain Isoform, a BoNT/F light chain isoform, a BoNT/G light chain isoform, and a TeNT light chain isoform. A Clostridial toxin light chain Isoform can function in substantially the same manner as the reference Clostridial toxin light chain on which the Clostridial toxin light chain isoform is based, and can be substituted for the reference Clostridial toxin light chain In any aspect of the present invention. [024] Another non-limiting examples of a naturally occurring Clostridial toxin light chain variant is a Clostridial toxin light chain subtype such as, e.g., a light chain from subtype BoNT/Al, BoNT/A2, BoNT/A3 and BoNT/A4; a light chain from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a light chain from subtype BoNT/C1-1 and BoNT/C1-2; a light chain from subtype BoNT/El, BoNT/E2 and BoNT/E3; and a light chain from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4.. A Clostridial toxin light chain subtype can function in substantially the same manner as the reference Clostridial toxin light chain on which the Clostridlal toxin light chain subtype is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention. [025] As used herein, the term "non-naturally occurring Clostridial toxin light chain variant" means any Clostridial toxin light chain produced with the aid of human manipulation, including, without limitation, Clostridial toxin light chains produced by genetic engineering using random mutagenesis or rational design and Clostridial toxin light chains produced by chemical synthesis. Non-limiting examples of non naturally occurring Clostridial toxin light chain variants include, e.g., conservative Clostridial toxin light 11 of 316 WO 2006/101809 PCT/US2006/008956 chain variants, non-conservative Clostridial toxin light chain variants, Clostridial toxin light chain chimeric variants and active Clostridial toxin light chain fragments. [026] As used herein, the term "conservative Clostridial toxin light chain variant" means a Clostridial toxin light chain that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin light chain sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridlal toxin light chain on which the conservative Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain In any aspect of the present invention. A conservative Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant Is based. A conservative Clostridial toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based, that possess at least 50% amino acid identity, 65% amino acid Identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based. Non-limiting examples of a conservative Clostridial toxin light chain variant include, e.g., conservative BoNT/A light chain variants, conservative BoNT/B light chain variants, conservative BoNT/Cl light chain variants, conservative BoNT/D light chain variants, conservative BoNT/E light chain variants, conservative BoNT/F light chain variants, conservative BoNT/G light chain variants, and conservative TeNT light chain variants. (027] As used herein, the term "non-conservative Clostridial toxin light chain variant" means a Clostridial toxin light chain in which 1) at least one amino acid is deleted from the reference Clostridial toxin light chain on which the non-conservative Ciostridial toxin light chain variant is based; 2) at least one amino acid added to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin light chain sequence (Table 1). A non-conservative Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain In any aspect of the present invention. A non-conservative Clostridial toxin 12 of 316 WO 2006/101809 PCT/US2006/008956 light chain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant Is based, that possess at least 50% amino acid Identity, 65% amino acid identity, 75% amino acid Identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. Non-limiting examples of a non-conservative Clostridial toxin light chain variant include, e.g., non conservative BoNT/A light chain variants, non-conservative BoNT/B light chain variants, non-conservative BoNT/C1 light chain variants, non-conservative BoNT/D light chain variants, non-conservative BoNT/E light chain variants, non-conservative BoNT/F light chain variants, non-conservative BoNT/G light chain variants, and non-conservative TeNT light chain variants. [028] As used herein, the term "Clostridial toxin light chain chimeric" means a polypeptide comprising at least a portion of a Clostridlal toxin light chain and at least a portion of at least one other polypeptide to form a toxin light chain with at least one property different from the reference Clostridial toxin light chains of Table 1, with the proviso that this Clostridial toxin light chain chimeric is still capable of specifically targeting the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. Such Clostridial toxin light chain chimerics are described in, e.g., Lance E. Steward et al., Leucine-based Motif and Clostridlal Toxins, U.S. Patent Publication 2003/0027752 (Feb. 6, 2003); Lance E. Steward et al., Clostridlal Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2003/0219462 (Nov. 27, 2003); and Lance E. Steward et al., Clostridial Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2004/0220386 (Nov. 4, 2004). [029] As used herein, the term "active Clostridial toxin light chain fragment means any of a variety of Clostridial toxin fragments comprising the light chain can be useful in aspects of the present invention with the proviso that these light chain fragments can specifically target the core components of the 13 of 316 WO 2006/101809 PCTUS2006/008956 neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The light chains of Clostridial toxins are approximately 420-460 amino acids in length and comprise an enzymatic domain (Table 1). Research has shown that the entire length of a Clostridial toxin light chain is not necessary for the enzymatic activity of the enzymatic domain. As a non-limiting example, the first eight amino acids of the BoNT/A light chain (residues 1-8 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the first eight amino acids of the TeNT light chain (residues 1-8 of SEQ ID NO: 8) are not required for enzymatic activity. Likewise, the carboxyl-terminus of the light chain is not necessary for activity. As a non-limiting example, the last 32 amino acids of the BoNT/A light chain (residues 417-448 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the last 31 amino acids of the TeNT light chain (residues 427-457 of SEQ ID NO: 8) are not required for enzymatic activity. Thus, aspects of this embodiment can include Clostridial toxin light chains comprising an enzymatic domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids, at least 425 amino acids and at least 450 amino acids. Other aspects of this embodiment can include Clostridial toxin light chains comprising an enzymatic domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids, at most 425 amino acids and at most 450 amino acids. [030] Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin light chain variants and non-naturally-occurring Clostridial toxin light chain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein. [031] Global methods align sequences from the beginning to the end of the molecule and determine the best alignment by adding up scores of individual residue pairs and by imposing gap penalties. Non limiting methods include, e.g., CLUSTAL W, see, e.g., Julie D. Thompson et al., CLUSTAL W: Improving the Sensitivity of Progressive Multiple Sequence Alignment Through Sequence Weighting, Position Specific Gap Penalties and Weight Matrix Choice, 22(22) Nucleic Acids Research 4673-4680 (1994); and iterative refinement, see, e.g., Osamu Gotoh, Significant Improvement in Accuracy of Multiple Protein Sequence Alignments by Iterative Refinement as Assessed by Reference to Structural Alignments, 264(4) J. Mol. Biol. 823-838 (1996). [032] Local methods align sequences by identifying one or more conserved motifs shared by all of the input sequences. Non-limiting methods include, e.g., Match-box, see, e.g., Eric Deplereux and Ernest Feytmans, Match-Box: A Fundamentally New Algorithm for the Simultaneous Alignment of Several Protein Sequences, 8(5) CABIOS 501-509 (1992); Gibbs sampling, see, e.g., C. E. Lawrence et al., Detecting Subtle Sequence Signals: A Gibbs Sampling Strategy for Multiple Alignment, 262(5131) 14 of 316 WO 2006/101809 PCT/US2006/008956 Science 208-214 (1993); Align-M, see, e.g., Ivo Van Walle et al., Align-M - A New Algorithm for Multiple Alignment of Highly Divergent Sequences, 20(9) Bioinformatics,:1428-1435 (2004). [033] Hybrid methods combine functional aspects of both global and local alignment methods. Non limiting methods include, e.g., segment-to-segment comparison, see, e.g., Burkhard Morgenstem et al., Multiple DNA and Protein Sequence Alignment Based On Segment-To-Segment Comparison, 93(22) Proc. NatI. Acad. Sci. U.S.A. 12098-12103 (1996); T-Coffee, see, e.g., C6dric Notredame et al., T-Coffee: A Novel Algorithm for Multiple Sequence Alignment, 302(1) J. Mol. Biol. 205-217 (2000); MUSCLE, see, e.g., Robert C. Edgar, MUSCLE: Multiple Sequence Alignment With High Score Accuracy and High Throughput, 32(5) Nucleic Acids Res. 1792-1797 (2004); and DIALIGN-T, see, e.g., Amarendran R Subramanian et al., DIALIGN-T: An Improved Algorithm for Segment-Based Multiple Sequence Alignment, 6(1) BMC Bioinformatics 66 (2005). [034] Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification comprises a Clostridial toxin enzymatic domain. In an aspect of this embodiment, a Clostridial toxin enzymatic domain comprises a naturally occurring Clostridial toxin light chain variant, such as, e.g., a Clostridial toxin light chain isoform or a Clostridial toxin light chain subtype. In another aspect of this embodiment, a Clostridial toxin enzymatic domain comprises a non-naturally occurring Clostridial toxin light chain variant, such as, e.g., a conservative Clostridial toxin light chain variant, a non-conservative Clostridial toxin light chain variant, a Clostridial toxin chimeric light chain, an active Clostridial toxin light chain fragment, or any combination thereof. [035] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/A light chain. In an aspect of this embodiment, a BoNT/A light chain comprises amino acids 1-448 of SEQ ID NO: 1. In another aspect of this embodiment, a BoNT/A light chain comprises a naturally occurring BoNT/A light chain variant, such as, e.g., a light chain from a BoNT/A isoform or a light chain from a BoNT/A subtype. In another aspect of this embodiment, a BoNT/A light chain comprises amino acids 1-448 of a naturally occurring BoNT/A light chain variant of SEQ ID NO: 1, such as, e.g., amino acids 1-448 of a BoNT/A isoform of SEQ ID NO: 1 or amino acids 1-448 of a BoNT/A subtype of SEQ ID NO: 1. In still another aspect of this embodiment, a BoNT/A light chain comprises a non-naturally occurring BoNT/A light chain variant, such as, e.g., a conservative BoNT/A light chain variant, a non-conservative BoNT/A light chain variant, a BoNT/A chimeric light chain, an active BoNT/A light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/A light chain comprises amino acids 1-448 of a non naturally occurring BoNT/A light chain variant of SEQ ID NO: 1, such as, e.g., amino acids 1-448 of a conservative BoNT/A light chain variant of SEQ ID NO: 1, amino acids 1-448 of a non-conservative BoNT/A light chain variant of SEQ ID NO: 1, amino acids 1-448 of an active BoNT/A light chain fragment of SEQ ID NO: 1, or any combination thereof. 15 of 316 WO 2006/101809 PCTIUS2006/008956 [036] In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids -1-448 of SEQ ID NO: 1, at least 75% amino acid Identity with amino acids 1-448 of SEQ ID NO: 1, at least 80% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 85% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 90% amino acid Identity with amino acids 1-448 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 1-448 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1-448 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 80% amino acid Identity with amino acids 1-448 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 1-448 of SEQ ID NO: 1 or at most 95% amino acid identity with amino acids 1-448 of SEQ ID NO: 1. [037] In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. [038] In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. in yet other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid 16 of 316 WO 2006/101809 PCT/US2006/008956 deletions relative to amino acids 1-448 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. [039] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/B light chain. In an aspect of this embodiment, a BoNT/B light chain comprises amino acids 1-441 of SEQ ID NO: 2. in another aspect of this embodiment, a BoNT/B light chain comprises a naturally occurring BoNT/B light chain variant, such as, e.g., a light chain from a BoNT/B Isoform or a light chain from a BoNT/B subtype. In another aspect of this embodiment, a BoNT/B light chain comprises amino acids 1-441 of a naturally occurring BoNT/B light chain variant of SEQ ID NO: 2, such as, e.g., amino acids 1-441 of a BoNT/B isoform of SEQ ID NO: 2 or amino acids 1-441 of a BoNT/B subtype of SEQ ID NO: 2. In still another aspect of this embodiment, a BoNT/B light chain comprises a non-naturally occurring BoNT/B light chain variant, such as, e.g., a conservative BoNT/B light chain variant, a non-conservative BoNT/B light chain variant, a BoNT/B chimeric light chain, an active BoNT/B light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/B light chain comprises amino acids 1-441 of a non naturally occurring BoNT/B light chain variant of SEQ ID NO: 2, such as, e.g., amino acids 1-441 of a conservative BoNT/B light chain variant of SEQ ID NO: 2, amino acids 1-441 of a non-conservative BoNT/B light chain variant of SEQ ID NO: 2, amino acids 1-441 of an active BoNT/B light chain fragment of SEQ ID NO: 2, or any combination thereof. [040] In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 80% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 85% amino acid Identity with amino acids 1-441 of SEQ ID NO: 2, at least 90% amino acid identity with amino acids 1-441 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 75% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 1-441 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 1-441 of SEQ ID NO: 2. [041] In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, 17 of 316 WO 2006/101809 PCT/US2006/008956 five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. [042] In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. [043] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/C1 light chain. In an aspect of this embodiment, a BoNT/Cl light chain comprises amino acids 1-449 of SEQ ID NO: 3. In another aspect of this embodiment, a BoNT/C1 light chain comprises a naturally occurring BoNT/Cl light chain variant, such as, e.g., a light chain from a BoNT/C1 isoform or a light chain from a BoNT/C1 subtype. In another aspect of this embodiment, a BoNT/Ci light chain comprises amino acids 1-449 of a naturally occurring BoNT/C1 light chain variant of SEQ ID NO: 3, such as, e.g., amino acids 1-449 of a BoNT/C1 isoform of SEQ ID NO: 3 or amino acids 1-449 of a BoNT/C1 subtype of SEQ ID NO: 3. In still another aspect of this embodiment, a BoNT/C1 light chain comprises a non-naturally occurring BoNT/C1 light chain variant, such as, e.g., a conservative BoNT/C1 light chain variant, a non-conservative 18 of 316 WO 2006/101809 PCT/US2006/008956 BoNT/Ci light chain variant, a BoNT/C1 chimeric light chain, an active BoNT/C1 light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/C1 light chain comprises amino acids 1-449 of a non-naturally occurring BoNT/C1 light chain variant of SEQ ID NO: 3, such as, e.g., amino acids 1-449 of a conservative BoNT/C1 light chain variant of SEQ ID NO: 3, amino acids 1 449 of a non-conservative BoNT/C1 light chain variant of SEQ iD NO: 3, amino acids 1-449 of an active BoNT/C1 light chain fragment of SEQ ID NO: 3, or any combination thereof. [044] In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 90% amino acid Identity with amino acids 1-449 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 1-449 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 1-449 of SEQ ID NO: 3. [045] In other aspects of this embodiment, a BoNT/Cl light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/Cl light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletIons relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. [046] In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this 19 of 316 WO 2006/101809 PCT/US2006/008956 embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/CI light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. [0471 In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/D light chain. In an aspect of this embodiment, a BoNT/D light chain comprises amino acids 1-445 of SEQ ID NO: 4. In another aspect of this embodiment, a BoNT/D light chain comprises a naturally occurring BoNT/D light chain variant, such as, e.g., a light chain from a BoNT/D isoform or a light chain from a BoNT/D subtype. In another aspect of this embodiment, a BoNT/D light chain comprises amino acids 1-445 of a naturally occurring BoNT/D light chain variant of SEQ ID NO: 4, such as, e.g., amino acids 1-445 of a BoNT/D isoform of SEQ ID NO: 4 or amino acids 1-445 of a BoNT/D subtype of SEQ ID NO: 4. In still another aspect of this embodiment, a BoNT/D light chain comprises a non-naturally occurring BoNT/D light chain variant, such as, e.g., a conservative BoNT/D light chain variant, a non-conservative BoNT/D light chain variant, a BoNT/D chimeric light chain, an active BoNT/D light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/D light chain comprises amino acids 1-445 of a non naturally occurring BoNT/D light chain variant of SEQ ID NO: 4, such as, e.g., amino acids 1-445 of a conservative BoNT/D light chain variant of SEQ ID NO: 4, amino acids 1-445 of a non-conservative BoNT/D light chain variant of SEQ ID NO: 4, amino acids 1-445 of an active BoNT/D light chain fragment of SEQ ID NO: 4, or any combination thereof. [048] In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 1-445 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 1-445 20 of 316 WO 2006/101809 PCT/US2006/008956 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 1-445 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 1-445 of SEQ ID NO: 4. [049] In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. [050] In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. [051] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/E light chain. In an aspect of this embodiment, a BoNT/E light chain comprises amino acids 1-422 of SEQ ID NO: 5. In 21 of 316 WO 2006/101809 PCT/US2006/008956 another aspect of this embodiment, a BoNT/E light chain comprises a naturally occurring BoNT/E light chain variant, such as, e.g., a light chain from a BoNT/E isoform or a light chain from a BoNT/E subtype. In another aspect of this embodiment, a BoNT/E light chain comprises amino acids 1-422 of a naturally occurring BoNT/E light chain variant of SEQ ID NO: 5, such as, e.g., amino acids 1-422 of a BoNT/E isoform of SEQ ID NO: 5 or amino acids 1-422 of a BoNT/E subtype of SEQ ID NO: 5. In still another aspect of this embodiment, a BoNT/E light chain comprises a non-naturally occurring BoNT/E light chain variant, such as, e.g., a conservative BoNT/E light chain variant, a non-conservative BoNT/E light chain variant, a BoNT/E chimeric light chain, an active BoNT/E light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/E light chain comprises amino acids 1-422 of a non naturally occurring BoNT/E light chain variant of SEQ ID NO: 5, such as, e.g., amino acids 1-422 of a conservative BoNT/E light chain variant of SEQ ID NO: 5, amino acids 1-422 of a non-conservative BoNT/E light chain variant of SEQ ID NO: 5, amino acids 1-422 of an active BoNT/E light chain fragment of SEQ ID NO: 5, or any combination thereof. [052] in other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 5. [053] In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative 22 of 316 WO 2006/101809 PCT/US2006/008956 to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5. (054] In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5. [055] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/F light chain. In an aspect of this embodiment, a BoNT/F light chain comprises amino acids 1-439 of SEQ ID NO: 6. In another aspect of this embodiment, a BoNT/F light chain comprises a naturally occurring BoNT/F light chain variant, such as, e.g., a light chain from a BoNT/F isoform or a light chain from a BoNT/F subtype. In another aspect of this embodiment, a BoNT/F light chain comprises amino acids 1-439 of a naturally occurring BoNT/F light chain variant of SEQ ID NO: 6, such as, e.g., amino acids 1-439 of a BoNT/F isoform of SEQ ID NO: 6 or amino acids 1-439 of a BoNT/F subtype of SEQ ID NO: 6. In still another aspect of this embodiment, a BoNT/F light chain comprises a non-naturally occurring BoNT/F light chain variant, such as, e.g., a conservative BoNT/F light chain variant, a non-conservative BoNT/F light chain variant, a BoNT/F chimeric light chain, an active BoNT/F light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/F light chain comprises amino acids 1-439 of a non naturally occurring BoNT/F light chain variant of SEQ ID NO: 6, such as, e.g., amino acids 1-439 of a conservative BoNT/F light chain variant of SEQ ID NO: 6, amino acids 1-439 of a non-conservative BoNT/F light chain variant of SEQ ID NO: 6, amino acids 1-439 of an active BoNT/F light chain fragment of SEQ ID NO: 6, or any combination thereof. [056] In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 75% amino acid 23 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 1-439 of SEQ ID NO: 6, at least 80% amino acid Identity with amino acids 1-439 of SEQ ID NO: 6, at least 85% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 1-439 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 1-439 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 1-439 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 1-439 of SEQ ID NO: 6. [057] In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. in yet other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNTIF light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. [058] In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNTIF light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, 24 of 316 WO 2006/101809 PCT/US2006/008956 eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. (059] In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/G light chain. In an aspect of this embodiment, a BoNT/G light chain comprises amino acids 1-446 of SEQ ID NO: 7. In another aspect of this embodiment, a BoNT/G light chain comprises a naturally occurring BoNT/G light chain variant, such as, e.g., a light chain from a BoNT/G isoform or a light chain from a BoNT/G subtype. In another aspect of this embodiment, a BoNT/G light chain comprises amino acids 1-446 of a naturally occurring BoNT/G light chain variant of SEQ ID NO: 7, such as, e.g., amino acids 1-446 of a BoNT/G isoform of SEQ ID NO: 7 or amino acids 1-446 of a BoNT/G subtype of SEQ ID NO: 7. In still another aspect of this embodiment, a BoNT/G light chain comprises a non-naturally occurring BoNT/G light chain variant, such as, e.g., a conservative BoNT/G light chain variant, a non-conservative BoNT/G light chain variant, a BoNT/G chimeric light chain, an active BoNT/G light chain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/G light chain comprises amino acids 1-446 of a non-naturally occurring BoNT/G light chain variant of SEQ ID NO: 7, such as, e.g., amino acids 1-446 of a conservative BoNT/G light chain variant of SEQ ID NO: 7, amino acids 1-446 of a non-conservative BoNT/G light chain variant of SEQ ID NO: 7, amino acids 1-446 of an active BoNT/G light chain fragment of SEQ ID NO: 7, or any combination thereof. [060] In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 75% amino acid Identity with amino acids 1-446 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 1-446 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 75% amino acid Identity with amino acids 1-446 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 1-446 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 1-446 of SEQ ID NO: 7. [061] In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G light 25 of 316 WO 2006/101809 PCT/US2006/008956 chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, tour, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. [062] In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. [0631 In another embodiment, a Clostridial toxin enzymatic domain comprises a TeNT light chain, In an aspect of this embodiment, a TeNT light chain comprises amino acids 1-457 of SEQ ID NO: 8. In another aspect of this embodiment, a TeNT light chain comprises a naturally occurring TeNT light chain variant, such as, e.g., a light chain from a TeNT isoform or a light chain from a TeNT subtype. In another aspect of this embodiment, a TeNT light chain comprises amino acids 1-457 of a naturally occurring TeNT light chain variant of SEQ ID NO: 8, such as, e.g., amino acids 1-457 of a TeNT isoform of SEQ ID NO: 8 or amino acids 1-457 of a TeNT subtype of SEQ ID NO: 8. In still another aspect of this embodiment, a TeNT light chain comprises a non-naturally occurring TeNT light chain variant, such as, e.g., a conservative TeNT light chain variant, a non-conservative TeNT light chain variant, a TeNT chimeric light chain, an active TeNT light chain fragment, or any combination thereof. In still another aspect of this embodiment, a TeNT light chain comprises amino acids 1-457 of a non-naturally occurring TeNT light 26 of 316 WO 2006/101809 PCT/US2006/008956 chain variant of SEQ ID NO: 8, such as, e.g., amino acids 1-457 of a conservative TeNT light chain variant of SEQ ID NO: 8, amino acids 1-457 of a non-conservative TeNT light chain variant of SEQ ID NO: 8, amino acids 1-457 of an active TeNT light chain fragment of SEQ ID NO: 8, or any combination thereof. (0641 In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 75% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 85% amino acid Identity with amino acids 1-457 of SEQ ID NO: 8, at least 90% amino acid Identity with amino acids 1-457 of SEQ ID NO: 8 or at least 95% amino acid Identity with amino acids 1-457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1-457 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 1-457 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 1-457 of SEQ ID NO: 8. [0651 In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1 457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8. [066] In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1 27 of 316 WO 2006/101809 PCT/US2006/008956 457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT light chain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8. [067] Aspects of the present invention provide, in part, a Clostridlal toxin translocation domain. As used herein, the term "Clostridial toxin translocation domain" means any Clostridial toxin polypeptide that can execute the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. Thus, a Clostridial toxin translocation domain facilitates the movement of a Clostridial toxin light chain across a membrane and encompasses the movement of a Clostridial toxin light chain through the membrane an intracellular vesicle Into the cytoplasm of a cell. Non-limiting examples of a Clostridial toxin translocation domain include, e.g., a Clostridial toxin HN region such as, e.g., a BoNT/A HN region, a BoNT/B HN region, a BoNTIC1 HN region, a BoNT/D HN region, a BoNT/E HN region, a BoNT/F HN region, a BoNT/G HN region, and a TeNT HN region. [068] A Clostridial toxin translocation domain includes, without limitation, naturally occurring Clostridial toxin HN region variants, such as, e.g., Clostridial toxin HN region isoforms and Clostridial toxin HN region subtypes; non-naturally occurring Clostridial toxin HN region variants, such as, e.g., conservative Clostridial toxin HN region variants, non-conservative Clostridial toxin HN region variants, Clostridial toxin HN region chimerics, active Clostridial toxin HN region fragments thereof, or any combination thereof. [069] As used herein, the term "Clostridial toxin HN region variant," whether naturally-occurring or non naturally-occurring, means a Clostridial toxin HN region that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin HN region variants disclosed in the present specification are capable of executing the translocation step of the Intoxication process that mediates Clostridial toxin light chain translocation. As non-limiting examples, a BoNT/A HN region variant comprising amino acids 449-871 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 449-871 of SEQ ID NO: 1; a BoNT/B HN region variant comprising amino acids 442-858 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 442-858 of SEQ ID 28 of 316 WO 2006/101809 PCT/US2006/008956 NO: 2; a BoNT/C1 HN region variant comprising amino acids 450-866 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 450-866 of SEQ ID NO: 3; a BoNT/D HN region variant comprising amino acids 446-862 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 446-862 of SEQ ID NO: 4; a BoNT/E HN region variant comprising amino acids 423-845 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 423-845 of SEQ ID NO: 5; a BoNT/F HN region variant comprising amino acids 440-864 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 440-864 of SEQ ID NO: 6; a BoNT/G HN region variant comprising amino acids 447-863 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 447-863 of SEQ ID NO: 7; and a TeNT HN region variant comprising amino acids 458-879 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 458-879 of SEQ ID NO: 8. [070] It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin HN region variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific HN region subtypes showing approximately 87% amino acid Identity when compared to another BoNT/A HN region subtype. As used herein, the term naturally occurring Clostridial toxin HN region variant" means any Clostridial toxin HN region produced by a naturally-occurring process, including, without limitation, Clostridial toxin HN region Isoforms produced from alternatively-spliced transcripts, Clostridial toxin HN region isoforms produced by spontaneous mutation and Clostridial toxin HN region subtypes. A naturally occurring Clostridial toxin HN region variant can function In substantially the same manner as the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present Invention. A naturally occurring Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based. A naturally occurring Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid Identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based. 29 of 316 WO 2006/101809 PCTIUS2006/008956 [071] A non-limiting examples of a naturally occurring Clostridial toxin HN region variant is a Clostridial toxin HN region isoform such as, e.g., a BoNT/A HN region isoform, a BoNT/B HN region isoform, a BoNT/C1 HN region isoform, a BoNT/D HN region isoform, a BoNT/E HN region isoform, a BoNT/F HN region isoform, a BoNT/G HN region isoform, and a TeNT HN region isoform. A Clostridial toxin HN region isoform can function in substantially the same manner as the reference Clostridial toxin HN region on which the Clostridial toxin HN region isoform is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. [072] Another non-limiting examples of a naturally occurring Clostridial toxin HN region variant is a Clostridial toxin HN region subtype such as, e.g., a HN region from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a HN region from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a HN region from subtype BoNT/C1 -1 and BoNT/C1 -2; a HN region from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a HN region from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin HN region subtype can function in substantially the same manner as the reference Clostridial toxin HN region on which the Clostridial toxin HN region subtype is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. [073] As used herein, the term "non-naturally occurring Clostridial toxin HN region variant" means any Clostridial toxin HN region produced with the aid of human manipulation, including, without limitation, Clostridial toxin HN regions produced by genetic engineering using random mutagenesis or rational design and Clostridial toxin HN regions produced by chemical synthesis. Non-limiting examples of non naturally occurring Clostridial toxin HN region variants include, e.g., conservative Clostridial toxin HN region variants, non-conservative Clostridial toxin HN region variants, Clostridial toxin HN region chimeric variants and active Clostridial toxin HN region fragments. [074] As used herein, the term "conservative Clostridial toxin HN region variant" means a Clostridial toxin HN region that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin HN region sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophillcity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin HN region variant can function in substantially the same manner as the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant Is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. A conservative Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino 30 of 316 WO 2006/101809 PCT/US2006/008956 acids, or 500 or more amino acids from the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based. A conservative Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based. Non-limiting examples of a conservative Clostridial toxin HN region variant Include, e.g., conservative BoNT/A HN region variants, conservative BoNT/B HN region variants, conservative BoNT/C1 HN region variants, conservative BoNT/D HN region variants, conservative BoNT/E HN region variants, conservative BoNT/F HN region variants, conservative BoNT/G HN region variants, and conservative TeNT HN region variants. [075] As used herein, the term "non-conservative Clostridial toxin HN region variant" means a Clostridial toxin HN region in which 1) at least one amino acid Is deleted from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based; 2) at least one amino acid added to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin HN region sequence (Table 1). A non-conservative Clostridial toxin HN region variant can function in substantially the same manner as the reference Clostridial toxin HN region on which the non conservative Clostridial toxin HN region variant is based, and can be substituted for the reference Clostridlal toxin HN region in any aspect of the present invention. A non-conservative Clostridial toxin HN region variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant Is based. A non-conservative Clostridial toxin HN region variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. A non-conservative Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. A non-conservative Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant Is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 31 of 316 WO 2006/101809 PCT/US2006/008956 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. Non-limiting examples of a non conservative Clostridial toxin HN region variant include, e.g., non-conservative BoNT/A HN region variants, non-conservative BoNT/B HN region variants, non-conservative BoNT/C1 HN region variants, non conservative BoNT/D HN region variants, non-conservative BoNT/E HN region variants, non-conservative BoNT/F HN region variants, non-conservative BoNT/G HN region variants, and non-conservative TeNT HN region variants. [076] As used herein, the term "Clostridial toxin HN region chimeric" means a polypeptide comprising at least a portion of a Clostridial toxin HN region and at least a portion of at least one other polypeptide to form a toxin HN region with at least one property different from the reference Clostridial toxin HN regions of Table 1, with the proviso that this Clostridial toxin HN region chimeric is still capable of specifically targeting the core components of the neurotransmitter release apparatus and thus participate In executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. [077] As used herein, the term "active Clostridial toxin HN region fragment" means any of a variety of Clostridial toxin fragments comprising the HN region can be useful in aspects of the present invention with the proviso that these active fragments can facilitate the release of the LC from Intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The HN regions from the heavy chains of Clostridial toxins are approximately 410-430 amino acids in length and comprise a translocation domain (Table 1). Research has shown that the entire length of a HN region from a Clostridal toxin heavy chain is not necessary for the translocating activity of the translocation domain. Thus, aspects of this embodiment can include Clostridial toxin HN regions comprising a translocation domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids and at least 425 amino acids. Other aspects of this embodiment can include Clostridial toxin HN regions comprising translocation domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids and at most 425 amino acids. [078] Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin HN region variants and non-naturally-occurring Clostridial toxin HN region variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein. [079] Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification comprises a Clostridial toxin translocation domain. In an aspect of this embodiment, a Clostridial toxin translocation domain comprises a naturally occurring Clostridial toxin HN region variant, such as, e.g., a Clostridial toxin HN region isoform or a Clostridial toxin HN region subtype. In another aspect of this 32 of 316 WO 2006/101809 PCT/US2006/008956 embodiment, a Clostridial toxin translocation domain comprises a non-naturally occurring Clostridlal toxin HN region variant, such as, e.g., a conservative Clostridial toxin HN region variant, a non-conservative Clostridial toxin HN region variant, a Clostridial toxin chimeric HN region, an active Clostridial toxin HN region fragment, or any combination thereof. [080] in another embodiment, a Clostridial toxin translocation domain comprises a BoNT/A HN region. In an aspect of this embodiment, a BoNT/A HN region comprises amino acids 449-871 of SEQ ID NO: 1. In another aspect of this embodiment, a BoNT/A HN region comprises a naturally occurring BoNT/A HN region variant, such as, e.g., a HN region from a BoNT/A isoform or a HN region from a BoNT/A subtype. In another aspect of this embodiment, a BoNT/A HN region comprises amino acids 449-871 of a naturally occurring BoNT/A HN region variant of SEQ ID NO: 1, such as, e.g., amino acids 449-871 of a BoNT/A isoform of SEQ ID NO: 1 or amino acids 449-871 of a BoNT/A subtype of SEQ ID NO: 1. In still another aspect of this embodiment, a BoNT/A HN region comprises a non-naturally occurring BoNT/A HN region variant, such as, e.g., a conservative BoNT/A HN region variant, a non-conservative BoNT/A HN region variant, a BoNT/A chimeric HN region, an active BoNT/A HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/A HN region comprises amino acids 449-871 of a non naturally occurring BoNT/A HN region variant of SEQ ID NO: 1, such as, e.g., amino acids 449-871 of a conservative BoNT/A HN region variant of SEQ ID NO: 1, amino acids 449-871 of a non-conservative BoNT/A HN region variant of SEQ ID NO: 1, amino acids 449-871 of an active BoNT/A HN region fragment of SEQ ID NO: 1, or any combination thereof. [081] in other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 449-871 of SEQ ID NO: 1, at least 75% amino acid identity with amino acids 449-871 of SEQ ID NO: 1, at least 80% amino acid Identity with amino acids 449-871 of SEQ ID NO: 1, at least 85% amino acid Identity with amino acids 449-871 of SEQ ID NO: 1, at least 90/ amino acid identity with amino acids 449-871 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 449-871 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 449 871 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 449-871 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 449-871 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 449-871 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 449-871 of SEQ ID NO: 1 or at most 95% amino acid identity with amino acids 449-871 of SEQ ID NO: 1. [082] In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 449-871 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A HN region 33 of 316 WO 2006/101809 PCT/US2006/008956 comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 449-871 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 449-871 of SEQ ID NO: 1. [083] In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 449-871 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 449-871 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 449-871 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 449-871 of SEQ ID NO: 1. [084] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/B HN region. In an aspect of this embodiment, a BoNT/B HN region comprises amino acids 442-858 of SEQ ID NO: 2. In another aspect of this embodiment, a BoNT/B HN region comprises a naturally occurring BoNT/B HN region variant, such as, e.g., a HN region from a BoNT/B isoform or a HN region from a BoNT/B subtype. In another aspect of this embodiment, a BoNT/B HN region comprises amino acids 442-858 of a naturally occurring BoNT/B HN region variant of SEQ ID NO: 2, such as, e.g., amino acids 442-858 of a BoNT/B isoform of SEQ ID NO: 2 or amino acids 442-858 of a BoNT/B subtype of SEQ ID NO: 2. In still another aspect of this embodiment, a BoNT/B HN region comprises a non-naturally occurring BoNT/B HN region variant, such as, e.g., a conservative BoNT/B HN region variant, a non-conservative BoNT/B HN region variant, a BoNT/B chimeric HN region, an active BoNT/B HN region fragment, or any combination thereof. 34 of 316 WO 2006/101809 PCT/US2006/008956 In still another aspect of this embodiment, a BoNT/B HN region comprises amino acids 442-858 of a non naturally occurring BoNT/B HN region variant of SEQ ID NO: 2, such as, e.g., amino acids 442-858 of a conservative BoNT/B HN region variant of SEQ ID NO: 2, amino acids 442-858 of a non-conservative BoNT/B HN region variant of SEQ ID NO: 2, amino acids 442-858 of an active BoNT/B HN region fragment of SEQ ID NO: 2, or any combination thereof. [085] In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 442-858 of SEQ ID NO: 2, at least 75% amino acid Identity with amino acids 442-858 of SEQ ID NO: 2, at least 80% amino acid identity with amino acids 442-858 of SEQ ID NO: 2, at least 85% amino acid Identity with amino acids 442-858 of SEQ ID NO: 2, at least 90% amino acid identity with amino acids 442-858 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 442-858 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 442 858 of SEQ ID NO: 2, at most 75% amino acid Identity with amino acids 442-858 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 442-858 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 442-858 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 442-858 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 442-858 of SEQ ID NO: 2. [086] In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 442-858 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 442-858 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 442-858 of SEQ ID NO: 2. [087] In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, 35 of 316 WO 2006/101809 PCT/US2006/008956 a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 442-858 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 442-858 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 442-858 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 442-858 of SEQ ID NO: 2. [088] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/C1 HN region. In an aspect of this embodiment, a BoNT/C1 HN region comprises amino acids 450-866 of SEQ ID NO: 3. In another aspect of this embodiment, a BoNT/C1 HN region comprises a naturally occurring BoNT/C1 HN region variant, such as, e.g., a HN region from a BoNT/C1 isoform or a HN region from a BoNT/C1 subtype. In another aspect of this embodiment, a BoNT/C1 HN region comprises amino acids 450-866 of a naturally occurring BoNT/C1 HN region variant of SEQ ID NO: 3, such as, e.g., amino acids 450-866 of a BoNT/C1 isoform of SEQ ID NO: 3 or amino acids 450-866 of a BoNT/C1 subtype of SEQ ID NO: 3. In still another aspect of this embodiment, a BoNT/C1 HN region comprises a non-naturally occurring BoNT/C1 HN region variant, such as, e.g., a conservative BoNT/C1 HN region variant, a non-conservative BoNT/C1 HN region variant, a BoNT/Cl chimeric HN region, an active BoNT/C1 HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/C1 HN region comprises amino acids 450-866 of a non-naturally occurring BoNT/C1 HN region variant of SEQ ID NO: 3, such as, e.g., amino acids 450-866 of a conservative BoNT/C1 HN region variant of SEQ ID NO: 3, amino acids 450-866 of a non-conservative BoNT/C1 HN region variant of SEQ ID NO: 3, amino acids 450-866 of an active BoNT/C1 HN region fragment of SEQ ID NO: 3, or any combination thereof. [089] In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at least 90% amino acid Identity with amino acids 450-866 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 450-866 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 450 866 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 450-866 of SEQ ID NO: 3, at most 85% amino acid 36 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 450-866 of SEQ ID NO: 3, at most 90% amino acid Identity with amino acids 450-866 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 450-866 of SEQ ID NO: 3. [090] In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 450-866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 450-866 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 450-866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non contiguous amino acid deletions relative to amino acids 450-866 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 450-866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 450-866 of SEQ ID NO: 3. [091] In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 450-866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 450-866 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 450-866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 450-866 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 450 866 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/Cl HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 450-866 of SEQ ID NO: 3. 37 of 316 WO 2006/101809 PCT/US2006/008956 [092] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/D HN region. In an aspect of this embodiment, a BoNT/D HN region comprises amino acids 446-862 of SEQ ID NO: 4. In another aspect of this embodiment, a BoNT/D HN region comprises a naturally occurring BoNT/D HN region variant, such as, e.g., a HN region from a BoNT/D isoform or a HN region from a BoNT/D subtype. In another aspect of this embodiment, a BoNTID HN region comprises amino acids 446-862 of a naturally occurring BoNT/D HN region variant of SEQ ID NO: 4, such as, e.g., amino acids 446-862 of a BoNT/D isoform of SEQ ID NO: 4 or amino acids 446-862 of a BoNT/D subtype of SEQ ID NO: 4. In still another aspect of this embodiment, a BoNT/D HN region comprises a non-naturally occurring BoNT/D HN region variant, such as, e.g., a conservative BoNT/D HN region variant, a non-conservative BoNT/D HN region variant, a BoNT/D chimeric HN region, an active BoNT/D HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/D HN region comprises amino acids 446-862 of a non naturally occurring BoNT/D HN region variant of SEQ ID NO: 4, such as, e.g., amino acids 446-862 of a conservative BoNT/D HN region variant of SEQ ID NO: 4, amino acids 446-862 of a non-conservative BoNT/D HN region variant of SEQ ID NO: 4, amino acids 446-862 of an active BoNT/D HN region fragment of SEQ ID NO: 4, or any combination thereof. [093] In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 446-862 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 446-862 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 446 862 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 446-862 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 446-862 of SEQ ID NO: 4 or at most 95% amino acid Identity with amino acids 446-862 of SEQ ID NO: 4. [094] In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 446-862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acId substitutions relative to amino acids 446-862 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNTID HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 446-862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non contiguous amino acid deletions relative to amino acids 446-862 of SEQ ID NO: 4. In still other aspects 38 of 316 WO 2006/101809 PCT/US2006/008956 of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 446-862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 446-862 of SEQ ID NO: 4. [095] In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 446-862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 446-862 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 446-862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 446-862 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 446 862 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 446-862 of SEQ ID NO: 4. [096] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/E HN region. In an aspect of this embodiment, a BoNT/E HN region comprises amino acids 423-845 of SEQ ID NO: 5. In another aspect of this embodiment, a BoNT/E HN region comprises a naturally occurring BoNT/E HN region variant, such as, e.g., a HN region from a BoNT/E isoform or a HN region from a BoNT/E subtype. In another aspect of this embodiment, a BoNT/E HN region comprises amino acids 423-845 of a naturally occurring BoNT/E HN region variant of SEQ ID NO: 5, such as, e.g., amino acids 423-845 of a BoNT/E isoform of SEQ ID NO: 5 or amino acids 423-845 of a BoNT/E subtype of SEQ ID NO: 5. In still another aspect of this embodiment, a BoNT/E HN region comprises a non-naturally occurring BoNT/E HN region variant, such as, e.g., a conservative BoNT/E HN region variant, a non-conservative BoNT/E HN region variant, a BoNT/E chimeric HN region, an active BoNT/E HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/E HN region comprises amino acids 423-845 of a non naturally occurring BoNT/E HN region variant of SEQ ID NO: 5, such as, e.g., amino acids 423-845 of a conservative BoNT/E HN region variant of SEQ ID NO: 5, amino acids 423-845 of a non-conservative BoNT/E HN region variant of SEQ ID NO: 5, amino acids 423-845 of an active BoNT/E HN region fragment of SEQ ID NO: 5, or any combination thereof. 39 of 316 WO 2006/101809 PCTIUS2006/008956 [097] In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 423-845 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 423-845 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 423 845 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 423-845 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 423-845 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 423-845 of SEQ ID NO: 5. [098] In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 423-845 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 423-845 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-845 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-845 of SEQ ID NO: 5. in still other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-845 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-845 of SEQ ID NO: 5. [099] In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-845 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-845 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-845 of SEQ ID NO: 5. In other 40 of 316 WO 2006/101809 PCTIUS2006/008956 aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-845 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-845 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-845 of SEQ ID NO: 5. [0100] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/F HN region. In an aspect of this embodiment, a BoNT/F HN region comprises amino acids 440-864 of SEQ ID NO: 6. In another aspect of this embodiment, a BoNT/F HN region comprises a naturally occurring BoNT/F HN region variant, such as, e.g., a HN region from a BoNT/F isoform or a HN region from a BoNT/F subtype. In another aspect of this embodiment, a BoNTIF HN region comprises amino acids 440-864 of a naturally occurring BoNT/F HN region variant of SEQ ID NO: 6, such as, e.g., amino acids 440-864 of a BoNT/F isoform of SEQ ID NO: 6 or amino acids 440-864 of a BoNT/F subtype of SEQ ID NO: 6. In still another aspect of this embodiment, a BoNT/F HN region comprises a non-naturally occurring BoNT/F HN region variant, such as, e.g., a conservative BoNT/F HN region variant, a non-conservative BoNT/F HN region variant, a BoNT/F chimeric HN region, an active BoNT/F HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/F HN region comprises amino acids 440-864 of a non naturally occurring BoNT/F HN region variant of SEQ ID NO: 6, such as, e.g., amino acids 440-864 of a conservative BoNT/F HN region variant of SEQ ID NO: 6, amino acids 440-864 of a non-conservative BoNT/F HN region variant of SEQ ID NO: 6, amino acids 440-864 of an active BoNT/F HN region fragment of SEQ ID NO: 6, or any combination thereof. [0101] In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 440-864 of SEQ ID NO: 6, at least 75% amino acid Identity with amino acids 440-864 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 440-864 of SEQ ID NO: 6, at least 85% amino acid Identity with amino acids 440-864 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 440-864 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 440-864 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 440 864 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 440-864 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 440-864 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 440-864 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 440-864 oi SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 440-864 of SEQ ID NO: 6. [0102] In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous 41 of 316 WO 2006/101809 PCT/US2006/008956 amino acid substitutions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 440-864 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 440-864 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 440-864 of SEQ ID NO: 6. [0103] In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 440-864 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 440-864 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 440-864 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 440-864 of SEQ ID NO: 6. [0104] In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/G HN region. In an aspect of this embodiment, a BoNT/G HN region comprises amino acids 447-863 of SEQ ID NO: 7. In another aspect of this embodiment, a BoNT/G HN region comprises a naturally occurring BoNT/G HN region variant, such as, e.g., a HN region from a BoNT/G isoform or a HN region from a BoNT/G subtype. In another aspect of this embodiment, a BoNT/G HN region comprises amino acids 447-863 of a naturally occurring BoNT/G HN region variant of SEQ ID NO: 7, such as, e.g., amino acids 447-863 of a BoNT/G 42 of 316 - WO 2006/101809 PCTIUS2006/008956 isoform of SEQ ID NO: 7 or amino acids 447-863 of a BoNT/G subtype of SEQ ID NO: 7. in still another aspect of this embodiment, a BoNT/G HN region comprises a non-naturally occurring BoNT/G HN region variant, such as, e.g., a conservative BoNT/G HN region variant, a non-conservative BoNT/G HN region variant, a BoNT/G chimeric HN region, an active BoNT/G HN region fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/G HN region comprises amino acids 447-863 of a non naturally occurring BoNT/G HN region variant of SEQ ID NO: 7, such as, e.g., amino acids 447-863 of a conservative BoNT/G HN region variant of SEQ ID NO: 7, amino acids 447-863 of a non-conservative BoNT/G HN region variant of SEQ ID NO: 7, amino acids 447-863 of an active BoNT/G HN region fragment of SEQ ID NO: 7, or any combination thereof. [0105] In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 447-863 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 447-863 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 447 863 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 447-863 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 447-863 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 447-863 of SEQ ID NO: 7. [0106] In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 447-863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 447-863 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 447-863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non contiguous amino acid deletions relative to amino acids 447-863 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 447-863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 447-863 of SEQ ID NO: 7. 43 of 316 WO 2006/101809 PCT/US2006/008956 [0107] In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 447-863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 447-863 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 447-863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 447-863 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 447 863 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 447-863 of SEQ ID NO: 7. [0108] In another embodiment, a Clostridial toxin translocation domain comprises a TeNT HN region. In an aspect of this embodiment, a TeNT HN region comprises amino acids 458-879 of SEQ ID NO: 8. In another aspect of this embodiment, a TeNT HN region comprises a naturally occurring TeNT HN region variant, such as, e.g., a HN region from a TeNT isoform or a HN region from a TeNT subtype. In another aspect of this embodiment, a TeNT HN region comprises amino acids 458-879 of a naturally occurring TeNT HN region variant of SEQ ID NO: 8, such as, e.g., amino acids 458-879 of a TeNT isoform of SEQ ID NO: 8 or amino acids 458-879 of a TeNT subtype of SEQ ID NO: 8. In still another aspect of this embodiment, a TeNT HN region comprises a non-naturally occurring TeNT HN region variant, such as, e.g., a conservative TeNT HN region variant, a non-conservative TeNT HN region variant, a TeNT chimeric HN region, an active TeNT HN region fragment, or any combination thereof. In still another aspect of this embodiment, a TeNT HN region comprises amino acids 458-879 of a non-naturally occurring TeNT HN region variant of SEQ ID NO: 8, such as, e.g., amino acids 458-879 of a conservative TeNT HN region variant of SEQ ID NO: 8, amino acids 458-879 of a non-conservative TeNT HN region variant of SEQ ID NO: 8, amino acids 458-879 of an active TeNT HN region fragment of SEQ ID NO: 8, or any combination thereof. [0109] In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at least 75% amino acid Identity with amino acids 458-879 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at (east 90% amino acid identity with amino acids 458-879 of SEQ ID NO: 8 or at least 95% amino acid 44 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 458-879 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 458-879 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 458-879 of SEQ ID NO: 8 or at most 95% amino acid Identity with amino acids 458-879 of SEQ ID NO: 8. [0110] In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 458-879 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 458-879 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 458-879 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 458-879 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 458-879 of SEQ ID NO: 8. in other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 458-879 of SEQ ID NO: 8. [0111] In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 458-879 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 458-879 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 458-879 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 458-879 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 458-879 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT HN region comprises a polypeptide having, e.g., at 45 of 316 WO 2006/101809 PCT/US2006/008956 least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 458-879 of SEQ ID NO: 8. [0112] Aspects of the present invention provide, in part, an enhanced targeting domain. As used herein, the term "enhanced targeting domain" means any polypeptide that can selectively bind to an endogenous Clostridial toxin receptor system found on a Clostridial toxin target cell and initiate the overall internalization mechanism whereby a Clostridial toxin intoxicates a target cell with the proviso that an enhanced targeting domain is not a naturally-occurring binding domain from a naturally occurring Clostridial toxin. As used herein, the term "selectively" means having a highly preferred activity or effect. As used herein, the term "selectively bind" means a molecule Is able to bind its target receptor system under physiological conditions, or in vitro conditions substantially approximating physiological conditions, to a statistically significantly greater degree relative to other, non-target receptor systems. Thus, with reference to an enhanced targeting domain of the present specification, there is a discriminatory binding of the enhanced targeting domain to an endogenous Clostridial toxin receptor system. [0113] An enhanced targeting domain disclosed in the present specification facilitates the binding activity of the modified Clostridial toxins disclosed in the present specification to an endogenous Clostridial toxin receptor system located at the surface of a Clostridial toxin target cell. As used herein, the term "binding activity" means that one molecule is directly or indirectly contacting another molecule via at least one Intermolecular or intramolecular force, including, without limitation, a covalent bond, an Ionic bond, a metallic bond, a hydrogen bond, a hydrophobic interaction, a van der Waals Interaction, and the like, or any combination thereof. "Bound" and "bind" are considered terms for binding. [0114] As used herein, the term "binding affinity" means how strong a molecule's binding activity is for a particular receptor system. In general, high binding affinity results from greater intermolecular force between a binding domain and its receptor system while low binding affinity involves less intermolecular force between the ligand and its receptor. High binding affinity involves a longer residence time for the binding domain at its receptor binding site than Is the case for low binding affinity. As such, a molecule with a high binding affinity means a lower concentration of that molecule is required to maximally occupy the binding sites of a receptor system and trigger a physiological response. Conversely, low binding affinity means a relatively high concentration of a molecule is required before the receptor binding sites of a receptor system Is maximally occupied and the maximum physiological response is achieved. Thus, modified Clostridial toxins with Increased binding activity due to high binding affinity will allow administration of reduced doses of the toxin, thereby reducing or preventing unwanted side-effects associated with toxin dispersal into non-targeted areas. [0115] As used herein, the term "binding specificity" means how specific a molecule's binding activity Is one particular receptor system. In general, high binding specificity results in a more exclusive interaction with one particular receptor system or subgroup of receptor systems while low binding specificity results 46 of 316 WO 2006/101809 PCT/US2006/008956 in a more promiscuous interaction with a larger group of receptor systems. As such, a molecule with a high binding specificity means that molecule will occupy the binding sites of a particular receptor system and trigger a physiological response. Conversely, low binding specificity means a molecule will occupy the binding sites of a many receptor systems and trigger a multitude of physiological responses. Thus, modified Clostridial toxins with increased binding activity due to high binding specificity will only target a subgroup of Clostridial toxin target cells, thereby reducing the side effects associated with the targeting of all Clostridial toxin target cells. [0116] It is envisioned that any and all enhanced targeting domains can be used to practice aspects of the present Invention, including, without limitation, an enhanced targeting domain that increases binding affinity for an endogenous Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell; and an enhanced targeting domain that Increases binding specificity for a subgroup of endogenous Clostridial toxin receptor systems present on a naturally-occurring Clostridial toxin target cell. As used herein, the term "Clostridial toxin target cell" means a cell that is a naturally occurring target cell for a naturally occurring Clostridial toxin, including, without limitation, motor neurons. [0117] An example of an enhanced targeting domain that increases binding activity for an endogenous Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell, includes, without limitation, a modified Clostridial toxin binding domain with enhanced binding activity, such as, e.g., a modified BoNT/A binding domain with enhanced binding activity, a modified BoNT/B binding domain with enhanced binding activity, a modified BoNT/C1 binding domain with enhanced binding activity, a modified BoNT/D binding domain with enhanced binding activity, a modified BoNT/E binding domain with enhanced binding activity, a modified BoNT/F binding domain with enhanced binding activity, a modified BoNT/G binding domain with enhanced binding activity and a modified TeNT binding domain with enhanced binding activity. Examples of a modified Clostridial toxin binding domain that increase binding activity include, e.g., a modified Clostridial toxin binding domain that increases binding affinity for an endogenous Clostridlal toxin receptor system present on a naturally-occurring Clostridial toxin target cell and a modified Clostridial toxin binding domain that increases binding specificity for a subgroup of endogenous Clostridial toxin receptor systems present on a naturally-occurring Clostridial toxin target cell. [0118] The three-dimensional crystal structures of BoNT/A, BoNT/B and the Hc domain of TeNT indicate that the three functional domains of Clostridial neurotoxins are structurally distinct. The HEXXH consensus motif of the light chain forms the tetrahedral zinc binding pocket of the catalytic site located in a deep cleft on the protein surface that is accessible by a channel. The structure of the HN and Hc domains consists primarily of n-sheet topologies that are linked by a single a-helix. The cylindrical shaped HN domain comprises two long amphipathic a-helices that resemble the coiled-coil motif found in some viral proteins. The HN domain also forms a long unstructured loop called the 'translocation belt,' which wraps around a large negatively charged cleft of the light chain that blocks access of the zinc atom to the catalytic-binding pocket of active site. The Hc domain comprises two distinct structural features of 47 of 316 WO 2006/101809 PCT/US2006/008956 roughly equal size that indicate function. The first, designated the HCN subdomain, is located in the amino half of the He domain. The HCN subdomain forms a p-barrel, jelly-roll fold. The Hoc subdomain is the second subdomain that comprises the Hc domain. This carboxy-terminal subdomain comprises a modified 1-trefoil domain which forms three distinct carbohydrate binding regions that resembles the carbohydrate binding moiety found in many sugar-binding proteins, such as, e.g., serum amyloid P, sialidase, cryia, insecticidal 8-endotoxin and lectins. Biochemical studies indicate that the 0-trefoil domain structure of the Hcc subdomain appears to mediate the binding to specific carbohydrate containing components of the Clostridial toxin receptor system on the cell surface, see, e.g., Krzysztof Ginalski et al., Structure-based Sequence Alignment for the Beta-Trefoil Subdomain of the Clostridial Neurotoxin Family Provides Residue Level Information About the Putative Ganglioside Binding Site, 482(1-2) FEBS Lett. 119-124 (2000). The Hc domain tilts away from the HN domain exposing the surface loops and making them accessible for binding. No contacts occur between the light chain and the H 0 domain. [0119] Proteins containing the structural 1-trefoil domain represents a diverse group of proteins, see, e.g., C. A. Orengo et al., Protein Superfamilles and Domain Superoids, 372 Nature 631-634 (1994). The 1-trefoil domain comprises a six-stranded p-barrel closed off at one end by three 1-hairpin structures that exhibits a characteristic pseudo-threefold axis symmetry. The monomeric structural unit of this three-fold symmetry is referred to as the p-trefoil fold that contains four P-sheets organized as a pair of antiparallel p-sheets. Dividing each of these p-trefoil folds is a 1-hairpin turn. Therefore, in a linear fashion, a P trefoil domain comprises four 1-sheets of the first P-trefoil fold (a-fold), a p-hairpin turn, four p-sheets of the second P-trefoil fold (p-fold), a second p-hairpin turn four S-sheets of the third p-trefoil fold (y fold)(FIG. 2). Because the first hairpin turn is located between the fourth and fifth P-sheets of the 1-trefoil domain, it is designated the 64/15 P-hairpin turn. Likewise, since the second hairpin turn is located between the eight and ninth p-sheets of the 1-trefoil domain, it is designated the 08/09 P-hairpin turn. [0120] Continuing research has elucidated that $4/05 and 18/19 p-hairpin tums are important in conferring the proper pseudo-threefold axis symmetry observed In the p-trefoil domain. Additionally, this work has demonstrated that amino acid changes in these two 1-hairpin turns can increase the stability of the 1-trefoil domain, which in turn results in increased binding activity, see, e.g., Stephen R. Brych et al., Structure and Stability Effects of Mutations Designed to Increase the Primary Sequence Symmetry Within the Core Region of a f-trefoi, 10 Protein Sci. 2587-2599 (2001); Jaewon Kim et al., Alternative Type I and I' Turn Conformations in the A38/9 13-hairpin of Human Acidic Fibroblast Growth Factor, 11 Protein Sci. 459-466 (2002); Jaewon Kim et al., Sequence swapping Does Not Result In Conformation Swapping for the /4/P5 and 38/19 f-hairpin Turns in Human Acidic Fibroblast Growth Factor, 14 Protein Sci. 351 359 (2005). As a non-limiting example, replacement of an amino acid comprising either the 14/p5 hairpin turn or 18/09 1-hairpin turn with a glycine results in increased stabilization of the 1-trefoil domain. Therefore, replacement of amino acids located in the 04/05 and 18/09 P-hairpin turns of the P-trefoil domains present in the binding domain of Clostridial toxins will increase binding activity of such a modified Clostridial toxin by increasing the structural stability of the 1-trefoil domain. The amino acid 48 of 316 WO 2006/101809 PCT/US2006/008956 sequences comprising the B-trefoil domains found in various Clostridial toxins are shown in Table 2. Table 2. 0-trefoll Domains of Clostridial Toxins Amino Acid Sequence Region of Carbohydrate Binding Moieties Protein SEQ ID NO: 4 - -8/09 -fold -hairpin turn -hairpin turn BoNT/A 1 1111-1162 1163-1178 1179-1223 1224-1236 1237-1296 BoNT/B 2 1098-1147 1148-1165 1166-1210 1211-1222 1223-1291 BoNT/CI 3 1112-1150 1151-1166 1167-1218 1219-1229 1230-1291 BoNT/D 4 1099-1137 1138-1153 1154-1207 1208-1218 1219-1276 BoNT/E 5 1086-1129 1130-1146 1147-1190 1191-1198 1199-1252 BoNT/F 6 1106-1152 1153-1171 1172-1213 1214-1221 1222-1274 BoNT/G 7 1106-1153 1154-1172 1173-1218 1219-1230 1231-1297 TeNT 8 1128-1177 1178-1194 1195-1240 1241-1254 1255-1315 10121] As is typical for proteins containing a p-trefoil fold, the overall amino acid sequence Identity of the Ho subdomain between Clostridial toxins is low. However, key residues essential for binding activity have been identified by structural analysis and mutagenesis experiments, see, e.g., Krzysztof Ginalski et al., Structure-based Sequence Alignment for the Beta-Trefoil Subdomain of the Clostridial Neurtoxin Family Provides Residue Level Information About the Putative Gangioside Binding Site, 482(1-2) FEBS Left. 119-124 (2000). For example, analysis of the Hcc subdomain structure by crystallography identified five highly conserved residues critical for forming a shallow surface pocket of a carbohydrate binding moiety. These polar residues make hydrogen bonds with the carbohydrate ring. In BoNT/A these five polar residues are Glu 1203, Phe 1252, Ser 1264, Tyr 1267 and Gly 1279, while in TeNT, these residues are Asp 1222, Thr 1270, Ser 1287, Tyr 1290 and Gly 1300. Additionally, tyrosine residues forming the hydrophilic wall of this pocket were also important (Trp 1266 of BoNT/A and Trp 1289 of TeNT) and tryptophan fluorescence quenching experiments indicated that Trp 1266 of BoNT/A bound carbohydrate molecules. In another studies, photoaffinity labeling experiments revealed that Gin 1270 of BoNT/A and His 1293 of TeNT were also involved In binding carbohydrate molecules. Mutagenesis experiments designed to assay loss-of-function binding activity mutations confirmed the importance of many of the residues described above for BoNT/A and TeNT and extended this analysis to BoNT/B (Glu 1190, His 1241, Typ 1262, Tyr 1263), see, e.g., Andreas Rummel et al., The H-Domaln of Botulnum Neurotoxins A and B Exhibits a Singular Ganglioside Binding Site Displaying Serotype Specific Carbohydrate Interaction, 51(3) Mol. Microbiol. 631-643 (2004). [0122] As used herein, the term "Clostridial toxin binding domain" Is synonomous with "Clostridial toxin Hc region" and means any naturally occurring Clostridial toxin polypeptide that can execute the cell binding step of the intoxication process, including, e.g., the binding of the Clostridial toxin to a toxin specific receptor system located on the plasma membrane surface of a target cell. As used herein, the 49 of 316 WO 2006/101809 PCT/US2006/008956 term "modified Clostridial toxin binding domain" is synonomous with "modified Clostridial toxin Hc region" and means a naturally occurring Clostridial toxin binding domain modified to enhance its cell binding activity for an endogenous Clostridlial toxin receptor system, such as, e.g., a binding affinity or a binding specificity, to a statistically significantly degree relative to the unmodified naturally occurring Clostridial toxin binding domain from which the modified Clostridial toxin binding domain was derived. By definition, a modified Clostridlal toxin binding domain has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. As non-limiting examples, a modified BoNT/A Hc region comprising amino acids 872-1296 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 872 1296 of SEQ ID NO: 1; a modified BoNT/B H 0 region comprising amino acids 859-1291 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 859-1291 of SEQ ID NO: 2; a modified BoNT/C1 Hc region comprising amino acids 867-1291 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 867-1291 of SEQ ID NO: 3; a modified BoNT/D Hc region comprising amino acids 863-1276 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 863-1276 of SEQ ID NO: 4; a modified BoNT/E He region comprising amino acids 846-1252 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 846-1252 of SEQ ID NO: 5; a modified BoNT/F Hc region comprising amino acids 865-1274 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 865-1274 of SEQ ID NO: 6; a modified BoNT/G H 0 region comprising amino acids 864-1297 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 864-1297 of SEQ ID NO: 7; and a modified TeNT Hc region comprising amino acids 880-1315 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 880-1315 of SEQ ID NO: 8. [0123] As another non-limiting examples, a modified BoNT/A H 0 region comprising amino acids 1092 1296 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1092-1296 of SEQ ID NO: 1; a modified BoNT/B Hc region comprising amino acids 1079-1291 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1079-1291 of SEQ ID NO: 2; a modified BoNT/C1 Hc region comprising amino acids 1093-1291 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 2093-1291 of SEQ iD NO: 3; a modified BoNT/D H 0 region comprising amino acids 1080-1276 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the 50 of 316 WO 2006/101809 PCT/US2006/008956 amino acid region 1080-1276 of SEQ ID NO: 4; a modified BoNT/E Hc region comprising amino acids 1067-1252 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1067-1252 of SEQ ID NO: 5; a modified BoNT/F H 0 region comprising amino acids 1087-1274 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1087-1274 of SEQ ID NO: 6; a modified BoNT/G Hc region comprising amino acids 1087-1297 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1087-1297 of SEQ ID NO: 7; and a modified TeNT Hc region comprising amino acids 1109-1315 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1109-1315 of SEQ ID NO: 8. [0124] It is also envisioned that any of a variety of modified Clostridial toxin H 0 region fragments comprising a binding domain with enhanced binding activity can be useful in aspects of the present Invention with the proviso that these active fragments can provide enhanced binding activity of the toxin to the receptor system located at the surface of the target cell. The Hc regions from the heavy chains of Clostridial toxins are approximately 400-440 amino acids in length and comprise a binding domain (Table 1). Research has shown that the entire length of a Hc region from a Clostridial toxin heavy chain is not necessary for the binding activity of the binding domain. Thus, aspects of this embodiment can include Clostridial toxin He regions comprising a binding domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids and at least 425 amino acids. Other aspects of this embodiment can include Clostridial toxin He regions comprising a binding domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids and at most 425 amino acids. [0125] Any of a variety of sequence alignment methods can be used to determine percent identity of a modified Clostridial toxin H 0 region relative to a naturally-occurring Clostridial toxin H 0 region, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein. [0126] One general approach well known to one skilled in the art on how to modify a Clostridial toxin binding domain in order to increase its binding activity for a naturally-occurring Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell involves changing specifically identified amino acids. As described above, amino acids essential to binding activity have been identified and methods useful for determining which amino acid substitutions will enhance binding activity are known to one skilled in the art. For example, recent advances in computational protein design algorithims have markedly Improved capabilities for generating novel proteins with optimized properties, including, enhanced stability, altered substrate specificity, improved binding affinity and optimized 51 of 316 WO 2006/101809 PCT/US2006/008956 pharmacokinetics, see, e.g., Tanja Kortemme et al., Computational redesign of protein-protein interaction specificity, 11(4) Nat. Struct. Mol. Blol. 371-379 (2004); Tanja Kortemme and David Baker, Computational design of protein-protein interactions, 8(1) Curr. Opin. Chem. Biol. 91-97 (2004); Motomu Shimaoka et al., Computational design of an integrin I domain stabilized in the open high affinity conformation, ;7(8) Nat. Struct. Biol. 674-678 (2000); Loic Martin et al., Rational Design of a CD4 Mimic that Inhibits HIV-1 Entry and Exposes Cryptic Neutralization Epitopes, 21(1) Nat. Biotechnol. 71-76 (2003); and Casim A. Sarkar et al., Rational Cytokine Design for Increased Lifetime and Enhanced Potency Using pH-activated "Histidine Switching,"20(9) Nat. Biotechnol. 908-913 (2002). [0127] In addition, methods capable of altering an amino acid present in a Clostridial toxin binding domain, include, without limitation, site-directed mutagenesis, oligonucleotide-directed mutagenesis and site-specific mutagenesis. Non-limiting examples of specific mutagenesis protocols for making mutations in a Clostridial toxin are described in, e.g., Mutagenesis, pp. 13.1-13.105 (Sambrook and Russell, eds., Molecular Cloning A Laboratory Manual, Vol. 3, 3d ed. 2001). In addition, non-limiting examples of well characterized mutagenesis protocols available from commercial vendors Include, without limitation, Altered Sites || in vitro Mutagenesis Systems (Promega Corp., Madison, WI); Erase-a-Base* System (Promega, Madison, WI); GeneTailorTm Site-Directed Mutagenesis System (invitrogen, Inc., Carlsbad, CA); QuikChange *1 Site-Directed Mutagenesis Kits (Stratagene, La Jolla, CA); and TransformerTM Site Directed Mutagenesis Kit (BD-Clontech, Mountain View, CA). [0128] Lastly, methods to test the binding activity of modified Clostridial toxins comprising a modified Clostridial toxin binding domain with enhanced binding activity are also well known to one skilled in the art, see, e.g., Lutea A. A. de Jong et al., Receptor-Binding Assays: Technologies and Applications, 829 J. Chromatogr. B 1-25 (2005). It is envisioned that heterogeneous assay types, homogeneous assay types and non-separating homogeneous assay types can be used to determine the binding activity of a modified Clostridial toxin with enhanced binding activity disclosed in the present specification. In a heterogeneous assay, the free ligand is separated from the bound ligand by, e.g., filtration, centrifugation or dialysis, before measurement of the binding activity. In a homogeneous assay, no separation of the free ligand from the bound ligand is required before measurement of the binding activity. In non separating homogeneous assays, either the ligand or the receptor is immobilized on a solid phase support, in addition to the no separation aspect of all homogeneous assay. Non-limiting examples of heterogeneous, homogeneous and non-separating homogeneous assays Include, e.g., radioactive heterogeneous assays, such as, e.g., filtration assays using radioactive energy transfer, SPA/flash plate assays using radioactive energy transfer; and non-radioactive heterogeneous assays, such as, e.g., filtration assays using fluorescence, FRET assays using fluorescence energy transfer, FP assays using light polarization, single-cell FMAT assays and flow cytometry. In addition, non-limiting examples of well characterized receptor binding protocols available from commercial vendors include, without limitation, Homogeneous Time Resolved Fluorescense-based receptor binding assays (HTRF*; Cisbio International, Bedford, MA); DELFIA*-based receptor binding assays (PerkinElmer Lifesciences, Boston, MA); and 52 of 316 WO 2006/101809 PCT/US2006/008956 AlphaScreenTM -based receptor binding assays (PerkinElmer Lifesciences, Boston, MA). [0129] It Is further envisioned that the binding activity of a modified Clostridia toxin with enhanced binding activity disclosed in the present specification can be determined by affinity chromotography using immobilized receptors and interfacial optical assays, such as, e.g., total internal reflection fluorescence (TIRF) and surface plasmon resonance (SPR). Non-limiting examples of these assays include, e.g., FCS using diffusion mediated intensity fluctuations, SPR using a mass-dependent refractive index, TIRF using a mass-independent refractive index, microarrays using optical intensity changes and QAC using retention volume. [0130] As another general approach well known to one skilled In the art on how to modify a Clostridial toxin binding domain in order to increase Its binding activity for a naturally-occurring Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell involves directed-evolution methods, see, e.g., Andre Kotermann et al., Process for Generating Sequence-Specific Proteases by Directed Evolution and Uses Thereof, U.S. Patent Publication 2004/0072276 (Apr. 15, 2004); Lance E. Steward and Kei Roger Aoki, Evolved Clostridial Toxins with Altered Protease Activity, U.S. Patent Publication 2004/0115727 (Jun. 17, 2004); and L Yuan et al., Laboratory-directed protein evolution, 69(3) Microbiol. Mol. Biol. Rev. 373-392 (2005). [0131] Often the first step of directed evolution is error-prone PCR amplification of the gene of interest or gene recombination when a family of related genes is available. In this case, the gene corresponding to full-length Clostridial toxin or the Hc binding domain alone would be amplified under conditions that yield one to three amino acid substitutions per molecule. The protein would then be expressed and screened for the desired activity (i.e., receptor binding and/or enhanced activity). Any constructs with even a nominal improvement in receptor binding, regardless of the magnitude of the change, would be submitted for additional rounds of evolution. As a result of the random mutagenesis studies, any amino acids displaying improved binding or even dramatically reduced binding could then be submitted to saturation mutagenesis. This is a process in which the codon of interest it completely randomized so that different constructs containing each of the 20 amino acids substituted at the site of interest are generated. [0132] For improvement of receptor binding characteristics, several different screening approaches could be utilized. If the receptor is known the soluble portion of the receptor can be expressed recombinantly for use in SPR binding assays. For example, the soluble portion of the receptor can be expressed as a fusion to streptavidin, polyhistidine tag, etc. and the receptor can then be Immobilized on an appropriate sensor chip. Utilizing a SPR instrument, changes in local refractive index as a result of receptor binding are measured as a change in the SPR angle. The rates of change in the SPR angle can then be analyzed to determine association and dissociation phases and therefore equilibrium constants. This type of assay could be measured either with the full-length Clostridial toxin or the Hc domain. Additionally, binding type assays relying on affinity pull-down experiments with affinity tagged receptors 53 of 316 WO 2006/101809 PCTIUS2006/008956 acting as a "bait molecule" could be used. The modified Clostridial toxin or Hc domains could then be labeled with radioisotopes for analysis of the amount of target protein associated with the bait. Alternatively, radiolabeled ligands can be competed with Clostridial toxin or Hc domain variants that are not labeled. (0133] If the receptor Is not known, variants of full-length Clostridial toxins can be screened using cells that are known to be sensitive to treatment with native the Clostridial toxin. In this case there are several potential readouts for improved receptor binding, including the presence of the Clostridial toxin in the cell, measurement of cleaved SNARE protein by, e.g., Western blot or cell-based FRET activity assay, or inhibition of exocytosis, e.g., a neurotransmitter release assay. [0134] Thus, in an embodiment, a modified Clostridial toxin disclosed In the present specification comprises a modified Clostridial toxin binding domain with enhanced binding activity. In an aspect of this embodiment, a modified Clostridial toxin binding domain comprises a modified Clostridial toxin He region with enhanced binding activity or a modified Clostridial toxin Hc region fragment with enhanced binding activity. In another aspect of this embodiment, a modified Ciostridial toxin binding domain comprises a modified Clostridial toxin Hoc region with enhanced binding activity or a modified Clostridial toxin Hc region fragment with enhanced binding activity. [0135] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/A binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/A binding domain with enhanced binding activity comprises a modified BoNT/A Hc region with enhanced binding activity or a modified BoNT/A He region fragment with enhanced binding activity. In another aspect of this embodiment, a modified BoNT/A binding domain with enhanced binding activity comprises a modified BoNT/A Hcc region with enhanced binding activity or a modified BoNT/A Hc region fragment with enhanced binding activity. [0136] In other aspects of this embodiment, a modified BoNT/A He region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1, at least 75% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1, at least 80% amino acid Identity with amino acids 872-1296 of SEQ ID NO: 1, at least 85% amino acid Identity with amino acids 872-1296 of SEQ ID NO: 1, at least 90% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A He region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 54 of 316 WO 2006/101809 PCT/US2006/008956 872-1296 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 872-1296 of SEQ ID NO: 1 or at most 95% amino acid Identity with amino acids 872-1296 of SEQ ID NO: 1. [0137] In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 872-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 872-1296 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 872 1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 872 1296 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 872-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 872-1296 of SEQ ID NO: 1. [0138] In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 872-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 872-1296 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 872-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 872-1296 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 872-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity 55 of 316 WO 2006/101809 PCT/US2006/008956 comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 872-1296 of SEQ ID NO: 1. [0139] In another embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a modified BoNT/A He region with enhanced binding activity of comprising a modification of amino acids 1111-1296 of SEQ ID NO: 1. In another aspect of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a modified a-fold motif of a 0-trefoil domain of a BoNT/A binding domain, a modified 0-fold motif of a -trefoil domain of a BoNT/A binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/A binding domain. In another aspect of this embodiment, a modified BoNT/A He region with enhanced binding activity comprises a modification to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. (0140] In other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at least 75% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at least 80% amino acid Identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at least 85% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at least 90% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at most 75% amino acid Identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237 1296 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 1111-1162, amino acids 1179 1223, or amino acids 1237-1296 of SEQ ID NO: 1 or at most 95% amino acid identity with amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. [0141] In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In yet other aspects of 56 of 316 WO 2006/101809 PCT/US2006/008956 this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296. of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding actMty comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. [0142] In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1111 1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237 1296 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1111-1162, amino acids 1179-1223, or amino acids 1237-1296 of SEQ ID NO: 1. 57 of 316 WO 2006/101809 PCTIUS2006/008956 [0143] In another embodiment, a modified BoNT/A Ho region with enhanced binding activity comprises a modified BoNT/A Hc region with enhanced binding activity of comprises a modified 04/05 hairpin turn of a p-trefoil domain of a BoNT/A binding domain or a 08/09 hairpin turn of a p-trefoil domain of a BoNT/A binding domain. In another aspect of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a modification of amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. [0144] In other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at least 75% amino acid Identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at least 80% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at least 85% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at least 90% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In yet other aspects of this embodiment, a modified BoNT/A H 0 region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 or at most 95% amino acid Identity with amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. [0145] In other aspects of this embodiment, a modified BoNT/A Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1163 1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with 58 of 316 WO 2006/101809 PCTIUS2006/008956 enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. (0146] In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/A He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In still other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. In other aspects of this embodiment, a modified BoNT/A Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1163-1178 or amino acids 1224-1236 of SEQ ID NO: 1. [0147] In other aspects of this embodiment, a modified BoNT/A H 0 region with enhanced binding activity comprises a substitution of amino acid Trp 1101, Gly 1102, Leu 1105, Tyr 1111, Tyr 1112, Gly 1156, lie 59 of 316 WO 2006/101809 PCT/US2006/008956 1163, Asp 1179, Giu 1203, Phe 1252, Ser 1264, Trp 1266, Tyr 1267, Gin 1270, Gly 1279 or Trp 1282, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/A Hc region. In other aspects of this embodiment, a modified BoNT/A Hc region with enhanced binding activity comprises a deletion of amino acid Trp 1101, Gly 1102, Leu 1105, Tyr 1111, Tyr 1112, Gly 1158, lie 1163, Asp 1179, Glu 1203, Phe 1252, Ser 1264, Trp 1266, Tyr 1267, Gin 1270, Gly 1279 or Trp 1282, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/A Hc region. [0148] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/B binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/B binding domain with enhanced binding activity comprises a modified BoNT/B Hc region with enhanced binding activity or a modified BoNT/B Hc region fragment with enhanced binding activity. in another aspect of this embodiment, a modified BoNT/B binding domain with enhanced binding activity comprises a modified BoNT/B Hcc region with enhanced binding activity or a modified BoNT/B Hc region fragment with enhanced binding activity. {0149] in other aspects of this embodiment, a modified BoNT/B He region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at least 80% amino acid Identity with amino acids 859-1291 of SEQ ID NO: 2, at least 85% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at least 90/o amino acid identity with amino acids 859-1291 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at most 75% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 859-1291 of SEQ ID NO: 2. [0150] In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 859-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 859-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 859 1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, 60 of 316 WO 2006/101809 PCTIUS2006/008956 nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 859 1291 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 859-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 859-1291 of SEQ ID NO: 2. [0151] In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 859-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 859-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 859-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 859-1291 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 859-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 859-1291 of SEQ ID NO: 2. [0152] In another embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a modified BoNT/B Hc region with enhanced binding activity of comprising a modification of amino acids 1098-1291 of SEQ ID NO: 2. In another aspect of this embodiment, a modified BoNT/B He region with enhanced binding activity comprises a modified a-fold motif of a P-trefoil domain of a BoNT/B binding domain, a modified 0-fold motif of a P-trefoil domain of a BoNT/B binding domain, or a modified y-fold motif of a -trefoil domain of a BoNT/B binding domain. In another aspect of this embodiment, a modified BoNTIB He region with enhanced binding activity comprises a modification to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ iD NO: 2. [0153] In other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid 61 of 316 WO 2006/101809 PCT/US2006/008956 Identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at least 80% amino acid Identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at least 85% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at least 90% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at most 75% amino acid Identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223 1291 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 1098-1147, amino acids 1166 1210, or amino acids 1223-1291 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. [0154] In other aspects of this embodiment, a modified BoNT/B He region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a 1-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 62 of 316 WO 2006/101809 PCT/US2006/008956 or 20 non-contiguous amino acid additions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. [0155] In other aspects of this embodiment, a modified BoNT/B Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1098 1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223 1291 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1098-1147, amino acids 1166-1210, or amino acids 1223-1291 of SEQ ID NO: 2. [0156] In another embodiment, a modified BoNT/B Hc region with enhanced binding activity comprises a modified BoNT/B H 0 region with enhanced binding activity of comprises a modified 04/05 hairpin turn of a 0-trefoil domain of a BoNT/B binding domain or a 08/09 hairpin turn of a 0-trefoil domain of a BoNT/B binding domain. In another aspect.of this embodiment, a modified BoNT/B He region with enhanced binding activity comprises a modification of amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. [0157] In other aspects of this embodiment, a modified BoNT/B H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at least 80% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at least 85% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at least 90% amino acid 63 of 316 WO 2006/101809 PCTIUS2006/008956 identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In yet other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at most 75% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. [01581 In other aspects of this embodiment, a modified BoNT/B Hc region comprising a 6-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1148 1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B Hc region comprising a -trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. [0159] In other aspects of this embodiment, a modified BoNT/B H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, 64 of 316 WO 2006/101809 PCT/US2006/008956 five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B He region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/B H 0 region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In still other aspects of this embodiment, a modified BoNT/B He region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. In other aspects of this embodiment, a modified BoNT/B He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1148-1165 or amino acids 1211-1222 of SEQ ID NO: 2. [0160] In other aspects of this embodiment, a modified BoNT/B H 0 region with enhanced binding activity comprises a substitution of amino acid Trp 1088, Gly 1089, Leu 1092, Tyr 1098, Tyr 1099, Gly 1142, Ile 1147, Asp 1165, Glu 1191, Ile 1240, Ser 1260, Trp 1262, Tyr 1263, GIu 1266, Gly 1277 or Trp 1280, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/B He region. In other aspects of this embodiment, a modified BoNT/B He region with enhanced binding activity comprises a deletion of amino acid Trp 1088, Gly 1089, Leu 1092, Tyr 1098, Tyr 1099, Gly 1142, Ile 1147, Asp 1165, Glu 1191, lie 1240, Ser 1260, Trp 1262, Tyr 1263, Glu 1266, Gly 1277 or Trp 1280, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/B H 0 region. [0161] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/Ci binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/C1 binding domain with enhanced binding activity comprises a modified BoNT/C1 He region with enhanced binding activity or a modified BoNT/C1 Hc region fragment with enhanced binding activity. In another aspect of this embodiment, a modified BoNT/C1 binding domain 65 of 316 WO 2006/101809 PCT/US2006/008956 with enhanced binding activity comprises a modified BoNT/C1 Hcc region with enhanced binding activity or a modified BoNT/C1 Hcc region fragment with enhanced binding activity. [0162] In other aspects of this embodiment, a modified BoNT/Cl Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at least 90% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 867-1291 of SEQ ID NO: 3. [0163] In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 867-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 867 1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 867-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 867-1291 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 867-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 867-1291 of SEQ ID NO: 3. [0164] In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 867-1291 of 66 of 316 WO 2006/101809 PCTIUS2006/008956 SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 867-1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 867-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 867-1291 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Ho region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 867-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 867-1291 of SEQ ID NO: 3. [0165] In another embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a modified BoNT/C1 Hc region with enhanced binding activity of comprising a modification of amino acids 1112-1291 of SEQ ID NO: 3. In another aspect of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a modified a-fold motif of a s-trefoil domain of a BoNT/C1 binding domain, a modified -fold motif of a P-trefoil domain of a BoNT/C1 binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/C1 binding domain. In another aspect of this embodiment, a modified BoNT/C1 H 0 region with enhanced binding activity comprises a modification to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. [0166] In other aspects of this embodiment, a modified BoNT/C1 He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at least 90% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1112-1150, amino acids 1167 1218, or amino acids 1230-1291 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 67 of 316 WO 2006/101809 PCT/US2006/008956 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at most 80% amino acid Identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. [0167] In other aspects of this embodiment, a modified BoNT/C1 He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. [0168] In other aspects of this embodiment, a modified BoNT/C1 H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1112 1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide 68 of 316 WO 2006/101809 PCT/US2006/008956 having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1112-1150, amino acids 1167-1218, or amino acids 1230-1291 of SEQ ID NO: 3. [0169] in another embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a modified BoNT/C1 Hc region with enhanced binding activity of comprises a modified 04/p5 hairpin turn of a P-trefoil domain of a BoNT/C1 binding domain or a 08/p9 hairpin turn of a p-trefoil domain of a BoNT/C1 binding domain. In another aspect of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a modification of amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. [0170] In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at least 90% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In yet other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. 69 of 316 WO 2006/101809 PCT/US2006/008956 [0171] In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1151 1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a non-contiguous amino acid. substitution of any amino acid from amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. [0172] In other aspects of this embodiment, a modified BoNT/Ci Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. in other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1151 1166 or amino acids 1219-1229 of SEQ ID NO: 3 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1151 1166 or amino acids 1219-1229 of SEQ ID NO: 3 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, 70 of 316 WO 2006/101809 PCT/US2006/008956 seven, eight, nine or 10 contiguous amino acid deletions relative to amino acias 11b1-1itb or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In still other aspects of this embodiment, a modified BoNT/C1 Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. In other aspects of this embodiment, a modified BoNT/C1 He region comprising a B-trefoli fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1151-1166 or amino acids 1219-1229 of SEQ ID NO: 3. [0173] In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a substitution of amino acid Trp 1102, Gly 1103, Leu 1106, Tyr 1112, Tyr 1113, Gly 1145, lie 1150, Asp 1166, GIu 1196, Ile 1247, Gly 1256, Trp 1258, Tyr 1259, His 1261, Gly 1281 or Trp 1284, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/C1 Hc region. In other aspects of this embodiment, a modified BoNT/C1 Hc region with enhanced binding activity comprises a deletion of amino acid Trp 1102, Gly 1103, Leu 1106, Tyr 1112, Tyr 1113, Gly 1145, lIe 1150, Asp 1166, Glu 1196, lie 1247, Gly 1256, Trp 1258, Tyr 1259, His 1261, Gly 1281 orTrp 1284, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/C1 Hc region. [0174] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/D binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/D binding domain with enhanced binding activity comprises a modified BoNT/D He region with enhanced binding activity or a modified BoNT/D He region fragment with enhanced binding activity. In another aspect of this embodiment, a modified BoNT/D binding domain with enhanced binding activity comprises a modified BoNT/D Hcc region with enhanced binding activity or a modified BoNT/D Hcc region fragment with enhanced binding activity. [0175] In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at most 80% amino acid 71 of 316 WO 2006/101809 PCTIUS2006/008956 Identity with amino acids 863-1276 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 863-1276 of SEQ ID NO: 4. [0176] In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 863-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 863-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 863 1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 863-1276 of SEQ ID NO: 4. in still other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 863-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 863-1276 of SEQ ID NO: 4. [0177] In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 863-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 863-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 863-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 863-1276 of SEQ ID NO: 4. In still other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 863-1276 of SEQ ID NO: 72 of 316 WO 2006/101809 PCT/US2006/008956 4. In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 863-1276 of SEQ ID NO: 4. [0178] in another embodiment, a modified BoNT/D H 0 region with enhanced binding activity comprises a modified BoNT/D He region with enhanced binding activity of comprising a modification of amino acids 1099-1276 of SEQ ID NO: 4. in another aspect of this embodiment, a modified BoNT/D H 0 region with enhanced binding activity comprises a modified a-fold motif of a 1-trefoil domain of a BoNT/D binding domain, a modified 0-fold motif of a P-trefoil domain of a BoNT/D binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/D binding domain. In another aspect of this embodiment, a modified BoNT/D H 0 region with enhanced binding activity comprises a modification to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. [0179] In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefol fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at least 90% amino acid Identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4 or at least 95% amino acid Identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D

H

0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at most 75% amino acid Identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219 1276 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 1099-1137, amino acids 1154 1207, or amino acids 1219-1276 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. [0180] In other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 73 of 316 WO 2006/101809 PCT/US2006/008956 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In still other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoli fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. [0181] in other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1099 1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In still other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1099-1137, amino acids 1154-1207, or amino acids 1219-1276 of SEQ ID NO: 4. 74 of 316 WO 2006/101809 PCT/US2006/008956 [0182] In another embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a modified BoNT/D He region with enhanced binding activity of comprises a modified P4/05 hairpin turn of a P-trefoil domain of a BoNT/D binding domain or a 08/09 hairpin turn of a p-trefoil domain of a BoNT/D binding domain. In another aspect of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a modification of amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. [0183] In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at least 80% amino acid Identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In yet other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. [0184] In other aspects of this embodiment, a modified BoNT/D H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1138 1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In 75 of 316 WO 2006/101809 PCTIUS2006/008956 other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In still other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. [0185] In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In still other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. In other aspects of this embodiment, a modified BoNT/D Hc region comprising a B-trefoIl fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1138-1153 or amino acids 1208-1218 of SEQ ID NO: 4. 76 of 316 WO 2006/101809 PCT/US2006/008956 [0186] In other aspects of this embodiment, a modified BoNT/D Hc region with enhanced binding activity comprises a substitution of amino acid Trip 1089, Gly 1090, Leu 1093, Tyr 1099, Tyr 1100, Gly 1132, lIle 1137, Asp 1153, Asn 1186, Lys 1236, Trp 1238, Arg 1239, Phe 1242, Ser 1262 or Trp 1265, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/D Hc region. In other aspects of this embodiment, a modified BoNT/D He region with enhanced binding activity comprises a deletion of amino acid Trp 1089, Gly 1090, Leu 1093, Tyr 1099, Tyr 1100, Gly 1132, Ile 1137, Asp 1153, Asn 1186, Lys 1236, Trp 1238, Arg 1239, Phe 1242, Ser 1262 or Trp 1265, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/D Hc region. [0187] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/E binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/E binding domain with enhanced binding activity comprises a modified BoNT/E Hc region with enhanced binding activity or a modified BoNT/E Hc region fragment with enhanced binding activity. In another aspect of this embodiment, a modified BoNT/E binding domain with enhanced binding activity comprises a modified BoNT/E Hcc region with enhanced binding activity or a modified BoNT/E Hc region fragment with enhanced binding activity. [0188] in other aspects of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a polypeplide having, e.g., at least 70% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 846-1252 of SEQ ID NO: 5. [0189] in other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 846-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 846-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 846 77 of 316 WO 2006/101809 PCT/US2006/008956 1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 846 1252 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNT/E He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 846-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 846-1252 of SEQ ID NO: 5. [0190] in other aspects of this embodiment, a modified BoNT/E He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 846-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 846-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 846-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 846-1252 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 846-1252 of-SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 846-1252 of SEQ ID NO: 5. [0191] In another embodiment, a modified BoNT/E He region with enhanced binding activity comprises a modified BoNT/E H 0 region with enhanced binding activity of comprising a modification of amino acids 1086-1252 of SEQ ID NO: 5. In another aspect of this embodiment, a modified BoNT/E He region with enhanced binding activity comprises a modified a-fold motif of a p-trefoil domain of a BoNT/E binding domain, a modified 0-fold motif of a 0-trefoil domain of a BoNT/E binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/E binding domain. in another aspect of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a modification to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. 78 of 316 WO 2006/101809 PCTIUS2006/008956 [0192] In other aspects of this embodiment, a modified BoNT/E He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199 1252 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 1086-1129, amino acids 1147 1190, or amino acids 1199-1252 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. [0193] In other aspects of this embodiment, a modified BoNT/E He region comprising a B-trefoil fold domain with enhanced binding actity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E H 0 region comprising a B-treioll fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding 79 of 316 WO 2006/101809 PCT/US2006/008956 activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. [0194] In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1086 1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a 6-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNTIE Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199 1252 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1086-1129, amino acids 1147-1190, or amino acids 1199-1252 of SEQ ID NO: 5. [0195] In another embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a modified BoNT/E Hc region with enhanced binding activity of comprises a modified P4/05 hairpin tum of a p-trefoil domain of a BoNT/E binding domain or a @8/09 hairpin turn of a P-trefoil domain of a BoNT/E binding domain. In another aspect of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a modification of amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. [0196] In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at least 85% amino acid 80 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at least 90% amino acid Identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In yet other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. [0197] In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1130 1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/E Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. 81 of 316 WO 2006/101809 PCT/US2006/008956 [0198] In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In still other aspects of this embodiment, a modified BoNT/E Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. In other aspects of this embodiment, a modified BoNT/E Hc region comprising a -trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1130-1146 or amino acids 1191-1198 of SEQ ID NO: 5. [0199] In other aspects of this embodiment, a modified BoNT/E Hc region with enhanced binding activity comprises a substitution of amino acid Trp 1076, Gly 1077, Leu 1080, Tyr 1086, Tyr 1087, Gly 1124, Ile 1129, Asp 1146, Glu 1172, Phe 1213, Ser 1221, Trp 1223, Tyr 1224, His 1227, Gly 1236 or Trp 1239, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/E Hc region. In other aspects of this embodiment, a modified BoNT/E He region with enhanced binding activity comprises a deletion of amino acid Trp 1076, Gly 1077, Leu 1080, Tyr 1086, Tyr 1087, Gly 1124, lIle 1129, Asp 1146, Giu 1172, Phe 1213, Ser 1221, Trp 1223, Tyr 1224, His 1227, Gly 1236 or Trp 1239, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/E Hc region. [0200] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/F binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/F binding domain with enhanced binding activity comprises a modified BoNT/F Hc region with enhanced binding activity or a modified BoNT/F H 0 region fragment with enhanced 82 of 316 WO 2006/101809 PCT/US2006/008956 binding activity. In another aspect of this embodiment, a modified BoNT/F binding domain with enhanced binding activity comprises a modified BoNT/F Hcc region with enhanced binding activity or a modified BoNT/F Hcc region fragment with enhanced binding activity. [0201) In other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at least 75% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at least 85% amino acid Identity with amino acids 865-1274 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 865-1274 of SEQ ID NO: 6. [0202] In other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 865-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 865-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 865 1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 865 1274 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 865-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 865-1274 of SEQ ID NO: 6. [0203] In other aspects of this embodiment, a modified BoNT/F He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 83 of 316 WO 2006/101809 PCT/US2006/008956 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 865-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 865-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 865-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 865-1274 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 865-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 865-1274 of SEQ ID NO: 6. [0204] In another embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a modified BoNT/F He region with enhanced binding activity of comprising a modification of amino acids 1106-1274 of SEQ ID NO: 6. in another aspect of this embodiment, a modified BoNT/F He region with enhanced binding activity comprises a modified a-fold motif of a P-trefoil domain of a BoNT/F binding domain, a modified p-fold motif of a 0-trefoil domain of a BoNT/F binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/F binding domain. In another aspect of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a modification to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. [0205] In other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at least 75% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at least 85% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 1106-1152, 84 of 316 WO 2006/101809 PCTIUS2006/008956 amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222 1274 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 1106-1152, amino acids 1172 1213, or amino acids 1222-1274 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. [0206] in other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNTIF H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. [0207] in other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1106 1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, 85 of 316 WO 2006/101809 PCT/US2006/008956 e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222 1274 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1106-1152, amino acids 1172-1213, or amino acids 1222-1274 of SEQ ID NO: 6. [0208] In another embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a modified BoNT/F Hc region with enhanced binding activity of comprises a modified 34/P5 hairpin turn of a 0-trefoil domain of a BoNT/F binding domain or a 08/9 hairpin turn of a S-trefoil domain of a BoNT/F binding domain. In another aspect of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a modification of amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. [0209] In other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at least 75% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at least 85% amino acid Identity with amino acids 1153-1171 or amino acids 1214-1221 of SEO ID NO: 6, at least 90% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In yet other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. 86 of 316 WO 2006/101809 PCT/US2006/008956 [0210] In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1153 1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. in other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoli fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. [0211] In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 87 of 316 WO 2006/101809 PCT/US2006/008956 10 contiguous amino acid deletions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In still other aspects of this embodiment, a modified BoNT/F Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. In other aspects of this embodiment, a modified BoNT/F H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1153-1171 or amino acids 1214-1221 of SEQ ID NO: 6. [0212] in other aspects of this embodiment, a modified BoNT/F Hc region with enhanced binding activity comprises a substitution of amino acid Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1147, lie 1152, Asp 1171, Glu 1195, Phe 1237, Ser 1245, Trp 1247, Tyr 1248, Asn 1251, Gly 1260 or Trp 1263, or any combination thereof, the substitution enhancing the binding activity of the modified BoNT/F Hc region. In other aspects of this embodiment, a modified BoNT/F H 0 region with enhanced binding activity comprises a deletion of amino acid Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1147, lie 1152, Asp 1171, Glu 1195, Phe 1237, Ser 1245, Trp 1247, Tyr 1248, Asn 1251, Gly 1260 or Trp 1263, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/F Hc region. [0213] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified BoNT/G binding domain with enhanced binding activity. In an aspect of this embodiment, a modified BoNT/G binding domain with enhanced binding activity comprises a modified BoNT/G H 0 region with enhanced binding activity or a modified BoNT/G H 0 region fragment with enhanced binding activity. In another aspect of this embodiment, a modified BoNT/G binding domain with enhanced binding activity comprises a modified BoNT/G Hc region with enhanced binding activity or a modified BoNT/G Hcc region fragment with enhanced binding activity. [0214] in other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at least 90% amino acid Identity with amino acids 864-1297 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at most 80% amino acid 88 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 864-1297 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 864-1297 of SEQ ID NO: 7. [0215] in other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 864-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 864-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 864 1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 864-1297 of SEQ ID NO: 7. In still other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 864-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 864-1297 of SEQ ID NO: 7. [0216] In other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 864-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 864-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 864-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNTIG Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 864-1297 of SEQ ID NO: 7. In still other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid additions relative to amino acids 864-1297 of SEQ ID NO: 89 of 316 WO 2006/101809 PCT/US2006/008956 7. In other aspects of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 864-1297 of SEQ ID NO: 7. [0217] In another embodiment, a modified BoNT/G He region with enhanced binding activity comprises a modified BoNT/G Hc region with enhanced binding activity of comprising a modification of amino acids 1106-1297 of SEQ ID NO: 7. In another aspect of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a modified a-fold motif of a P-trefoil domain of a BoNT/G binding domain, a modified 0-fold motif of a 0-trefoli domain of a BoNT/G binding domain, or a modified y-fold motif of a P-trefoil domain of a BoNT/G binding domain. In another aspect of this embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a modification to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. [0218] In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231 1297 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 1106-1153, amino acids 1173 1218, or amino acids 1231-1297 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. [0219] In other aspects of this embodiment, a modified BoNT/G Hc region comprising a 6-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 90 of 316 WO 2006/101809 PCT/US2006/008956 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. in other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. in still other aspects of this embodiment, a modified BoNT/G Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. [0220] In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1106 1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G He region comprising a (3-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In still other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1106-1153, amino acids 1173-1218, or amino acids 1231-1297 of SEQ ID NO: 7. 91 of 316 WO 2006/101809 PCT/US2006/008956 [0221] In another embodiment, a modified BoNT/G Hc region with enhanced binding activity comprises a modified BoNT/G Hr region with enhanced binding activity of comprises a modified M/05 hairpin turn of a 0-trefoil domain of a BoNT/G binding domain or a P8/9 hairpin turn of a P-trefoil domain of a BoNT/G binding domain. In another aspect of this embodiment, a modified BoNT/G H 0 region with enhanced binding activity comprises a modification of amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. [0222] In other aspects of this embodiment, a modified BoNT/G He region comprising a B-trefoil fold domain with enhanced binding actity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In yet other aspects of this embodiment, a modified BoNT/G Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. [0223] In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1154 1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNTIG Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In 92 of 316 WO 2006/101809 PCT/US2006/008956 other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In still other aspects of this embodiment, a modified BoNT/G He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoll fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. [0224] In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified BoNT/G He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In still other aspects of this embodiment, a modified BoNT/G He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. In other aspects of this embodiment, a modified BoNT/G H 0 region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1154-1172 or amino acids 1219-1230 of SEQ ID NO: 7. 93 of 316 WO 2006/101809 PCT/US2006/008956 [0225] In other aspects of this embodiment, a modified BoNT/G He region with enhanced binding activity comprises a substitution of amino acid Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1148, ile 1153, Asp 1172, Gin 1198, lie 1245, Ser 1266, Trp 1268, Tyr 1269, Arg 1272, Gly 1283 orTrp 1285, or any combination thereof, the substitution enhancing the binding actMty of the modified BoNT/G He region. In other aspects of this embodiment, a modified BoNT/G He region with enhanced binding activity comprises a deletion of amino acid Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1148, lIle 1153, Asp 1172, Gin 1198, lie 1245, Ser 1266, Trp 1268, Tyr 1269, Arg 1272, Gly 1283 or Trp 1285, or any combination thereof, the deletion enhancing the binding activity of the modified BoNT/G Hc region. [0226] In another embodiment, a modified Clostridial toxin binding domain with enhanced binding activity comprises a modified TeNT binding domain with enhanced binding activity. In an aspect of this embodiment, a modified TeNT binding domain with enhanced binding activity comprises a modified TeNT He region with enhanced binding activity or a modified TeNT He region fragment with enhanced binding activity. In another aspect of this embodiment, a modified TeNT binding domain with enhanced binding activity comprises a modified TeNT Hcc region with enhanced binding activity or a modified TeNT Hc region fragment with enhanced binding activity. [0227] In other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at least 75% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at least 90% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8 or at least 95% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 880-1315 of SEQ ID NO: 8. [0228] in other aspects of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 880-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 880-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 880-1315 of 94 of 316 WO 2006/101809 PCTIUS2006/008956 SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 880-1315 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 880-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 880-1315 of SEQ ID NO: 8. [0229] In other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 880-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 880-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT H 0 region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40 , 50, 100 or 200 contiguous amino acid deletions relative to amino acids 880-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 880-1315 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT He region with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 880-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 880-1315 of SEQ ID NO: 8. [0230] In another embodiment, a modified TeNT H 0 region with enhanced binding activity comprises a modified TeNT He region with enhanced binding activity of comprising, a modification of amino acids 1128-1315 of SEQ ID NO: 8. In another aspect of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a modified a-fold motif of a 0-trefoil domain of a TeNT binding domain, a modified s-fold motif of a P-trefoil domain of a TeNT binding domain, or a modified y-fold motif of a 0-trefoil domain of a TeNT binding domain. In another aspect of this embodiment, a modified TeNT

H

0 region with enhanced binding activity comprises a modification to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. 95 of 316 WO 2006/101809 PCT/US2006/008956 [0231] In other aspects of this embodiment, a modified TeNT Ho region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at least 75% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at least 90/6 amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8 or at least 95% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at most 800/a amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255 1315 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 1128-1177, amino acids 1195 1240, or amino acids 1255-1315 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. [0232] In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT H 0 region comprising a 8-trefoli fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1128 1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT H 0 region comprising a B-trefoil fold domain with enhanced binding activity 96 of 316 WO 2006/101809 PCT/US2006/008956 comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. [0233] In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1128 1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT He region comprising a B-trefol fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1128-1177, amino acids 1195 1240, or amino acids 1255-1315 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. in other aspects of this embodiment, a modified TeNT He region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1128-1177, amino acids 1195-1240, or amino acids 1255-1315 of SEQ ID NO: 8. [0234] In another embodiment, a modified TeNT Hc region with enhanced binding activity comprises a modified TeNT Hc region with enhanced binding activity of comprises a modified p4/p5 hairpin turn of a p trefoil domain of a TeNT binding domain or a 38/P9 hairpin turn of a P-trefoil domain of a TeNT binding domain. In another aspect of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a modification of amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. [0235] In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at least 75% amino acid Identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at least 90% amino acid 97 of 316 WO 2006/101809 PCT/US2006/008956 identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 or at least 95% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In yet other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. [0236] In other aspects of this embodiment, a modified TeNT Hc region comprising a -trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1178 1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid substitutions relative to amino acids 1178-1194 or amino acids 1241 1254 of SEQ ID NO: 8. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid deletions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a 13-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non contiguous amino acid deletions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a 8-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 non-contiguous amino acid additions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. [0237] In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1178-1194 98 of 316 WO 2006/101809 PCT/US2006/008956 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid substitutions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8 can be replaced with phenylalanine. In yet other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid deletions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In still other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. In other aspects of this embodiment, a modified TeNT Hc region comprising a B-trefoil fold domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine or 10 contiguous amino acid additions relative to amino acids 1178-1194 or amino acids 1241-1254 of SEQ ID NO: 8. [0238] In other aspects of this embodiment, a modified TeNT Hc region with enhanced binding activity comprises a substitution of amino acid Trp 1118, Gly 1119, Leu 1122, Tyr 1128, Tyr 1129, Gly 1172, Ile 1177, Asp 1194, Asp 1222, Thr 1270, Ser 1287, Trp 1289, Tyr 1290, His 1293, Gly 1300 or Trp 1303, or any combination thereof, the substitution enhancing the binding activity of the modified TeNT He region. In other aspects of this embodiment, a modified TeNT H 0 region with enhanced binding activity comprises a deletion of amino acid Trp 1118, Gly 1119, Leu 1122, Tyr 1128, Tyr 1129, Gly 1172, Ile 1177, Asp 1194, Asp 1222, Thr 1270, Ser 1287, Trp 1289, Tyr 1290, His 1293, Gly 1300 or Trp 1303, or any combination thereof, the deletion enhancing the binding activity of the modified TeNT Hc region. [0239] Another example of an enhanced targeting domain that increases binding activity for an endogenous Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell, includes, without limitation, non-toxin associated proteins of Clostridial toxins, such as, e.g., non-toxic non-hemagglutinin (NTNH), hemagglutinin-17 (HA-17), hemagglutinin-33 (HA-33) and hemagglutinin-70 (HA-70). In vivo, Ciostridial bacteria produce a toxin complex comprising the approximately 150-kDa Clostridial toxin and other proteins collectively called nontoxin associated proteins (NAPs). Identified NAPs include proteins possessing hemaglutination activity, such, e.g., a hemagglutinin of approximately 99 of 316 WO 2006/101809 PCT/US2006/008956 17-kDa (HA-17), a hemagglutinin of approximately 33-kDa (HA-33) and a hemagglutinin of approximately 70-kDa (HA-70); as well as non-toxic non-hemagglutinin (NTNH), a protein of approximately 130-kDa, see, e.g., Eric A. Johnson and Marite Bradshaw, Clostridial botulinum and its Neurotoxins: A Metabolic and Cellular Perspective, 39 Toxicon 1703-1722 (2001); and Stephanie Raffestin et al., Organization and Regulation of the Neurotoxin Genes In Clostridium botulinum and Clostridium tetani, 10 Anaerobe 93-100 (2004). The toxin complex is important for the intoxication process because it provides protection from adverse environmental conditions, resistance to protease digestion, and appears to facilitate internalization and activation of the toxin. [0240] Recent crystallography experiments have revealed that HA-17, HA-33 and NTNH from various Clostridlal bacteria contain a region comprising B-trefoil domains very similar to the single 0-trefoil domain present in the binding domain of Clostridial toxins, see, e.g., Kaoru Inoue et al., Structural Analysis by X Ray Crystallography and Calorimetry of a Haemagglutinin Component (HA 1) of the Progenitor Toxin from Clostridium botulinum, 149 Microbiol. 3361-3370 (2003); and Joseph W. Arndt et al., The Structure of the Neurotoxin-Associated Protein HA33/A from Clostridial botulinum Suggests a Reoccurring (3-trefoil Fold in the Progenitor Toxin Complex, 346 J. Mol. Biol. 1083-1093 (2005). For example, HA-33 from Clostridium botulinum serotype A has two B-trefoil domains, each of which consists of three potential carbohydrate binding moieties or 0-trefoil folds, designated la (amino acids 10-55 of SEQ ID NO: 9), 1B (amino acids 56-102 of SEQ ID NO: 9) and ly (amino acids 103-144 of SEQ ID NO: 9) for the first 3-trefoil domain and 2a (amino acids 151-197 of SEQ ID NO: 9), 21 (amino acids 198-245 of SEQ ID NO: 9)and 2y (amino acids 246-293 of SEQ ID NO: 9) for the second B-trefoil domain. Mutations in conserved amino acids of the carbohydrate binding moiety result in a loss of carbohydrate binding, see, e.g., Kaoru Inoue et al., Structural Analysis by X-Ray Crystallography and Calorimetry of a Haemagglutinin Component (HA 1) of the Progenitor Toxin from Clostridium botulinum, 149 Microbiol. 3361-3370 (2003). [0241] These B-trefoil domains are also found in the HA-33 proteins produced by Ciostridium botulinum serotype B, serotype C1 and serotype D and sequence alignments revealed that amino acids essential for overall carbohydrate binding are conserved. The amino acids predicted to be essential for carbohydrate binding are as follows Asp 263, Tyr 265, Gin 268, Gin 276, Phe 278 and Gin 286 of HA 33/Al of SEQ ID NO: 9, HA-33/A2 of SEQ ID NO: 10, HA-33/A3 of SEQ ID NO: 11, HA-33/A5 of SEQ ID NO: 12 and HA-33/B2 of SEQ ID NO: 15; Asp 264, Tyr 266, Gin 269, Gin 277, Phe 279 and Gin 287 of HA-33/A4 of SEQ ID NO: 12; Asp 262, Tyr 264, Gin 267, Gin 275, Phe 277 and Gin 285 of HA-33/B1 of SEQ ID NO: 14; Asp 255, Val 257, Gly 260, Gin 268, Typ 270 and GIn 278 of HA-33/C1 of SEQ ID NO: 16; and Asp 256, Tyr 258, GIn 261, Ise 269, Asp 271 and Gin 279 of HA-33/C2 of SEQ ID NO: 17 and HA-33/D of SEQ ID NO: 18. Immunoaffinity column chromatography and pull-down assays have shown that HA-33 can bind synaptotagmin 11, a putative Clostridial toxin receptor, see, e.g., Yu Zhou et al., Haemagglutinin-33 of Type 0 Botulinum Neurotoxin Complex Binds with Synaptotagmin //, 272 FEBS Lett. 2717-2726 (2005). The amino acid sequences comprising the B-trefoil domains found In various Clostridial HA-33 proteins are shown in Tables 3 and 4. 100 of 316 WO 2006/101809 PCT/US2006/008956 Table 3. 13-trefoil Domains of Clostridial HA-33 Proteins SEQ ID Amino Acid Sequence Region of Carbohydrate Binding Moieties Protein NO: la-fold 11 5 16-fold 08 ny-fold HA-33/1 95-hairpin turn 6-ha00ipin turn 10-1 HA-33/A2 9 10-54 55-59 60-100 101-104 105-144 HA-33/A2 10 10-54 55-59 60-100 101-104 105-144 HA-33/A3 11 10-54 55-59 60-100 101-104 105-144 HA-33/A4 12 10-56 57-61 62-102 103-106 107-146 HA-33/A5 13 10-54 55-59 60-100 101-104 105-144 HA-33/B1 14 10-54 55-59 60-100 101-104 105-144 HA-33/B2 15 10-56 57-61 62-102 103-106 107-146 HA-33/C1-1 16 10-54 55-59 60-98 99-102 103-141 HA-33/C1-2 17 10-54 55-59 60-98 99-102 103-141 HA-33/D1 18 10-54 55-59 60-98 99-102 103-141 Table 4._trefoilDomains of Clostridial HA43 Proteins SEQ ID Amino Acid Sequence Region of Carbohydrate Binding Moieties Protein 28-fo d 21ai n ur ___ __ __ _______ 1-hairi tur _ ____ 3-airpin trn HA-33/A1 9 151-195 196-199 200-242 243-248 249-293 HA-33/A2 10 151-195 196-199 200-242 243-248 249-293 HA-33/A3 11 151-195 196-199 200-242 243-248 249-293 HA-33/A4 12 153-197 198-201 202-243 244-249 250-294 HA-33/A5 13 151-195 196-199 200-242 243-248 249-279 HA-33/B1 14 151-195 196-199 200-241 242-247 248-292 HA-33/B2 15 153-197 198-201 200-242 243-248 249-291 HA-33/C1-1 16 148-190 191-194 195-234 235-240 241-285 HA-33/C1-2 17 148-190 191-194 195-235 236-241 242-286 HA-33/D1 18 148-190 191-194 195-235 236-241 242-286 [0242] Further analysis of the 13-trefoil domain sequence of HA-33 also identified 8-trefoil domains in HA 17 and NTNH, see, e.g., Joseph W. Arndt et al., The Structure of the Neurotoxin-Associated Protein HA33/A from Clostridial botulinum Suggests a Reoccurring 8-trefoil Fold in the Progenitor Toxin Complex, 346 J. Mol. Biol. 1083-1093 (2005). The HA-17 comprises a single B-trefoil domain containing three carbohydrate binding moieties or B-trefoil folds. The carbohydrate binding moieties of HA-17 exhibits the greatest sequence similarity with the 2 y carbohydrate binding moiety of HA-33. These B-trefoil domains are also found in the HA-17 proteins produced by Clostridium botulinum serotype B, serotype C1 and serotype D and sequence alignments revealed that amino acids essential for overall carbohydrate binding are conserved. The amino acids predicted to be essential for carbohydrate binding are as follows Tyr 101 of 316 WO 2006/101809 PCT/US2006/008956 110, Typ 112, Tyr 115, Pro 130, Phe 132 and Asn 138 of HA-17/A of SEQ ID NO: 19, HA-17/B of SEQ ID NO: 20, HA-17/C1 of SEQ ID NO: 21 and HA-17/D of SEQ ID NO: 22. The amino acid sequences comprising the B-trefoil domains found in various Clostridial HA-17 proteins are shown In Table 5. Table 5. p-trefoil Domains of Clostridial HA-17 Proteins Amino Acid Sequence Region of Carbohydrate Binding Moieties Protein SEQ ID NO: . a-fol.d _-ha n_ tunhairpn turn __________ HA-17/A 19 9-50 51-54 55-91 92-94 95-146 HA-17/B 20 9-50 51-54 55-91 92-94 95-146 HA-17/C1 21 9-50 51-54 55-91 92-94 95-146 HA-17/D 22 9-50 51-54 55-91 92-94 95-146 [0243] NTNH from various Clostridial bacteria shows significant sequence similarity to the B-trefoil domains present in the cell binding domain of BoNT/A and TeNT. The high degree of structural similarity is interesting in light of the low sequence similarity between NTNH and the Clostridlal toxins. Furthermore, since NTNH of the various serotypes have greater sequence similarity than the Clostridial toxins, it is likely that the NTNH produced by other Clostridial strains will also have B-trefoil domains exhibiting high structural similarity with the binding domains of Clostridial toxins. The B-trefoil domains of various Clostridial NTNHs are as follows: amino acids 1050-1193 of NTNH/A1 of SEQ ID NO: 23; amino acids 1050-1198 of NTNH/A2 of SEQ ID NO: 24; amino acids 1050-1193 of NTNH/A3 of SEQ ID NO: 25; amino acids 1049-1197 of NTNH/B of SEQ ID NO: 26; amino acids 1049-1196 of NTNH/C1 of SEQ ID NO: 27; amino acids 1049-1196 of NTNH/ID of SEQ ID NO: 28; amino acids 1014-1162 of NTNH/E of SEQ ID NO: 29; amino acids 1016-1159 of NTNH/F1 of SEQ ID NO: 30; amino acids 1017-1165 of NTNH/F2 of SEQ ID NO: 31; and amino acids 1050-1198 of NTNH/G of SEQ ID NO: 32. The amino acid sequences comprising the B-trefoil domains found in various Clostridial NTNH proteins are shown In Table 6. [0244] The 8-trefoil domains present in the Clostridial toxin, HA-33, HA-17 and NTNH collectively form nearly half the mass of a Clostridial toxin complex and underlies the apparent importance of carbohydrate binding in the cell binding step of the Intoxication process. This observation is further enhanced by the fact that a Clostridial toxin alone is not as effective in Intoxicating a cell as the entire toxin complex. One potential explanation for this enhanced binding activity is the presence, both in type and in quantity, of the B-trefoil domains present in HA-33, HA-17 and NTNH. Therefore, the high prediction of structural similarity of the B-trefoil domains present in HA-33, HA-17 and NTNH relative to the B-trefoll domain found In Clostridial toxins provides a potential source of binding domains useful for developing modified Clostridial toxins with enhanced binding activity. As a non-limiting example, a carbohydrate binding moiety or a B-trefoil fold from HA-33, HA-17 or NTNH can be substituted for the naturally occurring carbohydrate binding moiety present in a Clostridial toxin. As another non-limiting example, a 102 of 316 WO 2006/101809 PCT/US2006/008956 carbohydrate binding moiety or a -trefoil fold from HA-33, HA-17 or NTNH can be added in addition to the naturally occurring carbohydrate binding moiety present in a Clostridial toxin. As yet another non limiting example, a multiple carbohydrate binding moieties or a B-trefoil folds from HA-33, HA-17 or NTNH can be substituted for the naturally occurring carbohydrate binding moiety present In a Clostridial toxin. As still another non-limiting example, multiple carbohydrate binding moieties or a B-trefoil folds from HA 33, HA-17 or NTNH can be added in addition to the naturally occurring carbohydrate binding moiety present in a Clostridial toxin. As another non-limiting example, multiple carbohydrate binding moieties or a B-trefoll folds from a Clostridial toxin binding domain can be added in addition to the naturally occurring carbohydrate binding moiety present In a Clostridial toxin. Table 6. P-trefoil Domains of Clostridial NTNH Proteins Amino Acid Sequence Region of Carbohydlrate Bindin Moieties Protein SEQ ID NO: a-fold V40 -old tu8/09fld P-hairpin turn . p-hairpin turn y-fold NTNH/A1 23 1050-1097 1098-1110 1111-1138 1139-1148 1149-1194 NTNH/A2 24 1050-1097 1098-1110 1111-1139 1140-1148 1149-1199 NTNH/A3 25 1050-1097 1098-1110 1111-1138 1139-1148 1149-1194 NTNH/B 26 1049-1096 1097-1109 1110-1138 1139-1147 1148-1198 NTNH/C1 27 1049-1096 1097-1109 1110-1138 1139-1147 1148-1197 NTNH/D 28 1049-1096 1097-1109 1110-1138 1139-1147 1148-1197 NTNH/E 29 1014-1061 1062-1074 1075-1103 1104-1113 1114-1163 NTNH/F1 30 1016-1063 1064-1076 1077-1104 1105-1114 1115-1160 NTNH/F2 31 1017-1064 1065-1077 1078-1106 1107-1116 1117-1166 NTNH/G 32 1050-1097 1098-1110 1111-1139 1140-1149 1150-1199 [0245] As used herein, the term "Non-toxin Associated Protein" is synonymous with "NAP" and means a Clostridial NAP with selective binding activity, such as, e.g., a binding affinity or a binding specificity, for an endogenous Clostridial toxin receptor system. it is envisioned that both naturally occurring NAPs as well as NAPs with enhanced binding activity can be used to practice aspects of the present invention. As used herein, the term "NAP with enhanced binding activity" means a Clostridial NAP with enhanced binding activity for an endogenous Clostridial toxin receptor system, such as, e.g., a binding affinity or a binding specificity, to a statistically significantly degree relative to an unmodified naturally occurring Clostridial toxin binding domain from a Clostridial toxin. By definition, a NAP with enhanced binding activity has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 3-6) and can be described in percent identity to the corresponding region of that reference sequence. [0246] Any of a variety of sequence alignment methods can be used to determine percent identity of a modified Clostridial NAP relative to a naturally-occurring Clostridial NAP, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols 103 of 316 WO 2006/101809 PCT/US2006/008956 to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein. [0247] Approaches well known to one skilled in the art on how to modify a Clostridial NAP In order to increase its binding activity for an endogenous Clostridial toxin receptor system present on a naturally occurring Clostridial toxin target cell. As described above, one approach involves identifying amino acids using computational protein design algorithms; changing specifically-identified amino acids using, without limitation, site-directed mutagenesis, oligonucleotide-directed mutagenesis and site-specific mutagenesis; and testing the binding activity of modified Clostridial toxins comprising a modified Clostridial NAP with enhanced binding activity using, e.g., heterogeneous assays, homogeneous assays and non-separating homogeneous assays. It is further envisioned that the binding activity of a modified Clostridial toxin with enhanced binding activity disclosed in the present specification can be determined by affinity chromotography using immobilized receptors and interfacial optical assays. In another approach described above, a binding activity of a modified Clostridial NAP for a naturally-occurring Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell can be achieved using directed-evolution methods. [0248] A Clostridial NAP includes, without limitation, naturally occurring Clostridial NAP variants, such as, e.g., Clostridial NAP isoforms and Clostridial NAP subtypes; non-naturally occurring Clostridial NAP variants, such as, e.g., conservative Clostridial NAP variants, non-conservative Clostridial NAP variants, Clostridial NAP chimerics, active Clostridial NAP fragments thereof, or any combination thereof. [0249] As used herein, the term "Clostridial NAP variant," whether naturally-occurring or non-naturally occurring, means a Clostridial NAP that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Tables 3-6) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial NAP variants disclosed In the present specification are capable of executing the cell binding step of the intoxication process. [0250] It is recognized by those of skill in the art that within each Clostridial bacterium there can be naturally occurring Clostridial NAP variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently five Clostridial botulinum serotype A HA-33 variants, HA-33/A1, HA-33/A2, HA-33/A3, HA-33/A4 and HA-33/A5 (Tables 3 and 4), with specific HA-33 variants showing various degrees of amino acid divergence when compared to another HA-33 variant. As another example, there are presently three Clostridial botulinum serotype A NTNH-33 variants, NTNH/A1, NTNH/A2 and NTNH/A3 (Table 6), with specific NTNH variant showing various degrees of amino acid divergence when compared to another NTNH variant. As used herein, the term "naturally occurring Clostridial NAP variant" means any Clostridial NAP produced by a naturally occurring process, Including, without limitation, Clostridial NAP Isoforms produced from alternatively 104 of 316 WO 2006/101809 PCT/US2006/008956 spliced transcripts, Clostridial NAP isoforms produced by spontaneous mutation and Clostridial NAP subtypes. A naturally occurring Clostridial NAP variant can function in substantially the same manner as the reference Clostridial NAP on which the naturally occurring Clostridial NAP variant is based, and can be substituted for the reference Clostridial NAP in any aspect of the present invention. A naturally occurring Clostridial NAP variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial NAP on which the naturally occurring Clostridial NAP variant is based. A naturally occurring Clostridial NAP variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial NAP on which the naturally occurring Clostridial NAP variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial NAP on which the naturally occurring Clostridial NAP variant Is based. (0251] A non-limiting examples of a naturally occurring Clostridial NAP variant is a Clostridial NAP isoform such as, e.g., a Clostridial botulinum serotype A HA-33 isoform, a Clostridial botulinum serotype B HA-33 isoform, a Clostridial botulinum serotype C1 HA-33 isoform, a Ciostridial botulinum serotype D HA 33 isoform, a Clostridial botulinum serotype A HA-17 isoform, a Clostridial botulinum serotype B HA-17 isoform, a Clostridial botulinum serotype C1 HA-17 isoform, a Clostridial botulinum serotype D HA-17 isoform, a Clostridial botulinum serotype A NTNH isoform, a Clostridial botulinum serotype B NTNH isoform, a Clostridial botulinum serotype C1 NTNH isoform, a Clostridial botulinum serotype D NTNH isoform, a Clostridial botulinum serotype E NTNH isoform, a Clostridial botulinum serotype F NTNH isoform and a Clostridial botulinum serotype G NTNH isoform. A Clostridial NAP isotorm can function in substantially the same manner as the reference Clostridial NAP on which the Clostridial NAP isoform is based, and can be substituted for the reference Clostridial NAP in any aspect of the present invention. [0252] Another non-limiting examples of a naturally occurring Clostridial NAP variant is a Clostridial NAP subtype such as, e.g., a Clostridial botulinum serotype A HA-33 subtype, a Clostridial botulinum serotype B HA-33 subtype, a Clostridial botulinum serotype C1 HA-33 subtype, a Clostridial botulinum serotype 0 HA-33 subtype, a Clostridial botulinum serotype A HA-17 subtype, a Clostridial botulinum serotype B HA 17 subtype, a Clostridial botulinum serotype C1 HA-17 subtype, a Clostridial botulinum serotype D HA-17 subtype, a Clostridial botulinum serotype A NTNH subtype, a Clostridial botulinum serotype B NTNH subtype, a Clostridial botulinum serotype C1 NTNH subtype, a Clostridial botulinum serotype D NTNH subtype, a Clostridial botulinum serotype E NTNH subtype, a Clostridial botulinum serotype F NTNH subtype and a Clostridial botulinum serotype G NTNH subtype. A Clostridial NAP subtype can function in substantially the same manner as the reference Clostridial NAP on which the Clostridial NAP subtype is based, and can be substituted for the reference Clostridial NAP in any aspect of the present invention. 105 of 316 WO 2006/101809 PCT/US2006/008956 [0253] As used herein, the term "non-naturally occurring Clostridial NAP variant" means any Clostridial NAP produced with the aid of human manipulation, including, without limitation, Clostridial NAPs produced by genetic engineering using random mutagenesis or rational design and Clostridial NAPs produced by chemical synthesis. Non-limiting examples of non-naturally occurring Clostridial NAP variants Include, e.g., conservative Clostridial NAP variants, non-conservative Clostridial NAP variants, Clostridial NAP chimeric variants and active Clostridial NAP fragments. (0254] As used herein, the term "conservative Clostridial NAP variant" means a Clostridial NAP that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial NAP sequence (see Tables 3-6). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial NAP variant can function in substantially the same manner as the reference Clostridial NAP on which the conservative Clostridial NAP variant Is based, and can be substituted for the reference Clostridial NAP in any aspect of the present invention. A conservative Clostridial NAP variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids or 50 or more amino acids from the reference Clostridial NAP on which the conservative Ciostridial NAP variant is based. A conservative Clostridial NAP variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial NAP on which the conservative Clostridial NAP variant is based, that possess at least 50% amino acid Identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid Identity to the reference Clostridial NAP on which the conservative Clostridial NAP variant is based. Non-limiting examples of a conservative Clostridial NAP variant include, e.g., a conservative Clostridial botulinum serotype A HA-33 variant, a conservative Clostridial botulinum serotype B HA-33 variant, a conservative Clostridial botulinum serotype C1 HA-33 variant, a conservative Clostridlal botulinum serotype D HA-33 variant, a conservative Clostridial botulinum serotype A HA-17 variant, a conservative Clostridial botulinum serotype B HA-17 variant, a conservative Clostridial botulinum serotype C1 HA-17 variant, a conservative Clostridial botulinum serotype D HA-17 variant, a conservative Clostridial botulinum serotype A NTNH variant, a conservative Clostridial botulinum serotype B NTNH variant, a conservative Clostridial botulinum serotype C1 NTNH variant, a conservative Clostridial botulinum serotype D NTNH variant, a conservative Clostridial botulinum serotype E NTNH variant, a conservative Clostridial botulinum serotype F NTNH variant and a conservative Clostridial botulinum serotype G NTNH variant. [0255] As used herein, the term "non-conservative Clostridial NAP variant" means a Clostridial NAP in which 1) at least one amino acid is deleted from the reference Clostridial NAP on which the non conservative Clostridial NAP variant Is based; 2) at least one amino acid added to the reference 106 of 316 WO 2006/101809 PCT/US2006/008956 Clostridial NAP on which the non-conservative Clostridial NAP is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial NAP sequence (see Tables 3-6). A non conservative Clostridial NAP variant can function in substantially the same manner as the reference Clostridial NAP on which the non-conservative Clostridial NAP variant is based, and can be substituted for the reference Clostridial NAP in any aspect of the present invention. A non-conservative Clostridial NAP variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial NAP on which the non-conservative Clostridial NAP variant is based. A non-conservative Clostridial NAP variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial NAP on which the non-conservative Clostridial NAP variant is based. A non-conservative Clostridiai NAP variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids or 50 or more amino acids from the reference Clostridial NAP on which the non-conservative Clostridial NAP variant is based. A non conservative Clostridial NAP variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial NAP on which the non-conservative Clostridial NAP variant Is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial NAP on which the non-conservative Clostridial NAP variant is based. Non-limiting examples of a non-conservative Clostridial NAP variant include, e.g., a non-conservative Clostridial botulinum serotype A HA-33 variant, a non-conservative Clostridial botulinum serotype B HA-33 variant, a non-conservative Clostridial botulinum serotype C1 HA 33 variant, a non-conservative Clostridial botulinum serotype D HA-33 variant, a non-conservative Clostridial botulinum serotype A HA-17 variant, a non-conservative Clostridial botulinum serotype B HA 17 variant, a non-conservative Clostridial botulinum serotype C1 HA-17 variant, a non-conservative Clostridial botulinum serotype D HA-17 variant, a non-conservative Clostridial botulinum serotype A NTNH variant, a non-conservative Clostridial botulinum serotype B NTNH variant, a non-conservative Clostridial botulinum serotype C1 NTNH variant, a non-conservative Clostridial botulinum serotype D NTNH variant, a non-conservative Clostridial botulinum serotype E NTNH variant, a non-conservative Clostridial botulinum serotype F NTNH variant and a non-conservative Clostridial botulinum serotype G NTNH variant. [0256] As used herein, the term "Clostridial NAP chimeric" means a polypeptide comprising at least a portion of a Clostridial NAP and at least a portion of at least one other polypeptide to form an enhanced targeting domain with at least one property different from the reference Clostridial NAP (see Tables 3-6), with the proviso that this Clostridial NAP chimeric can specifically bind to a Clostridial toxin receptor 107 of 316 WO 2006/101809 PCT/US2006/008956 system present in a Clostridial toxin target cell, and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. [0257] As used herein, the term "active Clostridial NAP fragment" means any of a variety of Clostridial NAP fragments comprising the enhanced targeting domain can be useful In aspects of the present invention with the proviso that these NAP fragments can specifically bind to a Clostridial toxin receptor system present in a Clostridial toxin target cell, and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. [0258] Thus, In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain derived from a NAP. In another embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain with enhanced binding activity derived from a NAP. [0259] In another embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain derived from a Clostridial HA-33. In an aspect of this embodiment, a B-trefoil domain derived from a Clostridial HA-33 comprises, e.g., a B trefoil domain derived from a Clostridial botulinum serotype A HA-33, a B-trefoil domain derived from a Clostridlal botulinum serotype B HA-33, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 or a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial HA-33 comprises a 1a-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype A HA-33, a 10-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a p-trefoIl domain of a Clostridial botulinum serotype A HA-33, a 20 fold motif of a P-trefol domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33. [0260] In another embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-33. In an aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-33 comprises, e.g., a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 or a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-33 comprises a modified 1a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 11P fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified ly-fold motif of a p trefoil domain of a Clostridlal botulinum serotype A HA-33, a modified 2g-fold motif of a p-trefoll domain of 108 of 316 WO 2006/101809 PCT/US2006/008956 a Clostridial botulinum serotype A HA-33, a modified 20-fold motif of a -trefoil domain of a Clostridial botulinum serotype A HA-33, or a modified 2y-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A HA-33. [0261] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a -trefoil domain derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 9. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 9. In another aspect of this embodiment, a 3 trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 1a-fold motif of a 1 trefoil domain of a Clostridial botulinum serotype A HA-33, a 10-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2p fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 9. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. [0262] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 9. In another embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 9. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified la-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 10-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA 33, a modified 1y-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 20-fold motif of a 1-trefoil domain of a Clostridlal botulinum serotype A HA-33, or a modified 2y-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 9. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. [0263] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at least 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200 109 of 316 WO 2006/101809 PCT/US2006/008956 242, or amino acids 249-293 of SEQ ID NO: 9, at least 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at least 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at least 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105 144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at most 75% amino acid identity with amino acids 10-54, amino acids 60 100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at most 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105 144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at most 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9, at most 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. [0264] In other aspects of this embodiment, a Ciostridlal botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. in other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or 110 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 249-293 of SEQ ID NO: 9. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 1-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. [0265] in other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 1-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200 242, or amino acids 249-293 of SEQ ID NO: 9. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a (-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 9. 111 of 316 WO 2006/101809 PCT/US2006/008956 [0266] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 104/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 108/p9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a 208/P9 hairpin turn of a p-trefoil domain of a Clostridlal botulinum serotype A HA-33 of SEQ ID NO: 9. In another aspect of this embodiment, a B-trefoll domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. [0267] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modifeld 104/s5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modifeld 168/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modifeid 2p4/p5 hairpin turn of a p-trefoil domain of a Clostridlal botulinum serotype A HA-33 or a modifeid 208/p9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 9. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modification of amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. [0268] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at least 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at least 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at least 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at least 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9 or at least 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at most 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at most 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at most 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9, at most 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9 or at most 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. 112 of 316 WO 2006/101809 PCTIUS2006/008956 [0269] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a noncontiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101 104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 9. [0270] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid 113 of 316 WO 2006/101809 PCT/US2006/008956 substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 9 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 9. [0271] In another embodiment, a B-trefoll domain derived from a Clostridial botulinum serotype A HA-33 comprises a A-trefoil domain derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 10. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a la-fold motif of a 1 trefoil domain of a Clostridial botulinum serotype A HA-33, a 10-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 1y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a -trefoil domain of a Clostridial botulinum serotype A HA-33, a 20 fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. [0272] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 10. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified la-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 1 0-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A HA 114 of 316 WO 2006/101809 PCT/US2006/008956 33, a modified ly-fold motif of a 0-trefoll domain of a Clostridial botulinum serotype A HA-33, a modified 2a-fold motif of a 0-trefol domain of a Clostridial botulinum serotype A HA-33, a modified 20-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another aspect of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. [0273] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at least 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200 242, or amino acids 249-293 of SEQ ID NO: 10, at least 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at least 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at least 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105 144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at most 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at most 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at most 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10, at most 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. [0274] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or 115 of 316 WO 2006/101809 PCTIUS2006/008956 amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, tour, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 3-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. [0275] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 0 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Ciostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, 116 of 316 WO 2006/101809 PCTIUS2006/008956 five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. In other aspects of this embodiment, a Ciostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 10. [0276] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 104/P5 hairpin turn of a s-trefoil domain of a Clostridial botulinum serotype A HA-33, a 11P8/09 hairpin tum of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a 208/09 hairpin turn of a S-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. [0277] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified 104/P5 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 1 P8/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a modified 208/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 10. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modification of amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. [0278] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at least 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at least 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at least 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at least 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10 or at least 95% amino 117 of 316 WO 2006/101809 PCT/US2006/008956 acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In yet other aspects of this embodiment, a. B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at most 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at most 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at most 85% amino acid Identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10, at most 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10 or at most 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. [02791 In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. in still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non 118 of 316 WO 2006/101809 PCTIUS2006/008956 contiguous amino acia aaamons relative to amino acids bb-bu, amino acias u i- iu4, amino acias i!oD 199, or amino acids 243-248 of SEQ ID NO: 10. [0280] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 10 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 10. [0281] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a la-fold motif of a P trefoil domain of a Clostridial botulinum serotype A HA-33, a 1p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a ly-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 20 fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a p-trefoil 119 of 316 WO 2006/101809 PCT/US2006/008956 domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. [0282] In another embodiment, a B-trefol domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified la-fold motif of a R-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 1 -fold motif of a s-trefoil domain of a Clostridial botulinum serotype A HA 33, a modified ly-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 2a-fold motif of a p-trefoil domain of a Ciostridlal botulinum serotype A HA-33, a modified 20-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. [0283] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at least 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200 242, or amino acids 249-293 of SEQ ID NO: 11, at least 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at least 85% amino acid Identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at least 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105 144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at most 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of 120 of 316 WO 2006/101809 PCT/US2006/008956 SEQ ID NO: 11, at most 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at most 85% amino acid Identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11, at most 90% amino acid Identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. [0284] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. [0285] in other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, 121 of 316 WO 2006/101809 PCT/US2006/008956 three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 11. [0286] In another embodiment, a S-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 1 4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 108/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 204/p5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a 2P8/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. [0287] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified 1 P4/P5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 10P8/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 204/P5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a modified 208/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 11. In another aspect of this embodiment, a B-trefoil domain with 122 of 316 WO 2006/101809 PCT/US2006/008956 enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modification of amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. [0288] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at least 75% amino acid Identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at least 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at least 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at least 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11 or at least 95% amino acid identity with amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at most 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at most 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at most 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11, at most 90% amino acid identity with amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11 or at most 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. [0289] in other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11 can be replaced with phenylalanine. in yet other aspects of this embodiment, a B-trefoil domain with enhanced 123 of 316 WO 2006/101809 PCT/US2006/008956 binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 11. [0290] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 11 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 11. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, 124 of 316 WO 2006/101809 PCT/US2006/008956 e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ.ID NO: 11. [0291] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 12. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-146 or amino acids 153-294 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 1a-fold motif of a p trefoil domain of a Clostridial botulinum serotype A HA-33, a 1P-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a ly-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2p fold motif of a A-trefoil domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. [0292] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlial botulinum serotype A HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 12. In another embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-146 or amino acids 153-294 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified la-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 10-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A HA 33, a modified ly-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 20-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. [0293] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at least 75% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202 243, or amino acids 250-294 of SEQ ID NO: 12, at least 80% amino acid identity with amino acids 10-56, 125 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at least 85% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at least 90% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107 146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12 or at least 95% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at most 75% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at most 80% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at most 85% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12, at most 90% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12 or at most 95% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. [0294] in other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 1 07-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In still other aspects of this embodiment, a Clostridial botulinum 126 of 316 WO 2006/101809 PCT/US2006/008956 serotype A HA-33 comprising a B-tretoil domain with enhanced binding activity composes a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153 197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. [0295] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153 197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 202-243, or amino acids 250-294 of SEQ ID NO: 12. [0296] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 1P4/05 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33, a 127 of 316 WO 2006/101809 PCT/US2006/008956 118/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2p4/135 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-33 or a 2P8/9 hairpin turn of a p-trefoil domain of a Clostridlal botulinum serotype A HA-33 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. [0297] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified 104/35 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 108/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 or a modified 208/09 hairpin turn of a 1-trefoil domain of a Clostridlal botulinum serotype A HA-33 of SEQ ID NO: 12. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modification of amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. [0298] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at least 75% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at least 80% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at least 85% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at least 90% amino acid Identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12 or at least 95% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at most 75% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at most 80% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at most 85% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12, at most 90% amino acid Identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12 or at most 95% amino acid identity with amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. 128 of 316 WO 2006/101809 PCT/US2006/008956 [0299] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 57-61, amino acids 103-106, amino acids 198 201, or amino acids 244-249 of SEQ ID NO: 12. [0300] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 57-61, amino acids 103-106, amino acids 198 129 of 316 WO 2006/101809 PCT/US2006/008956 201, or amino acids 244-249 of SEQ ID NO: 12 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In still other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 57-61, amino acids 103-106, amino acids 198-201, or amino acids 244-249 of SEQ ID NO: 12. [0301] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a la-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype A HA-33, a 1 p-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 23 fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, or a 2y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 13. [0302] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 10-144 or amino acids 151-293 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified 1 a-fold motif of a s-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 1 P-fold motif of a P-trefoll domain of a Clostridial botulinum serotype A HA 33, a modified 1y-fold motif of a s-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 130 of 316 WO 2006/101809 PCT/US2006/008956 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 20-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial botulinum serotype A HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-242, or amino acids 249-293 of SEQ ID NO: 13. [0303] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at least 75% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198 245, or amino acids 246-279 of SEQ ID NO: 13, at least 80% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at least 85% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at least 90% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103 144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13 or at least 95% amino acid Identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at most 75% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at most 80% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at most 85% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13, at most 90% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151 197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13 or at most 95% amino acid identity with amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. [0304] in other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum 131 of 316 WO 2006/101809 PCT/US2006/008956 serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151 197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. [0305] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151 197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-55, 132 of 316 WO 2006/101809 PCTIUS2006/008956 amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-55, amino acids 56-102, amino acids 103-144, amino acids 151-197, amino acids 198-245, or amino acids 246-279 of SEQ ID NO: 13. [0306] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises a 1P4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a 108/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a 2P4/05 hairpin turn of a -trefoil domain of a Clostridial botulinum serotype A HA-33 or a 2138/09 hairpin turn of a s-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-33 comprises amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. (0307] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modified 1134/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 1138/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33, a modified 2p4/5 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33 or a modified 208/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype A HA-33 of SEQ ID NO: 13. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a modification of amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. [0308] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at least 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at least 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at least 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at least 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13 or at least 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 133 of 316 WO 2006/101809 PCT/US2006/008956 of SEQ ID NO: 13. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at most 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at most 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at most 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13, at most 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13 or at most 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. (0309] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. in other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 13. 134 of 316 WO 2006/101809 PCTIUS2006/008956 [0310] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 243-248 of SEQ ID NO: 13 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101 -104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. In other aspects of this embodiment, a B-trefoil domain with enhanced binding actMty derived from a Clostridial botulinum serotype A HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 243-248 of SEQ ID NO: 13. [0311] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises amino acids 10-144 or amino acids 151-292 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises a 1a-fold motif of a S trefoil domain of a Clostridial botulinum serotype B HA-33, a 10-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a ly-foid motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a 20 fold motif of a p-trefoil domain of a Clostridial botulinum serotype B HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises amino 135 of 316 WO 2006/101809 PCT/US2006/008956 acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. [0312] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises amino acids 10-144 or amino acids 151-292 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a modified 1a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 1 P-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype B HA 33, a modified 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 23-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype B HA-33 comprises amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. [0313] in other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at least 75% amino acid Identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200 241, or amino acids 248-292 of SEQ ID NO: 14, at least 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at least 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at least 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105 144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at most 75% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at most 80% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at 136 of 316 WO 2006/101809 PCT/US2006/008956 most 85% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14, at most 90% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. [0314] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a 8 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In still other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. [0315] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or 137 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151 195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In still other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-100, amino acids 105-144, amino acids 151-195, amino acids 200-241, or amino acids 248-292 of SEQ ID NO: 14. [0316] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises a 104/P5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33, a 1$8/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33, a 2p4/p5 hairpin tum of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 or a 2P8/09 hairpin tum of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. [0317] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a modified 1 P4/p5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 1P8/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 2p4/P5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 or a modified 2P8/p9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 14. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a modification 138 of 316 WO 2006/101809 PCT/US2006/008956 of amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. [0318] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at least 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at least 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at least 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at least 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14 or at least 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at most 75% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at most 80% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at most 85% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14, at most 90% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14 or at most 95% amino acid identity with amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. [0319] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, 139 of 316 WO 2006/101809 PCT/US2006/008956 e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 242-247 of SEQ ID NO: 14. (0320] In other aspects of this embodiment, a 0-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 101-104, amino acids 196 199, or amino acids 242-247 of SEQ ID NO: 14 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a 0-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, 140 of 316 WO 2006/101809 PCTIUS2006/008956 e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 101-104, amino acids 196-199, or amino acids 242-247 of SEQ ID NO: 14. [0321] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 15. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. [0322] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at least 75% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200 242, or amino acids 249-291 of SEQ ID NO: 15, at least 80% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at least 85% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at least 90% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107 146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15 or at least 95% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at most 75% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at most 80% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at most 85% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15, at most 90% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15 or at most 95% amino acid identity with amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. [0323] In other aspects of this embodiment, a Clostridia botulinum serotype B HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, 141 of 316 WO 2006/101809 PCT/US2006/008956 three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In still other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153 197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. [0324] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a (3 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153 197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In yet other aspects of this embodiment, a Ciostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. 142 of 316 WO 2006/101809 PCT/US2006/008956 In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In still other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-56, amino acids 62-102, amino acids 107-146, amino acids 153-197, amino acids 200-242, or amino acids 249-291 of SEQ ID NO: 15. [0325] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises a 104/P5 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype B HA-33, a 108/09 hairpin turn of a -trefoil domain of a Clostridial botulinum serotype B HA-33, a 204/R5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 or a 208/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 15. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-33 comprises amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. [0326] In another embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a modified 104/05 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 1138/@9 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype B HA-33, a modified 24/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype B HA-33 or a modified 208/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype B HA-33 of SEQ ID NO: 15. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a modification of amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. [0327] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at least 75% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at least 80% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at least 85% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or 143 of 316 WO 2006/101809 PCTIUS2006/008956 amino acids 243-248 of SEQ ID NO: 15, at least 90% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15 or at least 95% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at most 75% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at most 80% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at most 85% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15, at most 90% amino acid identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15 or at most 95% amino acid Identity with amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ iD NO: 15. [0328] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino -acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. in other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridia 144 of 316 WO 2006/101809 PCT/US2006/008956 botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 56-61, amino acids 103-106, amino acids 198 201, or amino acids 243-248 of SEQ ID NO: 15. [0329] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 56-61, amino acids 103-106, amino acids 198 201, or amino acids 243-248 of SEQ ID NO: 15 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. In other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 56-61, amino acids 103-106, amino acids 198-201, or amino acids 243-248 of SEQ ID NO: 15. [0330] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-141 or amino acids 148-285 of SEQ ID NO: 16. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises a la fold motif of a -trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 1 p-fold motif of a p-trefoii domain of a Clostridial botulinum serotype C1 HA-33, a 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 145 of 316 WO 2006/101809 PCTIUS2006/008956 HA-33, a 2p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, or a 2y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. [0331] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype C1 HA-33 comprises amino acids 10-141 or amino acids 148-285 of SEQ ID NO: 16. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a modified la-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 1 p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified ly-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 2a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 2p fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, or a modified 2y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. [0332] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at least 75% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at least 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at least 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at least 90% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at most 75% amino acid identity with amino acids 10-54, amino acids 146 of 316 WO 2006/101809 PCT/US2006/008956 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at most 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at most 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16, at most 90% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. [0333] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. in other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. 147 of 316 WO 2006/101809 PCT/US2006/008956 [0334] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In still other aspects of this embodiment, a Clostridial botulinum serotype Cl HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-234, or amino acids 241-285 of SEQ ID NO: 16. [0335] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 33 comprises a 104/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 1p8/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 2p4/p5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 or a 208/P9 hairpin turn of a p trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. [0336] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botullnum serotype C1 HA-33 comprises a modified M4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 or a modified 114/P5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 1 P8/09 hairpin turn of a p-trefoil domain of a 148 of 316 WO 2006/101809 PCT/US2006/008956 Clostridial botulinum serotype C1 HA-33, a modified 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 or a modified 2P8/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 16. In another aspect of this embodiment, a (3 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a modification of amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. [0337] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at least 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at least 80% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at least 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at least 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 or at least 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at most 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at most 80% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at most 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16, at most 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 or at most 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. [0338] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 can be replaced with glycine. In other aspects of this 149 of 316 WO 2006/101809 PCT/US2006/008956 embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. [0339] in other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous 150 of 316 WO 2006/101809 PCT/US2006/008956 amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 235-240 of SEQ ID NO: 16. [0340] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 33 comprises a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. In another embodiment, a 8-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-141 or amino acids 148-286 of SEQ ID NO: 17. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises a 1a fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 1 0-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 20-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, or a 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridlal botulinum serotype C1 HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. [0341] In another embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. In another embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-141 or amino acids 148-286 of SEQ ID NO: 17. In another aspect of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a modified la-fold motif of a S-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 1@-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 1y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 2a-fold motif of a 0-trefol domain of a Clostridial botulinum serotype C1 HA-33, a modified 2p fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. [0342] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, 151 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at least 75% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at least 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at least 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at least 90% amino acid Identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at most 75% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at most 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at most 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17, at most 90% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. [0343] In other aspects of this embodiment, a Clostridlal botulinum serotype C1 HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, 152 of 316 WO 2006/101809 PCT/US2006/008956 three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. [0344] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 17. 153 of 316 WO 2006/101809 PCT/US2006/008956 [0345] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 33 comprises a 104/05 hairpin turn of a 0-trefol domain of a Clostridial botulinum serotype C1 HA-33, a 108/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a 204/05 hairpin turn of a f-trefoil domain of a Clostridial botulinum serotype C1 HA-33 or a 238/39 hairpin tum of a p trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-33 comprises amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. [0346] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a modified 1104/P5 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 138/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype C1 HA-33, a modified 204/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-33 or a modified 208/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype C1 HA-33 of SEQ ID NO: 17. in another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a modification of amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. [0347] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at least 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at least 80% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at least 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at least 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 or at least 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at most 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at most 80% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at most 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17, at most 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 or at 154 of 316 WO 2006/101809 PCTIUS2006/008956 most 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. [0348] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. in other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. in other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 can be replaced with phenylalanine. in yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. [0349] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from 155 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 17. [0350] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprise, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprises amino acids 10-141 or amino acids 148-286 of SEQ ID NO: 18. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprises a la-fold motif of a 1 trefoil domain of a Clostridial botulinum serotype D HA-33, a 1p-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA-33, a 1y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-33, a 2a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA-33, a 20 fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA-33, or a 2y-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. [0351] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises amino acids 10-141 or amino acids 148-286 of SEQ ID NO: 18. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum 156 of 316 WO 2006/101809 PCTiUS2006/008956 serotype D HA-33 comprises a modified 1a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA-33, a modified 11-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA 33, a modified 1y-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype D HA-33, a modified 2a-fold motif of a -trefoil domain of a Ciostridial botulinum serotype D HA-33, a modified 20-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-33, or a modified 2y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. [0352] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at least 75% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at least 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at least 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at least 90% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18 or at least 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In yet other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at most 75% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at most 80% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103 141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at most 85% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18, at most 90% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18 or at most 95% amino acid identity with amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. [0353] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a 3 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, 157 of 316 WO 2006/101809 PCT/US2006/008956 three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In yet other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In still other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. [0354] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a a trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148 190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In yet other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a a-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. 158 of 316 WO 2006/101809 PCT/US2006/008956 In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In still other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-33 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 10-54, amino acids 60-98, amino acids 103-141, amino acids 148-190, amino acids 195-235, or amino acids 242-286 of SEQ ID NO: 18. [0355] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprises a 1134/p5 hairpin turn of a s-trefoil domain of a Clostridial botulinum serotype D HA-33, a 108/09 hairpin turn of a S-trefoil domain of a Clostridial botulinum serotype D HA-33, a 204/35 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype D HA-33 or a 2p8/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-33 comprises amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. [0356] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botullnum serotype D HA-33 comprises a modified 104/P5 hairpin tum of a p-trefoil domain of a Clostridial botulinum serotype D HA-33, a modified 108/09 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype D HA-33, a modified 204/05 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype D HA-33 or a modified 218/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype D HA-33 of SEQ ID NO: 18. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a modification of amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. [0357] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at least 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at least 80% amino acid Identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at least 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or 159 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 236-241 of SEQ ID NO: 18, at least 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 or at least 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at most 75% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at most 80% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at most 85% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18, at most 90% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 or at most 95% amino acid identity with amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. [0358] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194; or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial 160 of 316 WO 2006/101809 PCT/US2006/008956 botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four non contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. [0359] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-33 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 55-59, amino acids 99-102, amino acids 191-194, or amino acids 236-241 of SEQ ID NO: 18. [0360] In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain derived from a Clostridial HA-17. In an aspect of this embodiment, a B-trefoil domain derived from a Clostridial HA-17 comprises, e.g., a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-1 7, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-1 7 or a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial HA-1 7 comprises a a-fold motif of a P-trefoil 161 of 316 WO 2006/101809 PCT/US2006/008956 domain of a Clostridial HA-17, a 1-fold motif of a p-trefoil domain of a Clostridial HA-17 or a y-fold motif of a P-trefoil domain of a Clostridial HA-17. [0361] In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-17. In an aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-17 comprises, e.g., a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 or a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-1 7. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial HA-17 comprises a modified a-fold motif of a P-trefoil domain of a Clostridial HA-17, a modified -fold motif of a 0-trefoil domain of a Clostridial HA 17 or a modified y-fold motif of a P-trefoil domain of a Clostridial HA-17. [0362] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17 comprises a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17 comprises amino acids 9-146 of SEQ ID NO: 19. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17 comprises a a-fold motif of a P-trefoil domain of a Clostridial botulnum serotype A HA-17, a P-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-I7 or a y-fold motif of a R-trefoil domain of a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. [0363] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype A HA-17 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises amino acids 9-146 of SEQ ID NO: 19. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a modified a-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-17, a modified 1-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A HA-17 or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. 162 of 316 WO 2006/101809 PCT/US2006/008956 [0364] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at least 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at least 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at least 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at least 90% amino acid identity with amino acids 9-50, amino acids 55 91, or amino acids 95-146 of SEQ ID NO: 19 or at least 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at most 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at most 80% amino acid Identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at most 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19, at most 90% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19 or at most 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. [0365] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a 13 trefoii domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide 163 of 316 WO 2006/101809 PCTfUS2006/008956 having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. [0366] In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. in other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In yet other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In still other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. In other aspects of this embodiment, a Clostridial botulinum serotype A HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 19. [0367] In another embodiment, a B-trefoil domain derived from a Clostridia botulinum serotype A HA-17 comprises a P4/05 hairpin tum of a P-trefoil domain of a Clostridial botulinum serotype A HA-17 or a 08/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A HA 17 comprises amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. [0368] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a modified p4/05 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-17 or a modified 08/p9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A HA-17 of SEQ ID NO: 19. In another aspect of this embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a modification of amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. 164 of 316 WO 2006/101809 PCT/US2006/008956 [0369] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-1 7 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at least 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at least 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at least 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at least 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ. ID NO: 19 or at least 95% amino acid Identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-1 7 composes a polypeptide having, e.g., at most 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at most 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at most 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at most 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19, at most 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19 or at most 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. [0370] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-1 7 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-1 7 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-1 7 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. 165 of 316 WO 2006/101809 PCTIUS2006/008956 [0371] In other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 19. [0372] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 comprises a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 comprises amino acids 9-146 of SEQ ID NO: 20. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 comprises a a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-17, a 0-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype B HA-17 or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. [0373] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In another embodiment, a B 166 of 316 WO 2006/101809 PCT/US2006/008956 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises amino acids 9-146 of SEQ ID NO: 20. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a modified a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype B HA-17, a modified 0-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype B HA-17 or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In another aspect of this embodiment, a (3-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. [0374] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at least 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at least 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at least 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at least 90% amino acid identity with amino acids 9-50, amino acids 55 91, or amino acids 95-146 of SEQ ID NO: 20 or at least 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at most 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at most 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at most 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20, at most 90% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20 or at most 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. [0375] in other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non 167 of 316 WO 2006/101809 PCT/US2006/008956 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In still other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. [0376] In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In yet other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In still other aspects of this embodiment, a Clostridlal botulinum serotype B HA-17 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. In other aspects of this embodiment, a Clostridial botulinum serotype B HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 20. [0377] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA-17 comprises a P4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype B HA-17 or a P8/09 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In 168 of 316 WO 2006/101809 PCT/US2006/008956 another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B HA 17 comprises amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. [0378] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a modified P4/05 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B HA-17 or a modified 08/P9 hairpin tum of a P-trefoil domain of a Clostridial botulinum serotype B HA-17 of SEQ ID NO: 20. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a modification of amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. [0379] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at least 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at least 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at least 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at least 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 or at least 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-1 7 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at most 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at most 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at most 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20, at most 90% amino acid Identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 or at most 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. [0380] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or 169 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-11 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-1 7 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. [0381] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-1 7 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In still other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 20. [0382] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 17 comprises a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-17 comprises amino acids 9-146 of SEQ ID NO: 21. In another aspect of this embodiment, a B-trefoil 170 of 316 WO 2006/101809 PCT/US2006/008956 domain derived from a Clostridial botulinum serotype C1 HA-17 comprises a a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype C1 HA-17, a p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-17 or a y-fold motif of a a-trefoil domain of a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. [0383] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises amino acids 9-146 of SEQ ID NO: 21. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a modified a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-17, a modified p fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-17 or a modified y-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another aspect of this embodiment, a 6-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. [0384] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at least 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at least 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at least 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at least 90% amino acid identity with amino acids 9-50, amino acids 55 91, or amino acids 95-146 of SEQ ID NO: 21 or at least 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at most 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at most 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at most 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21, at most 90% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21 or at most 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. 171 of 316 WO 2006/101809 PCT/US2006/008956 [0385] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In other aspects of this embodiment, a Clostridial botuiinum serotype C1 HA-17 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In yet other aspects of this embodiment, a Ciostridlal botulinum serotype C1 HA-17 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-1 7 comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO; 21. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contIguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. [0386] In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a 1--trefoil domain with enhanced binding activity 172 of 316 WO 2006/101809 PCT/US2006/008956 comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. In other aspects of this embodiment, a Clostridial botulinum serotype C1 HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 21. [0387] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA 17 comprises a $4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-1 7 or a P8/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 HA-17 comprises amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. [0388] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a modified 4/05 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype C1 HA-17 or a mofified 08/p9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 HA-17 of SEQ ID NO: 21. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a modification of amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. [0389] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlial botulinum serotype C1 HA-1 7 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at least 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at least 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at least 85% amino acid Identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at least 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 or at least 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In yet other aspects of this embodiment, a B-trefol domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at most 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at most 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at most 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21, at most 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 or at most 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. [0390] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 173 of 316 WO 2006/101809 PCT/US2006/008956 of SEQ ID NO: 21. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In still other aspects of this embodiment, a (3 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. [0391] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-1 7 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92 94 of SEQ ID NO: 21. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-1 7 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-1 7 comprises a polypeptide having, 174 of 316 WO 2006/101809 PCT/US2006/008956 e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 21. [0392] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 comprises a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 of SEQ ID NO: 22. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 comprises amino acids 9-146 of SEQ ID NO: 22. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 comprises a a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-17, a p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-17 or a y-fold motif of a p-trefoll domain of a Clostridial botulinum serotype D HA-17 of SEQ ID NO: 22. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. [0393] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype D HA-17 of SEQ ID NO: 22. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises amino acids 9-146 of SEQ ID NO: 22. In another aspect of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a modified a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-17, a modified p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D HA-17 or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype D HA-17 of SEQ ID NO: 22. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. [0394] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at least 75% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at least 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at least 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at least 90% amino acid identity with amino acids 9-50, amino acids 55 91, or amino acids 95-146 of SEQ ID NO: 22 or at least 95% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In yet other aspects of this embodiment, a 175 of 316 WO 2006/101809 PCT/US2006/008956 Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at most 75% amino acid Identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at most 80% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at most 85% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22, at most 90% amino acid identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22 or at most 95% amino acid Identity with amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. [0395] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In yet other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In still other aspects of this embodiment, a Clostridial botullnum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. [0396] In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, 176 of 316 WO 2006/101809 PCT/US2006/008956 nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In yet other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In still other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. In other aspects of this embodiment, a Clostridial botulinum serotype D HA-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 9-50, amino acids 55-91, or amino acids 95-146 of SEQ ID NO: 22. [0397] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA-17 comprises a P4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype D HA-17 or a P8/p9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype D HA-17 of SEQ ID NO: 22. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D HA 17 comprises amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. [0398] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a modified 04/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype D HA-17 or a modified $8/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype D HA-17 of SEQ ID NO: 22. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridia botulinum serotype D HA-17 comprises a modification of amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. [0399] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at least 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at least 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at least 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at least 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 or at least 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a 177 of 316 WO 2006/101809 PCTIUS2006/008956 polypeptide having, e.g., at most 70% amino acid Identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at most 75% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at most 80% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at most 85% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22, at most 90% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 or at most 95% amino acid identity with amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. [04001 In other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In still other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-1 7 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. [0401] In other aspects of this embodiment, a 1-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 can be replaced with glycine. In 178 of 316 WO 2006/101809 PCTIUS2006/008956 other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoll domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In still other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D HA-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 51-54 or amino acids 92-94 of SEQ ID NO: 22. [0402] In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain derived from a Clostridial NTNH. In an aspect of this embodiment, a B-trefoil domain derived from a Clostridial NTNH comprises, e.g., a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH, a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH, a B-trefoil domain derived from a Clostridial botulinum serotype E NTNH, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH or a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial NTNH comprises a a-fold motif of a P-trefoil domain of a Clostridial NTNH, a 0-fold motif of a P-trefoil domain of a Clostridial NTNH or a V-fold motif of a P-trefoil domain of a Clostridial NTNH. [0403] In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain with enhanced binding activity derived from a Clostridial NTNH. In an aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial NTNH comprises, e.g., a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH, a B-trefoli domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH or , a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH. In another aspect of this embodiment, a B-trefoil 179 of 316 WO 2006/101809 PCT/US2006/008956 domain with enhanced binding activity derived from a Clostridial NTNH comprises a modified a-fold motif of a P-trefoil domain of a Clostridial NTNH, a modified 0-fold motif of a -trefoil domain of a Clostridial NTNH or a modified y-fold motif of a R-trefoil domain of a Clostridial NTNH. [0404] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1194 of SEQ ID NO: 23. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a a-fold motif of a -trefoil domain of a Clostridial botulinum serotype A NTNH, a 0-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A NTNH or a y-fold motif of a s-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another aspect of this embodiment, a 13-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. [0405] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1194 of SEQ ID NO: 23. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype A NTNH, a modified p-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A NTNH or a modified y-fold motif of a 1 trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. [0406] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at least 75% amino acid Identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at least 80% amino acid Identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at least 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at least 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23 or at least 95% amino acid identity with amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 23. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a 180 of 316 WO 2006/101809 PCT/US2006/008956 polypeptide having, e.g., at most 70% amino acid identity with amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 23, at most 75% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at most 80% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at most 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23, at most 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23 or at most 95% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. [0407] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In still other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. [0408] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, 181 of 316 WO 2006/101809 PCTIUS2006/008956 seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In still other aspects of this embodiment, a Clostridia botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 23. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 23. [0409] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a 04/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A NTNH or a P8/p9 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. [0410] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified p4/05 hairpin turn of a 0-trefol domain of a Clostridial botulinum serotype A NTNH or a modified 08/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 23. In another aspect of this embodiment, a 8 trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype A NTNH comprises a modification of amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. [0411] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at least 75% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at least 80% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at least 85% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at least 90% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23 or at least 95% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID 182 of 316 WO 2006/101809 PCTIUS2006/008956 NO: 23. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at most 75% amino acid Identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at most 80% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at most 85% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23, at most 90% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23 or at most 95% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. [0412] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098 1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1098-1110 or amino acids 1139 1148 of SEQ ID NO: 23 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. [0413] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139 1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding 183 of 316 WO 2006/101809 PCT/US2006/008956 activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1098 1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botullnum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 23. [0414] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1194 of SEQ ID NO: 24. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A NTNH, a p-fold motif of a -trefoil domain of a Clostridial botulinum serotype A NTNH or a y-fold motif of a 13-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. [0415] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1194 of SEQ ID NO: 24. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype A NTNH, a modified p-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A NTNH or a modified y-fold motif of a p 184 of 316 WO 2006/101809 PCT/US2006/008956 trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. [0416] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at least 75% amino acid Identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at least 80% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at least 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at least 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24 or at least 95% amino acid identity with amino acids 1050-1097, amino acids 1111 1139, or amino acids 1149-1199 of SEQ ID NO: 24. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1050-1097, amino acids 1111 1139, or amino acids 1149-1199 of SEQ ID NO: 24, at most 75% amino acid Identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at most 80% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at most 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24, at most 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24 or at most 95% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. [0417] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 3 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111 1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non 185 of 316 WO 2006/101809 PCT/US2006/008956 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In still other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. [0418] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 13 trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B--trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Ciostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In still other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1149-1199 of SEQ ID NO: 24. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111 1139, or amino acids 1149-1199 of SEQ ID NO: 24. [0419] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a 04/05 hairpin tum of a p-trefoil domain of a Clostridial botulinum serotype A NTNH or a P8/109 hairpin tum of a 1-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. 186 of 316 WO 2006/101809 PCTUS2006/008956 [0420] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified 4/$5 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A NTNH or a modified P8/P9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 24. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modification of amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. [0421] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at least 75% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at least 80% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at least 85% amino acid Identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at least 90% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24 or at least 95% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at most 75% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at most 80% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at most 85% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24, at most 90% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24 or at most 95% amino acid identity with amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. [0422] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098 1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1098-1110 or amino acids 1140 1148 of SEQ ID NO: 24 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous 187 of 316 WO 2006/101809 PCTIUS2006/008956 amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. [0423] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140 1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1098 1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1148 of SEQ ID NO: 24. [0424] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 25. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises 188 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 1050-1194 of SEQ ID NO: 25. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype A NTNH, a 3-fold motif of a S-trefoil domain of a Clostridial botulinum serotype A NTNH or a y-fold motif of a 0-trefoil domain of a Clostridlal botulinum serotype A NTNH of SEQ ID NO: 25. In another aspect of this embodiment, a B-trefoil domain derived from a Ciostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. [0425] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype A NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH of SEQ ID NO: 25. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1194 of SEQ ID NO: 25. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified a-fold motif of a -trefoil domain of a Clostridial botulinum serotype A NTNH, a modified 1-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype A NTNH or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 25. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. [0426] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid Identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at least 75% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at least 80% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at least 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at least 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25 or at least 95% amino acid Identity with amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 25. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 25, at most 75% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at most 80% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at most 85% amino acid Identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25, at most 90% amino acid identity with amino acids 1050-1097, amino 189 of 316 WO 2006/101809 PCT/US2006/008956 acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25 or at most 95% amino acid identity with amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. [0427] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a 8 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In still other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. (0428] In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In yet other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum 190 of 316 WO 2006/101809 PCTiUS2006/008956 serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In still other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1138, or amino acids 1149-1194 of SEQ ID NO: 25. In other aspects of this embodiment, a Clostridial botulinum serotype A NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111 1138, or amino acids 1149-1194 of SEQ ID NO: 25. [0429] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises a 04/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A NTNH or a 08/9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype A NTNH of SEQ ID NO: 25. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype A NTNH comprises amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. [0430] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modified 04/05 hairpin turn of a -trefoil domain of a Clostridlal botullnum serotype A NTNH or a modified 08/09 hairpin turn of a P-trefoil domain of a Ciostridial botulinum serotype A NTNH of SEQ ID NO: 25. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a modification of amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. [0431] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at least 75% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at least 80% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at least 85% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at least 90% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25 or at least 95% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridla botulinum serotype A NTNH comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at most 75% amIno acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at most 80% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25, at most 85% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 191 of 316 WO 2006/101809 PCT/US2006/008956 25, at most 90% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25 or at most 95% amino acid identity with amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. [0432] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098 1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1098-1110 or amino acids 1139 1148 of SEQ ID NO: 25 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. [0433] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139 1148 of SEQ ID NO: 25. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Ciostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25 can 192 of 316 WO 2006/101809 PCT/US2006/008956 be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridlial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1098 1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. In other aspects of this embodiment, a 1-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype A NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1139-1148 of SEQ ID NO: 25. [0434] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises amino acids 1049-1198 of SEQ ID NO: 26. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises a a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype B NTNH, a P-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another aspect of this embodiment, a 13-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. [0435] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises amino acids 1049-1198 of SEQ ID NO: 26. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a modified a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype B NTNH, a modified P-fold motif of a p-trefoil domain of a Clostridial botulinum serotype B NTNH or a modified y-fold motif of a P trefoil domain of a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another aspect of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. 193 of 316 WO 2006/101809 PCT[US2006/008956 [0436] In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at least 75% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at least 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at least 85% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at least 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26 or at least 95% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1198 of SEQ ID NO: 26. In yet other aspects of this embodiment, a Clostridla botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1198 of SEQ ID NO: 26, at most 75% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at most 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at most 85% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26, at most 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26 or at most 95% amino acid Identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. [0437] In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contIguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In yet other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1198 of SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In still other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of 194 of 316 WO 2006/101809 PCT/US2006/008956 SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. [04381 In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In yet other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In still other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1198 of SEQ ID NO: 26. In other aspects of this embodiment, a Clostridial botulinum serotype B NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1198 of SEQ ID NO: 26. [0439] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises a P/p5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B NTNH or a p8/p9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype B NTNH comprises amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. [0440] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a modified 04/05 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype B NTNH or a modified 08/p9 hairpin turn of a P-trefoll domain of a Clostridial botulinum serotype B NTNH of SEQ ID NO: 26. In another aspect of this embodiment, a B 195 of 316 WO 2006/101809 PCT/US2006/008956 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a modification of amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. [0441] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at least 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at least 80% amino acid Identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at least 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at least 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26 or at least 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at most 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at most 80% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at most 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26, at most 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26 or at most 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. [04421 In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1097 1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 26 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding 196 of 316 WO 2006/101809 PCT/US2006/008956 activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a 5-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. [0443] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 26. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1097 1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In still other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype B NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 26. [0444] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH comprises amino acids 1049-1197 of SEQ ID NO: 27. In another aspect of this embodiment, a B trefoil domain derived from a Clostridial botulinum serotype C1 NTNH comprises a a-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype C1 NTNH, a p-fold motif of a p-trefoil domain of a Clostridial botulinum serotype C1 NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another aspect of this embodiment, a B-trefoil domain derived 197 of 316 WO 2006/101809 PCTIUS2006/008956 from a Clostridial botulinum serotype C1 NTNH comprises amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 27. [0445] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises amino acids 1049-1197 of SEQ ID NO: 27. In another aspect of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a modified a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 NTNH, a modified 0 fold motif of a P-trefoil domain of a Clostridial botulinum serotype C1 NTNH or a modified y-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148 1197 of SEQ ID NO: 27. [0446] In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at least 75% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at least 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at least 85% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at least 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27 or at least 95% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 27. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 27, at most 75% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at most 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at most 85% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27, at most 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27 or at most 95% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. [0447] In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino 198 of 316 WO 2006/101809 PCT/US2006/008956 acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. [0448] In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In yet other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In still other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative 199 of 316 WO 2006/101809 PCTIUS2006/008956 to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. In other aspects of this embodiment, a Clostridial botulinum serotype C1 NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 27. [0449] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH comprises a P4/05 hairpin tum of a P-trefoil domain of a Clostridial botulinum serotype C1 NTNH or a P8/p9 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype C1 NTNH comprises amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. [0450] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a modified 04/5 hairpin turn of a 0-trefol domain of a Clostridial botulinum serotype C1 NTNH or a modified P8/p9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype C1 NTNH of SEQ ID NO: 27. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a modification of amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. [0451] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at least 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at least 80% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at least 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at least 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27 or at least 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at most 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at most 80% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at most 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27, at most 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27 or at most 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. [0452] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, 200 of 316 WO 2006/101809 PCT/US2006/008956 three or four non-contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a. B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1097 1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 27 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. [0453] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 27. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions 201 of 316 WO 2006/101809 PCT/US2006/008956 relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype C1 NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 27. [0454] In another embodiment, a B-trefoil domain derived from a Clostridlal botulinum serotype D NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH comprises amino acids 1049-1197 of SEQ ID NO: 28. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH comprises a a-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype D NTNH, a 0-fold motif of a 1-trefoil domain of a Clostridial botulinum serotype D NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH comprises amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. [0455] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises amino acids 1049-1197 of SEQ ID NO: 28. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a modified a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype D NTNH, a modified 1-fold motif of a p-trefoil domain of a Clostridial botulinum serotype D NTNH or a modified y-fold motif of a p trefoil domain of a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. [0456] In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at least 75% amino acid Identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at least 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at least 85% amino acid Identity with 202 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at least 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28 or at least 95% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 28. In yet other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 28, at most 75% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at most 80% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at most 85% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28, at most 90% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28 or at most 95% amino acid identity with amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. [0457] in other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a 3 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In yet other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In still other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. 203 of 316 WO 2006/101809 PCTIUS2006/008956 [0458] In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In yet other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In still other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110-1138, or amino acids 1148-1197 of SEQ ID NO: 28. In other aspects of this embodiment, a Clostridial botulinum serotype D NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1049-1096, amino acids 1110 1138, or amino acids 1148-1197 of SEQ ID NO: 28. [0459] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH comprises a 04/P5 hairpin turn of a -trefoil domain of a Clostridial botulinum serotype D NTNH or a 08/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype D NTNH comprises amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. [0460] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a modified 04/05 hairpin turn of a 1-trefoil domain of a Clostridial botulinum serotype D NTNH or a modified 08/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype D NTNH of SEQ ID NO: 28. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a modification of amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. [0461] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least 70% amino 204 of 316 WO 2006/101809 PCT/US2006/008956 acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at least 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at least 80% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at least 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at least 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28 or at least 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at most 75% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at most 80% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at most 85% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28, at most 90% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28 or at most 95% amino acid identity with amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. [0462] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e-g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1097 1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 28 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype D NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide 205 of 316 WO 2006/101809 PCT/US2006/008956 having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. [0463] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139 1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28 can be replaced with phenylalanine. In yet other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1097 1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype D NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1097-1109 or amino acids 1139-1147 of SEQ ID NO: 28. [0464] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises a B-trefoil domain derived from a Clostridlal botulinum serotype E NTNH of SEQ ID NO: 29. In another embodiment, a (3-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises amino acids 1014-1163 of SEQ ID NO: 29. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises a a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype E NTNH, a 0-fold motif of a P-trefoil domain of a Clostridial botulinum serotype E NTNH or a y-fold motif of a -trefoil domain of a Clostridial botulinum serotype E NTNH of SEQ ID NO: 29. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. 206 of 316 WO 2006/101809 PCT/US2006/008956 [0465] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH of SEQ ID NO: 29. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises amino acids 1014-1163 of SEQ ID NO: 29. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a modified a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype E NTNH, a modified p-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype E NTNH or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype E NTNH of SEQ ID NO: 29. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. [0466] In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at least 75% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at least 80% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at least 85% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at least 90% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29 or at least 95% amino acid identity with amino acids 1014-1061, amino acids 1075 1103, or amino acids 1114-1163 of SEQ ID NO: 29. In yet other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1014-1061, amino acids 1075 1103, or amino acids 1114-1163 of SEQ ID NO: 29, at most 75% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at most 80% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at most 85% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29, at most 90% amino acid identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29 or at most 95% amino acid Identity with amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. [0467] In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, 207 of 316 WO 2006/101809 PCT/US2006/008956 seven, eight, nine, 10 or 20 non-contIguous amino acid substitutions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In yet other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a (3-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1014-1061, amino acids 1075 1103, or amino acids 1114-1163 of SEQ ID NO: 29. in other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a (3-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In still other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. [0468] In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In yet other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In still other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1014-1061, amino acids 1075-1103, or amino acids 1114-1163 of SEQ ID NO: 29. In other aspects of this embodiment, a Clostridial botulinum serotype E NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, 208 of 316 WO 2006/101809 PCT/US2006/008956 nine, 10 or 20 contiguous amino acid additions relative to amino acids 1014-1061, amino acids 1075 1103, or amino acids 1114-1163 of SEQ ID NO: 29. [0469] In another embodiment, a 13-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises a 04/05 hairpin turn of a 0-trefoil domain of a Clostridial botulinum serotype E NTNH or a 08/p9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype E NTNH of SEQ ID NO: 29. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype E NTNH comprises amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. [0470] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a modified $4/P5 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype E NTNH or a modified 08/P9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype E NTNH of SEQ ID NO: 29. In another aspect of this embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a modification of amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. [0471] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at least 75% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at least 80% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at least 85% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at least 90% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29 or at least 95% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at most 75% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at most 80% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at most 85% amino acid Identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29, at most 90% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29 or at most 95% amino acid identity with amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. [0472] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, 209 of 316 WO 2006/101809 PCT/US2006/008956 e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1062 1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1062-1074 or amino acids 1104 1113 of SEQ ID NO: 29 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In still other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. [0473] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1062-1074 or amino acids 1104 1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1062 1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions 210 of 316 WO 2006/101809 PCT/US2006/008956 relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype E NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1062-1074 or amino acids 1104-1113 of SEQ ID NO: 29. [0474] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1016-1160 of SEQ ID NO: 30. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a a-fold motif of a p-trefoil domain of a Clostridial botulinum serotype F NTNH, a 0-fold motif of a p-trefoil domain of a Clostridial botulinum serotype F NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. [0475] In another embodiment, a B-trefoll domain with enhanced binding actity derived from a Clostridial botulinum serotype F NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another embodiment, a 13 trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1016-1160 of SEQ ID NO: 30. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modified a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype F NTNH, a modified 3-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype F NTNH or a modified y-fold motif of a 0 trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. [0476] In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at least 75% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at least 80% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at least 85% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at least 90% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30 or at least 95% amino acid identity with amino acids 1016-1063, amino acids 1077 1104, or amino acids 1115-1160 of SEQ ID NO: 30. In yet other aspects of this embodiment, a Clostridial 211 of 316 WO 2006/101809 PCT/US2006/008956 botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1016-1063, amino acids 1077 1104, or amino acids 1115-1160 of SEQ ID NO: 30, at most 75% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at most 80% amino acid Identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at most 85% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30, at most 90% amino acid identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30 or at most 95% amino acid Identity with amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. [0477] In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In yet other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In still other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1016 1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. [0478] In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced 212 of 316 WO 2006/101809 PCT/US2006/008956 binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1016-1063, amino acids 1077 1104, or amino acids 1115-1160 of SEQ ID NO: 30. In yet other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115 1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoli domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In still other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1016-1063, amino acids 1077-1104, or amino acids 1115-1160 of SEQ ID NO: 30. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1016-1063, amino acids 1077 1104, or amino acids 1115-1160 of SEQ ID NO: 30. [0479] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a P4/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype F NTNH or a p8/09 hairpin turn of a -trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another aspect of this embodiment, a 0-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. [0480] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modified 04/05 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype F NTNH or a modified 08/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 30. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modification of amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. [0481] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at least 75% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at least 80% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at least 85% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at least 90% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 213 of 316 WO 2006/101809 PCT/US2006/008956 30 or at least 95% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at most 75% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at most 80% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at most 85% amino acid Identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30, at most 90% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30 or at most 95% amino acid identity with amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. [0482] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1064 1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1064-1076 or amino acids 1105 1114 of SEQ ID NO: 30 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a 3-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. [0483] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1064-1076 or amino acids 1105 214 of 316 WO 2006/101809 PCT/US2006/008956 1114 of SEQ ID NO: 30. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1064 1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1064-1076 or amino acids 1105-1114 of SEQ ID NO: 30. [0484] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1017-1166 of SEQ ID NO: 31. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype F NTNH, a P-fold motif of a p-trefoil domain of a Clostridial botulinum serotype F NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. [0485] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1017-1166 of SEQ ID NO: 31. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modified a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype F NTNH, a modified 0-fold 215 of 316 WO 2006/101809 PCT/US2006/008956 motif of a p-trefoil domain of a Clostridial botulinum serotype F NTNH or a modified V-fold motif of a p trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. [0486] In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at least 75% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at least 80% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at least 85% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at least 90% amino acid Identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31 or at least 95% amino acid identity with amino acids 1017-1064, amino acids 1078 1106, or amino acids 1117-1166 of SEQ ID NO: 31. In yet other aspects of this embodiment, a Clostidial botulinum serotype F NTNH comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1017-1064, amino acids 1078 1106, or amino acids 1117-1166 of SEQ ID NO: 31, at most 75% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at most 80% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at most 85% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31, at most 90% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31 or at most 95% amino acid identity with amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. [0487] In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. in other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In yet other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide 216 of 316 WO 2006/101809 PCT/US2006/008956 having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In still other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1017 1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. [0488] In other aspects of this embodiment, a Clostridial botullnum serotype F NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1017-1064, amino acids 1078 1106, or amino acids 1117-1166 of SEQ ID NO: 31. In yet other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117 1166 of SEQ ID NO: 31. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In still other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1017-1064, amino acids 1078-1106, or amino acids 1117-1166 of SEQ ID NO: 31. In other aspects of this embodiment, a Clostridial botulinum serotype F NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1017-1064, amino acids 1078 1106, or amino acids 1117-1166 of SEQ ID NO: 31. [0489] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises a 04/05 hairpin tum of a 0-trefoil domain of a Clostridial botulinum serotype F NTNH or a 08/09 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In 217 of 316 WO 2006/101809 PCT/US2006/008956 another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype F NTNH comprises amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. [0490] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modified P4/P5 hairpin turn of a P-trefoll domain of a Clostridial botulinum serotype F NTNH or a modified P8/39 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype F NTNH of SEQ ID NO: 31. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a modification of amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. [0491] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at least 75% amino acid Identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at least 80% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at least 85% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at least 90% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31 or at least 95% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at most 75% amino acid Identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at most 80% amino acid Identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at most 85% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31, at most 90% amino acid identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31 or at most 95% amino acid Identity with amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. [0492] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1065 1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1065-1077 or amino acids 1107 1116 of SEQ ID NO: 31 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31 can be replaced with phenylalanine. In yet other aspects of this 218 of 316 WO 2006/101809 PCTIUS2006/008956 embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. [0493] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1065-1077 or amino acids 1107 1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1065 1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype F NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1065-1077 or amino acids 1107-1116 of SEQ ID NO: 31. 219 of 316 WO 2006/101809 PCT/US2006/008956 [0494] In another embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another embodiment, a 13-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises amino acids 1050-1199 of SEQ ID NO: 32. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises a a-fold motif of a 0-trefoil domain of a Clostridial botulinum serotype G NTNH, a s-fold motif of a P-trefoil domain of a Clostridial botulinum serotype G NTNH or a y-fold motif of a P-trefoil domain of a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. [0495] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises amino acids 1050-1199 of SEQ ID NO: 32. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a modified a-fold motif of a P-trefoil domain of a Clostridial botulinum serotype G NTNH, a modified 0-fold motif of a P-trefoil domain of a Clostridial botulinum serotype G NTNH or a modified y-fold motif of a p trefoil domain of a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridlal botulinum serotype G NTNH comprises amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. [0496] In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at least 75% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at least 80% amino acid Identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at least 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at least 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32 or at least 95% amino acid identity with amino acids 1050-1097, amino acids 1111 1139, or amino acids 1150-1199 of SEQ ID NO: 32. In yet other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 1050-1097, amino acids 1111 1139, or amino acids 1150-1199 of SEQ ID NO: 32, at most 75% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at most 80% amino acid Identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID 220 of 316 WO 2006/101809 PCT/US2006/008956 NO: 32, at most 85% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32, at most 90% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32 or at most 95% amino acid identity with amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. [0497] In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In yet other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111 1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In still other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a 5-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. [0498] In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. in yet other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 221 of 316 WO 2006/101809 PCT/US2006/008956 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In still other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111-1139, or amino acids 1150-1199 of SEQ ID NO: 32. In other aspects of this embodiment, a Clostridial botulinum serotype G NTNH comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 1050-1097, amino acids 1111 1139, or amino acids 1150-1199 of SEQ ID NO: 32. [0499] In another embodiment, a 8-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises a 04/5 hairpin turn of a u-trefoil domain of a Clostridial botulinum serotype G NTNH or a @8/09 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another aspect of this embodiment, a B-trefoil domain derived from a Clostridial botulinum serotype G NTNH comprises amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. [0500] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a modified 04/05 hairpin turn of a p-trefoil domain of a Clostridial botulinum serotype G NTNH or a modified P8/P9 hairpin turn of a P-trefoil domain of a Clostridial botulinum serotype G NTNH of SEQ ID NO: 32. In another aspect of this embodiment, a B trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a modification of amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. [0501] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at least 75% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at least 80/6 amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at least 85% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at least 90% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32 or at least 95% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at most 75% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at 222 of 316 WO 2006/101809 PCT/US2006/008956 most 80% amino acid Identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at most 85% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32, at most 90% amino acid Identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32 or at most 95% amino acid identity with amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. [0502] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 1098 1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a non contiguous amino acid substitution of any amino acid from amino acids 1098-1110 or amino acids 1140 1149 of SEQ ID NO: 32 can be replaced with glycine. In other aspects of this embodiment, a non contiguous amino acid substitution of any hydrophobic amino acid from amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a B-trefol domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. [0503] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140 1149 of SEQ ID NO: 32. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32 223 of 316 WO 2006/101809 PCT/US2006/008956 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 1098 1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In still other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a Clostridial botulinum serotype G NTNH comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 1098-1110 or amino acids 1140-1149 of SEQ ID NO: 32. [05041 Another example of an enhanced targeting domain that increases binding activity for an endogenous Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell, includes, without limitation, ligands that bind the same receptor systems as naturally-occurring Clostridial toxins. Recent studies are revealing components of the endogenous receptor systems used by a Clostridial toxin during the intoxication process. As a non-limiting example, fibroblast growth factor 3 receptor (FGFR3) serves as a BoNT/A receptor, see, e.g., Ester Fernandez-Salas et al., Botulinum Toxin Screening Assays, PCT Patent Application No. 2005/006421 (Sep., 9, 2005). As another non-limiting example, synaptotagmin I serves as a BoNT/B receptor and as a BoNT/G receptor, see, e.g., Min Dong et al., Synaptotagmins I and I mediate entry of botulinum neurotoxin B into cells, 162(7) J. Cell Blol. 1293-1303 (2003); and Andreas Rummel et al., Synaptotagmins I and II act as nerve cell receptors for botulinum neurotoxin G, 279(29) J. Blol. Chem. 30865-30870 (2004). As yet another non-limiting example, synaptotagmin il serves as a BoNT/B receptor and as a BoNT/G receptor, see, e.g., Min Dong et al., supra, (2003); and Andreas Rummel et al., supra, (2004). The selection of a ligand domain as an enhanced binding region will depend on the Clostridial toxin being modified. As non-Ilmiting examples, ligands that selectively bind to a FGFR3 could be used as an enhanced targeting domain for a modified BoNT/A, whereas ligands that selectively bind a Synaptotagmin I or Synaptotagmin Il could be used as an enhanced targeting domain for a modified BoNT/B or a modified BoNT/G. [0505] Fibroblast growth factors (FGF) participate In many developmental, differentiation and growth and repair processes of cells through complex combinatorial signaling pathways. Presently, at least 23 ligands (FGF1-23) are known to signal through a family of five transmembrane tyrosine kinase FGF receptors (FGFR1-5). Affinity of FGFRs for their ligands is highly diverse with different affinities for each family member of growth factors, see, e.g., C. J. Powers et al., Fibroblast growth factors, their receptors and 224 of 316 WO 2006/101809 PCT/US2006/008956 signaling, 7(3) Endocr. Relat. Cancer. 165-197 (2000). This diversity is achieved in part by the generation of alternatively spliced variants encoding distinct receptor isoforms, see, e.g., Bernhard Reuss & Oliver von Bohlen und Halbach, Fibroblast growth factors and their receptors in the central nervous system, 313(2) Cell Tissue Res. 139-157 (2003). The protein region that appears to have the highest influence on ligand binding selectivity is a portion of the igIll domain, for which isoforms encoded by three different splice variants have been identified. These three Isoforms, designated Igilla, IgIlib and IgIlIc, have relative binding affinities for different FGFR family members. Alternative splicing in the FGFR ligand binding domain, designated a and b, generates additional receptor isoforms with novel ligand affinities. Isoforms for igilla, IgIllb and Igilic have been identified for both FGFR1 and FGFR2. Thus far, the Igllla isoform of FGFR3 and the IgIlla and Igilib isoforms of FGFR4 and FGFRS have not been reported. (0506] Currently, several FGFs have been shown to selectively bind FGFR3, such as, e.g., FGF-1, FGF 2, FGF-4, FGF-8, FGF-9, FGF-17 and FGF-18, see, e.g., Hecht et al., 1995; Omitz et al., 1996; and Xu et al., 2000. Additional studies have revealed that FGF-1 and FGF9 preferentially bind FGFR31i1b, whereas FGF-1 FGF-2, FGF-4, FGF-8, and FGF9 preferentially bind FGFR31i1c. Studies have shown that each of these ligands is present in various vertebrate species with a high degree of sequence identity which suggests functional equivalence or similarity. As a non-limiting example, FGF-8 Is found in fish, birds and mammals and each of these FGF-8 ligands have over 80% amino acid sequence identity. As another non-limiting example, FGF-18 is found in fish, birds and mammals and each of these FGF-18 ligands have over 70% amino acid sequence identity. Crystallographic studies have revealed that all FGFs are structurally organized into a P-trefoil domain. The amino acid sequences comprising the B-trefoil domains found in various FGF ligands that bind FGFR3 are shown in Table 7. Table 7. A.trefoiDomains of FGFs Amino Acid Sequence Region of Carbohydrate Binding Moieties Ligand SEQ ID.NO - -- a-fold #40 B-fold y-8/s9 a- s-hairpin turn -hairpin turn y-fold FGF-1 33 26-64 65-67 68-105 106-108 109-155 FGF-2 34 29-67 68-70 71-111 112-114 115-155 FGF-4 35 83-121 122-124 125-162 163-165 166-206 FGF-8 36 43-80 81-83 84-123 124-126 127-172 FGF-9 37 63-100 101-103 104-144 145-147 148-196 FGF-17 38 55-91 92-94 95-134 135-137 138-183 FGF-18 39 54-91 92-94 95-134 135-137 138-183 [0507] As used herein, the term "Fibroblast Growth Factor" is synonymous with "FGF" and means a polypeptide with selective binding activity, such as, e.g., a binding affinity or a binding specificity, for a receptor system, including endogenous Clostridial toxin receptor systems such as, e.g., a receptor system comprising FGFR3. It is envisioned that both naturally occurring FGFs as well as FGFs with enhanced 225 of 316 WO 2006/101809 PCTIUS2006/008956 Dining activity can be used to practice aspects of the present invention. As used herein, the term "FGF with enhanced binding activity" means a FGF with enhanced binding activity for an endogenous Clostridial toxin receptor system, such as, e.g., a binding affinity or a binding specificity, to a statistically significantly degree relative to an unmodified naturally occurring Clostridial toxin binding domain from a Clostridial toxin. By definition, a FGF with enhanced binding activity has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 7) and can be described In percent identity to the corresponding region of that reference sequence. [0508] Any of a variety of sequence alignment methods can be used to determine percent identity of a modified FGF relative to a naturally-occurring FGF, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled In the art and from the teaching herein. [0509] Approaches well known to one skilled in the art on how to modify a FGF in order to increase its binding activity for an endogenous Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell. As described above, one approach Involves Identifying amino acids using computational protein design algorithims; changing specifically-Identified amino acids using, without limitation, site-directed mutagenesis, oligonucleotide-directed mutagenesis and site-specific mutagenesis; and testing the binding activity of modified Clostridial toxins comprising a modified FGF with enhanced binding activity using, e.g., heterogeneous assays, homogeneous assays and non-separating homogeneous assays. It is further envisioned that the binding activity of a modified Clostridial toxin with enhanced binding activity disclosed in the present specification can be determined by affinity chromatography using immobilized receptors and interfacial optical assays. In another approach described above, a binding activity of a modified FGF for a naturally-occurring Clostridial toxin receptor system present on a naturally-occurring Clostridial toxin target cell can be achieved using directed evolution methods. [0510] A FGF includes, without limitation, naturally occurring FGF variants, such as, e.g., FGF isoforms and FGF subtypes; non-naturally occurring FGF variants, such as, e.g., conservative FGF variants, non conservative FGF variants, FGF chimerics, active FGF fragments thereof, or any combination thereof. [0511] As used herein, the term "FGF variant," whether naturally-occurring or non-naturally-occurring, means a FGF that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Tables 7) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all FGF variants disclosed in the present specification are capable of executing the cell binding step of the intoxication process. [0512] It is recognized by those of skill in the art that within each Clostridial bacterium there can be naturally occurring FGF variants that differ somewhat in their amino acid sequence, and also in the 226 of 316 WO 2006/101809 PCT/US2006/008956 nucleic acids encoding these proteins. For example, there are presently at least four FGF-8 variants, FGF-8A, FGF-8A, FGF-8B, FGF-8E and FGF-8F, with specific FGF-8 variants showing various degrees of amino acid divergence when compared to another FGF-8 variant. As another example, there are presently at least two FGF-2 variants, FGF-2-1 and FGF-2-1, with the FGF-2-1 variant showing an amino acid divergence when compared to the FGF-2-2 variant. As used herein, the term "naturally occurring FGF variant" means any FGF produced by a naturally-occurring process, including, without limitation, FGF Isoforms produced from alternatively-spliced transcripts, FGF isoforms produced by spontaneous mutation and FGF subtypes. A naturally occurring FGF variant can function in substantially the same manner as the reference FGF on which the naturally occurring FGF variant is based, and can be substituted for the reference FGF in any aspect of the present invention. A naturally occurring FGF variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference FGF on which the naturally occurring FGF variant is based. A naturally occurring FGF variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference FGF on which the naturally occurring FGF variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference FGF on which the naturally occurring FGF variant is based. [0513] A non-limiting examples of a naturally occurring FGF variant is a FGF isoform such as, e.g., a FGF-1 isoform, a FGF-2 isoform, a FGF-4 isoform, a FGF-8 isoform, a FGF-9 isoform, a FGF-17 isoform and a FGF-18 Isoform. A FGF Isoform can function in substantially the same manner as the reference FGF on which the FGF isoform is based, and can be substituted for the reference FGF In any aspect of the present invention. [0514] Another non-limiting examples of a naturally occurring FGF variant Is a FGF subtype such as, e.g., a FGF-1 subtype, a FGF-2 subtype, a FGF-4 subtype, a FGF-8 subtype, a FGF-9 subtype, a FGF-17 subtype and a FGF-18 subtype. A FGF subtype can function in substantially the same manner as the reference FGF on which the FGF subtype is based, and can be substituted for the reference FGF In any aspect of the present invention. [0515] As used herein, the term "non-naturally occurring FGF variant" means any FGF produced with the aid of human manipulation, including, without limitation, FGFs produced by genetic engineering using random mutagenesis or rational design and FGFs produced by chemical synthesis. Non-limiting examples of non-naturally occurring FGF variants Include, e.g., conservative FGF variants, non conservative FGF variants, FGF chimeric variants and active FGF fragments. 227 of 316 WO 2006/101809 PCT/US2006/008956 [0516] As used herein, the term "conservative FGF variant" means a FGF that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference FGF sequence (see Table 7). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative FGF variant can function in substantially the same manner as the reference FGF on which the conservative FGF variant Is based, and can be substituted for the reference FGF in any aspect of the present invention. A conservative FGF variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids or 50 or more amino acids from the reference FGF on which the conservative FGF variant is based. A conservative FGF variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference FGF on which the conservative FGF variant is based, that possess at least 50% amino acid Identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference FGF on which the conservative FGF variant is based. Non-limiting examples of a conservative FGF variant include, e.g., a conservative FGF-1 variant, a conservative FGF-2 variant, a conservative FGF-4 variant, a conservative FGF-8 variant, a conservative FGF-9 variant, a conservative FGF-1 7 variant and a conservative FGF-1 8 variant. [0517] As used herein, the term "non-conservative FGF variant" means a FGF in which 1) at least one amino acid is deleted from the reference FGF on which the non-conservative FGF variant is based; 2) at least one amino acid added to the reference FGF on which the non-conservative FGF is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference FGF sequence (see Table 7). A non-conservative FGF variant can function in substantially the same manner as the reference FGF on which the non-conservative FGF variant Is based, and can be substituted for the reference FGF In any aspect of the present invention. A non-conservative FGF variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference FGF on which the non-conservative FGF variant Is based. A non-conservative FGF variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference FGF on which the non-conservative FGF variant is based. A non-conservative FGF variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids or 50 or more amino acids from the reference FGF on which the non-conservative FGF variant is based. A non-conservative FGF variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference FGF on which the non 228 of 316 WO 2006/101809 PCT/US2006/008956 conservative FGF variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid Identity to the reference FGF on which the non-conservative FGF variant is based. Non-limiting examples of a non-conservative FGF variant include, e.g., a non-conservative FGF-1 variant, a non-conservative FGF-2 variant, a non conservative FGF-4 variant, a non-conservative FGF-8 variant, a non-conservative FGF-9 variant, a non conservative FGF-1 7 variant and a non-conservative FGF-1 8 variant. [0518] As used herein, the term "FGF chimeric" means a polypeptide comprising at least a portion of a FGF and at least a portion of at least one other polypeptide to form an enhanced targeting domain with at least one property different from the reference FGF (see Tables 7), with the proviso that this FGF chimeric can specifically bind to an endogenous Clostridial toxin receptor system present in a Clostridial toxin target cell, and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. [0519] Thus, in an embodiment, a modified Clostridlal toxin disclosed In the present specification comprises an enhanced targeting domain comprising a B-trefoil domain derived from a FGF. In an aspect of this embodiment, a B-trefoil domain derived from a FGF comprises, e.g., a B-trefoil domain derived from a FGF-1, a B-trefoil domain derived from a FGF-2, a B-trefoil domain derived from FGF-4, a B-trefoil domain derived from a FGF-8, a B-trefoil domain derived from a FGF-9, a B-trefoil domain derived from a FGF-17 or a B-trefoil domain derived from a FGF-18. In another aspect of this embodiment, a B-trefoil domain derived from a FGF comprises a a-fold motif of a 1-trefoil domain of a FGF, a -fold motif of a 0 trefoil domain of a FGF or a y-fold motif of a 0-trefoil domain of a FGF. [0520] In an embodiment, a modified Clostridial toxin disclosed in the present specification comprises an enhanced targeting domain comprising a B-trefoil domain with enhanced binding activity derived from a FGF. In an aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF comprises, e.g., a B-trefoil domain with enhanced binding activity derived from a FGF-1, a B-trefoil domain with enhanced binding activity derived from a FGF-2, a B-trefoil domain with enhanced binding activity derived from a FGF-4, a B-trefoil domain with enhanced binding activity derived from a FGF-8, a B-trefoil domain with enhanced binding activity derived from a FGF-9, a B-trefoil domain with enhanced binding activity derived from a FGF-17 or a B-trefoil domain with enhanced binding activity derived from a FGF-1 8. in another aspect of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF comprises a modified a-fold motif of a p-trefoil domain of a FGF, a modified 0-foid motif of a 1-trefoil domain of a FGF or a modified y-fold motif of a p-trefoil domain of a FGF. [0521] In another embodiment, a B-trefoil domain derived from a FGF-1 comprises a B-trefoil domain derived from a FGF-1 of SEQ ID NO: 33. In another embodiment, a 13-trefoli domain derived from a FGF 1 comprises amino acids 26-155 of SEQ ID NO: 33. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-1 comprises a a-fold motif of a 1-trefoil domain of a FGF-1, a 3-fold motif of a 229 of 316 WO 2006/101809 PCT/US2006/008956 0-trefoil domain of a FGF-1 or a y-fold motif of a 0-trefoil domain of a FGF-1 of SEQ ID NO: 33. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-1 comprises amino acids 26 64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. [0522] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a 8-trefoil domain with enhanced binding activity derived from a FGF-1 of SEQ ID NO: 33. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises amino acids 26-155 of SEQ ID NO: 33. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a modified a-fold motif of a S-trefoil domain of a FGF-1, a modified -fold motif of a P-trefoil domain of a FGF-1 or a modified y-fold motif of a 0-trefoil domain of a FGF-1 of SEQ ID NO: 33. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. [0523] In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at least 75% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at least 80% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at least 85% amino acid Identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at least 90% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33 or at least 95% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In yet other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109 155 of SEQ ID NO: 33, at most 75% amino acid Identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at most 80% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at most 85% amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33, at most 90/6 amino acid identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33 or at most 95% amino acid Identity with amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. [0524] In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 26-64, amino acids 68 105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions 230 of 316 WO 2006/101809 PCTIUS2006/008956 relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In yet other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In still other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. [0525] In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In yet other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In still other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. In other aspects of this embodiment, a FGF-1 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 26-64, amino acids 68-105, or amino acids 109-155 of SEQ ID NO: 33. 231 of 316 WO 2006/101809 PCT/US2006/008956 (0526] in another embodiment, a 13-trefoil domain derived from a FGF-1 comprises a [4/05 hairpin turn of a p-trefoil domain of a FGF-1 or a 08/09 hairpin turn of a [-trefoil domain of a FGF-1 of SEQ ID NO: 33. In another aspect of this embodiment, a 13-trefoil domain derived from a FGF-1 comprises amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. [0527] in another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a modified 04/05 hairpin turn of a [-trefoil domain of a FGF-1 or a modified 08/09 hairpin turn of a P-trefoil domain of a FGF-1 of SEQ ID NO: 33. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a modification of amino acids 65 67 or amino acids 106-108 of SEQ ID NO: 33. [0528] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 65 67 or amino acids 106-108 of SEQ ID NO: 33, at least 75% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at least 80% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at least 85% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at least 90% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 or at least 95% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at most 75% amino acid Identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at most 80% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at most 85% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33, at most 90% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 or at most 95% amino acid identity with amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. [0529] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions 232 of 316 WO 2006/101809 PCT/US2006/008956 relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, -e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. [0530] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 65-67 or amino acids 106-108 of SEQ ID NO: 33. [0531] In another embodiment, a B-trefoil domain derived from a FGF-2 comprises a B-trefoil domain derived from a FGF-2 of SEQ ID NO: 34. In another embodiment, a B-trefoil domain derived from a FGF 2 comprises amino acids 29-155 of SEQ ID NO: 34. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-2 comprises a a-fold motif of a p-trefoil domain of a FGF-2, a p-fold motif of a P-trefoil domain of a FGF-2 or a y-fold motif of a p-trefoil domain of a FGF-2 of SEQ ID NO: 34. In 233 of 316 WO 2006/101809 PCT/US2006/008956 another aspect of this embodiment, a B-trefoil domain derived from a FGF-2 comprises amino acids 29 67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. [0532] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a B-trefoil domain with enhanced binding activity derived from a FGF-2 of SEQ ID NO: 34. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises amino acids 29-155 of SEQ ID NO: 34. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a modified a-fold motif of a P-trefoil domain of a FGF-2, a modified p-fold motif of a P-trefoil domain of a FGF-2 or a modified y-fold motif of a P-trefoil domain of a FGF-2 of SEQ ID NO: 34. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. [0533] In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at least 75% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at least 80% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at least 85% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at least 90% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34 or at least 95% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In yet other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115 155 of SEQ ID NO: 34, at most 75% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at most 80% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at most 85% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34, at most 900/ amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34 or at most 95% amino acid identity with amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. [0534] In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 29-67, amino acids 71 111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In yet 234 of 316 WO 2006/101809 PCT/US2006/008956 other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In still other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. [0535] in other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In yet other aspects of this embodiment, a FGF-2 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In still other aspects of this embodiment, a FGF-2 comprising a 13-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. In other aspects of this embodiment, a FGF-2 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 29-67, amino acids 71-111, or amino acids 115-155 of SEQ ID NO: 34. [0536] In another embodiment, a B-trefoil domain derived from a FGF-2 comprises a p4/p5 hairpin turn of a P-trefoil domain of a FGF-2 or a 08/09 hairpin turn of a p-trefoil domain of a FGF-2 of SEQ ID NO: 235 of 316 WO 2006/101809 PCT/US2006/008956 34. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-2 comprises amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. [0537] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a modified 04/05 hairpin turn of a P-trefoil domain of a FGF-2 or a modified 08/P9 hairpin tum of a p-trefoil domain of a FGF-2 of SEQ ID NO: 34. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a modification of amino acids 68 70 or amino acids 112-114 of SEQ ID NO: 34. [0538] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 68 70 or amino acids 112-114 of SEQ ID NO: 34, at least 75% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at least 80% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at least 85% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at least 90% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 or at least 95% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at most 75% amino acid Identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at most 80% amino acid Identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at most 85% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34, at most 90% amino acid identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 or at most 95% amino acid Identity with amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. [0539] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a -trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a 236 of 316 WO 2006/101809 PCT/US2006/008956 polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. [0540] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-2 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 68-70 or amino acids 112-114 of SEQ ID NO: 34. [0541] In another embodiment, a B-trefoil domain derived from a FGF-4 comprises a B-trefoil domain derived from a FGF-4 of SEQ ID NO: 35. In another embodiment, a B-trefoil domain derived from a FGF 4 comprises amino acids 83-206 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-4 comprises a a-fold motif of a p-trefoll domain of a FGF-4, a p-fold motif of a p-trefoil domain of a FGF-4 or a y-fold motif of a p-trefoil domain of a FGF-4 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-4 comprises amino acids 83 121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. 237 of 316 WO 2006/101809 PCT/US2006/008956 [0542] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a 8-trefoil domain with enhanced binding activity derived from a FGF-4 of SEQ ID NO: 35. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises amino acids 83-206 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a modified a-fold motif of a P-trefoil domain of a FGF-4, a modified 0-fold motif of a ft-trefoil domain of a FGF-4 or a modified y-fold motif of a P-trefoil domain of a FGF-4 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. [0543] In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at least 75% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at least 80% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at least 85% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at least 90% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEO ID NO: 35 or at least 95% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In yet other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at most 75% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at most 80% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at most 65% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35, at most 90% amino acid identity with amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35 or at most 95% amino acid identity with amino acids 83-121, amino acids 125 162, or amino acids 166-206 of SEQ ID NO: 35. [0544] in other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 83-121, amino acids 125 162, or amino acids 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In yet other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 83-121, amino acids 125-162, or amino acids 238 of 316 WO 2006/101809 PCT/US2006/008956 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In still other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non contiguous amino acid additions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. [0545] In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a 13 trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In yet other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In still other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. In other aspects of this embodiment, a FGF-4 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 83-121, amino acids 125-162, or amino acids 166-206 of SEQ ID NO: 35. [0546] In another embodiment, a 1-trefoil domain derived from a FGF-4 comprises a 04/P5 hairpin turn of a -trefoil domain of a FGF-4 or a p8/09 hairpin turn of a p-trefoil domain of a FGF-4 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-4 comprises amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. 239 of 316 WO 2006/101809 PCT/US2006/008956 [0547] In another embodiment, a B-trefoli domain with enhanced binding activity derived from a FGF-4 comprises a modified p4/P5 hairpin turn of a P-trefoil domain of a FGF-4 or a modified 08/P9 hairpin turn of a P-trefoil domain of a FGF-4 of SEQ ID NO: 35. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a modification of amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. [0548] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at least 75% amino acid Identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at least 80% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at least 85% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at least 90% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35 or at least 95% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at most 75% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at most 80% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35, at most 85% amino acid identity with amino acids 122-124 or amino acids 163-165 of SEQ iD NO: 35, at most 90% amino acid Identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35 or at most 95% amino acid Identity with amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. [0549] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 122 124 or amino acids 163-165 of SEQ ID NO: 35 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a 240 of 316 WO 2006/101809 PCTIUS2006/008956 polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. [0550] In other aspects of this embodiment, a B-trefoli domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-4 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 122-124 or amino acids 163-165 of SEQ ID NO: 35. [0551] In another embodiment, a B-trefoli domain derived from a FGF-8 comprises a B-trefoil domain derived from a FGF-8 of SEQ ID NO: 36. In another embodiment, a B-trefoil domain derived from a FGF 8 comprises amino acids 43-172 of SEQ ID NO: 36. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-8 comprises a a-fold motif of a 0-trefoil domain of a FGF-8, a p-fold motif of a 0-trefoil domain of a FGF-8 or a y-fold motif of a P-trefoil domain of a FGF-8 of SEQ ID NO: 36. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-8 comprises amino acids 43 80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. [0552] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a B-trefoil domain with enhanced binding activity derived from a FGF-8 of SEQ ID NO: 36. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises 241 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 43-172 of SEQ ID NO: 36. In another aspect of this embodiment, a a-trefoil domain with enhanced binding activity derived from a-FGF-8 comprises a modified a-fold motif of a P-trefoil domain of a FGF-8, a modified P-fold motif of a 0-trefoil domain of a FGF-8 or a modified y-fold motif of a P-trefoil domain of a FGF-B of SEQ ID NO: 36. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. [0553] In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at least 75% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at least 80% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at least 85% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at least 90% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36 or at least 95% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In yet other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid Identity with amino acids 43-80, amino acids 84-123, or amino acids 127 172 of SEQ ID NO: 36, at most 75% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at most 80% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at most 85% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36, at most 90% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36 or at most 95% amino acid identity with amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. [0554] In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 43-80, amino acids 84 123, or amino acids 127-172 of SEQ ID NO: 36. In other aspects of this embodiment, a FGF-8 comprising a 6-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. in yet other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 43-80, amino 242 of 316 WO 2006/101809 PCTIUS2006/008956 acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In still other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. (0555] In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In other aspects of this embodiment, a FGF-8 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In yet other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. In still other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. in other aspects of this embodiment, a FGF-8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 43-80, amino acids 84-123, or amino acids 127-172 of SEQ ID NO: 36. [0556] In another embodiment, a B-trefoil domain derived from a FGF-8 comprises a 04/p5 hairpin turn of a P-trefoil domain of a FGF-8 or a 08/09 hairpin tum of a 0-trefoil domain of a FGF-8 of SEQ ID NO: 36. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-8 comprises amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. [0557] In another embodiment, a 8-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a modified 04/05 hairpin tum of a p-trefoil domain of a FGF-8 or a modified 08/139 hairpin tum of a -trefoil domain of a FGF-8 of SEQ ID NO: 36. In another aspect of this embodiment, a B-trefoil 243 of 316 WO 2006/101809 PCTIUS2006/008956 domain with enhanced binding activity derived from a FGF-8 comprises a modification of amino acids 81 83 or amino acids 124-126 of SEQ ID NO: 36. [0558] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 81 83 or amino acids 124-126 of SEQ ID NO: 36, at least 75% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at least 80% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at least 85% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at least 90% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 or at least 95% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at most 75% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at most 80% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at most 85% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36, at most 90% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 or at most 95% amino acid identity with amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. [0559] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoll domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, 244 of 316 WO 2006/101809 PCT/US2006/008956 three or four non-contiguous amino acid additions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. [0560] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-8 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 81-83 or amino acids 124-126 of SEQ ID NO: 36. [0561] In another embodiment, a B-trefoil domain derived from a FGF-9 comprises a B-trefoil domain derived from a FGF-9 of SEQ ID NO: 37. In another embodiment, a B-trefoil domain derived from a FGF 9 comprises amino acids 63-196 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-9 comprises a a-fold motif of a P-trefoil domain of a FGF-9, a 0-fold motif of a 0-trefoil domain of a FGF-9 or a y-fold motif of a 0-trefoil domain of a FGF-9 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-9 comprises amino acids 63 100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. [0562] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a 3-trefoil domain with enhanced binding activity derived from a FGF-9 of SEQ ID NO: 37. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises amino acids 63-196 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a modified a-fold motif of a 0-trefoil domain of a FGF-9, a modified 0-fold motif of a P-trefoil domain of a FGF-9 or a modified y-fold motif of a p-trefoil 245 of 316 WO 2006/101809 PCT/US2006/008956 domain of a FGF-9 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. [0563] In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at least 75% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at least 80% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at least 85% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at least 90% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37 or at least 95% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In yet other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at most 75% amino acid Identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at most 80% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at most 85% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37, at most 90% amino acid identity with amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37 or at most 95% amino acid Identity with amino acids 63-100, amino acids 104 144, or amino acids 148-196 of SEQ ID NO: 37. [0564] In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 63-100, amino acids 104 144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In yet other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In still other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non 246 of 316 WO 2006/101809 PCT[US2006/008956 contiguous amino acid additions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. [05651 In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In yet other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In still other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. In other aspects of this embodiment, a FGF-9 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 63-100, amino acids 104-144, or amino acids 148-196 of SEQ ID NO: 37. [0566] In another embodiment, a B-trefoil domain derived from a FGF-9 comprises a 4/p5 hairpin turn of a P-trefoil domain of a FGF-9 or a 08/09 hairpin turn of a p-trefoll domain of a FGF-9 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-9 comprises amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. [0567] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a modified p4/p5 hairpin turn of a p-trefoil domain of a FGF-9 or a modified p8/P9 hairpin turn of a P-trefoil domain of a FGF-9 of SEQ ID NO: 37. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a modification of amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. 247 of 316 WO 2006/101809 PCT/US2006/008956 [0568] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at least 75% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at least 80% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at least 85% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at least 90% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37 or at least 95% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at most 75% amino acid Identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at most 80% amino acid Identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at most 85% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37, at most 90% amino acid identity with amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37 or at most 95% amino acid identity with amino acids 101 -103 or amino acids 145-147 of SEQ ID NO: 37. [0569] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 101 -103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a (-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 101 103 or amino acids 145-147 of SEQ ID NO: 37 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. 248 of 316 WO 2006/101809 PCTIUS2006/008956 [0570] In other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a 1-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 101 -103 or amino acids 145-147 of SEQ ID NO: 37. In still other aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-9 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 101-103 or amino acids 145-147 of SEQ ID NO: 37. (05711 In another embodiment, a B-trefoil domain derived from a FGF-17 comprises a B-trefoil domain derived from a FGF-17 of SEQ ID NO: 38. In another embodiment, a 13-trefoil domain derived from a FGF-17 comprises amino acids 55-183 of SEQ ID NO: 38. In another aspect of this embodiment, a B trefoil domain derived from a FGF-1 7 comprises a a-fold motif of a 0-trefoil domain of a FGF-1 7, a p-fold motif of a p-trefoil domain of a FGF-17 or a y-fold motif of a p-trefoi domain of a FGF-17 of SEQ ID NO: 38. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-17 comprises amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. [0572] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a B-trefoil domain with enhanced binding activity derived from a FGF-17 of SEQ ID NO: 38. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises amino acids 55-183 of SEQ ID NO: 38. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a modified a-fold motif of a P-trefoi domain of a FGF-17, a modified 0-fold motif of a S-trefoil domain of a FGF-17 or a modified y-fold motif of a 0 trefoil domain of a FGF-17 of SEQ ID NO: 38. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. 249 of 316 WO 2006/101809 PCTIUS2006/008956 [0573] in other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at least 75% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at least 80% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at least 85% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at least 90% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38 or at least 95% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In yet other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138 183 of SEQ ID NO: 38, at most 75% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at most 80% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at most 85% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38, at most 90% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38 or at most 95% amino acid identity with amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. [0574] in other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 55-91, amino acids 95 134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In yet other aspects of this embodiment, a FGF-1 7 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. in still other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 250 of 316 WO 2006/101809 PCT/US2006/008956 or 20 non-contiguous amino acid additions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. [0575] In other aspects of this embodiment, a FGF-17 comprising a (3-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In yet other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In still other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. In other aspects of this embodiment, a FGF-17 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 55-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 38. [0576] In another embodiment, a B-trefoil domain derived from a FGF-17 comprises a 04/05 hairpin turn of a P-trefoil domain of a FGF-17 or a P8/09 hairpin turn of a P-trefoil domain of a FGF-17 of SEQ ID NO: 38. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-17 comprises amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. [0577] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a modified 04/P5 hairpin turn of a -trefoil domain of a FGF-17 or a modified P8/P9 hairpin turn of a 1-trefoil domain of a FGF-17 of SEQ ID NO: 38. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a modification of amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. [0578] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at least 75% amino acid identity with amino acids 92-94 251 of 316 WO 2006/101809 PCT/US2006/008956 or amino acids 135-137 of SEQ ID NO: 38, at least 80% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at least 85% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, -at least 90% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 or at least 95% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at most 75% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at most 80% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at most 85% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38, at most 90% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 or at most 95% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. [0579] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF 17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 7 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. [0580] In other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other 252 of 316 WO 2006/101809 PCT/US2006/008956 aspects of this embodiment, a 8-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, contiguous amino acid substitutions of amino acids from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-17 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 38. [0581] In another embodiment, a a-trefoil domain derived from a FGF-18 comprises a B-trefoil domain derived from a FGF-18 of SEQ ID NO: 39. In another embodiment, a B-trefoil domain derived from a FGF-18 comprises amino acids 54-183 of SEQ ID NO: 39. In another aspect of this embodiment, a B trefoil domain derived from a FGF-1 8 comprises a a-fold motif of a p-trefoil domain of a FGF-1 8, a P-fold motif of a p-trefoil domain of a FGF-18 or a y-fold motif of a p-trefoil domain of a FGF-18 of SEQ ID NO: 39. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-18 comprises amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. [0582] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a B-trefoil domain with enhanced binding activity derived from a FGF-18 of SEQ ID NO: 39. In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises amino acids 54-183 of SEQ ID NO: 39. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a modified a-fold motif of a P-trefoil domain of a FGF-18, a modified P-fold motif of a P-trefoil domain of a FGF-18 or a modified y-fold motif of a 0 trefoil domain of a FGF-18 of SEQ ID NO: 39. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. [0583] In other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 253 of 316 WO 2006/101809 PCTIUS2006/008956 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at least 75% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at least 80% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at least 85% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at least 90% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39 or at least 95% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In yet other aspects of this embodiment, a FGF-18 comprising a 5-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138 183 of SEQ ID NO: 39, at most 75% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at most 80% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at most 85% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39, at most 90% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39 or at most 95% amino acid identity with amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. [0584] In other aspects of this embodiment, a FGF-18 comprising a -trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 54-91, amino acids 95 134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-18 comprising a 5-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid substitutions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In yet other aspects of this embodiment, a FGF-18 comprising a 8-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid deletions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In still other aspects of this embodiment, a FGF-18 comprising a 5-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 non-contiguous amino acid additions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. 254 of 316 WO 2006/101809 PCTIUS2006/008956 .uotaj in oiner aspects oT nis emuuuiment, a i-ui--i comprising a i)-trdiuu uumain witn ennanceo binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-18 comprising a B trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid substitutions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In yet other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-1 8 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid deletions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In still other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. In other aspects of this embodiment, a FGF-18 comprising a B-trefoil domain with enhanced binding activity comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10 or 20 contiguous amino acid additions relative to amino acids 54-91, amino acids 95-134, or amino acids 138-183 of SEQ ID NO: 39. [0586] in another embodiment, a B-trefoil domain derived from a FGF-18 comprises a 04/05 hairpin turn of a -trefoil domain of a FGF-18 or a 08/09 hairpin turn of a 0-trefoil domain of a FGF-18 of SEQ ID NO: 39. In another aspect of this embodiment, a B-trefoil domain derived from a FGF-18 comprises amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. [0587] In another embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a modified p4/05 hairpin tum of a 0-trefoil domain of a FGF-18 or a modified 08/09 hairpin turn of a p-trefoil domain of a FGF-18 of SEQ ID NO: 39. In another aspect of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a modification of amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. [0588] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at least 75% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at least 80% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at least 85% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at least 90% amino acid identity with amino acids 92-94 or 255 of 316 WO 2006/101809 PCT/US2006/008956 amino acias 15-i/ OT btU lu 14u: .i or at least bo amino acia iaenuy wan amino acias Uz-U4 or amino acids 135-137 of SEQ ID NO: 39. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at most 75% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at most 80% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at most 85% amino acid Identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39, at most 90% amino acid identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39 or at most 95% amino acid Identity with amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. [0589] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF 18 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a non-contiguous amino acid substitution of any amino acid from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39 can be replaced with glycine. In other aspects of this embodiment, a non-contiguous amino acid substitution of any hydrophobic amino acid from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39 can be replaced with phenylalanine. In yet other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four non-contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 8 comprises a polypeptide having, e.g., at least one, two, three or four non-contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. [0590] In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid substitutions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this 256 of 316 WO 2006/101809 PCT/US2006/008956 emoodiment, contiguous amino acia suDsttutions ot amino acids tram amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39 can be replaced with glycine. In other aspects of this embodiment, contiguous amino acid substitutions of hydrophobic amino acids from amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39 can be replaced with phenylalanine. In yet other aspects of this embodiment, a 13-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-1 8 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid deletions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In still other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at most one, two, three or four contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ ID NO: 39. In other aspects of this embodiment, a B-trefoil domain with enhanced binding activity derived from a FGF-18 comprises a polypeptide having, e.g., at least one, two, three or four contiguous amino acid additions relative to amino acids 92-94 or amino acids 135-137 of SEQ iD NO: 39. [0591] Because of the modular nature of the 0-trefoil domain, it is envisioned that any combination of a folds, 0-folds, y-folds, 04/P5 p-hairpin tums, A8/09 0-hairpin turns, or any combination thereof from a p trefoil domain of a Clostridial toxin binding domain, a p-trefoil domain of a modified Clostridial toxin binding domain, a P-trefoii domain of a NAP or a p-trefoil domain, a p-trefoil domain of a modified NAP, a 0-trefoil domain of an FGF ligand, a 0-trefoil domain of a modified FGF ligand, or any combination thereof, can be used to practice aspect of the present invention. As a non-limiting example, a modified Clostridial toxin disclosed In the present specification can comprise an enhanced targeting domain comprising a a-fold from a BoNT/A binding domain, a 0-fold from a FGF-18 and a 2y-fold from a Clostridial botulinum serotype A HA-33. As another non-limiting example, a modified Clostridial toxin disclosed in the present specification can comprise an enhanced targeting domain comprising a a-fold from a Clostridial botulinum serotype A HA-17, a p-fold from a Clostridial botulinum serotype E NTNH and a y-fold from a modified BoNT/C1 binding domain with enhanced binding activity. [0592] In another aspect of the invention, a modified Clostridial toxin with enhanced binding activity comprises, in part, a protease cleavage site Is located within a di-chain loop region. As used herein, the term udi-chain loop region" means the amino acid sequence of a Clostridial toxin containing a protease cleavage site used to convert the single-chain form of a Clostridial toxin into the di-chain form. Non limiting examples of a Clostridial toxin di-chain loop region, include, a di-chain loop region of BoNT/A comprising amino acids 430-454 of SEQ ID NO: 1; a di-chain loop region of BoNT/B comprising amino acids 437-446 of SEQ ID NO: 2; a di-chain loop region of BoNT/C1 comprising amino acids 437-453 of SEQ ID NO: 3; a di-chain loop region of BoNT/D comprising amino acids 437-450 of SEQ ID NO: 4; a di chain loop region of BoNT/E comprising amino acids 412-426 of SEQ ID NO: 5; a di-chain loop region of BoNT/F comprising amino acids 429-445 of SEQ ID NO: 6; a di-chain loop region of BoNT/G comprising 257 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 436-450 of SEU. 1l) NU: 7; and a di-chain loop region o i eIN comprising amino acios 46ti 467 of SEQ ID NO: 8 (Table 8). Table 8. D1-chaIn Loop Region of Clostridial Toxins SEQ Light Chain 01-chain Loop Region Containing the Heavy Chain Toxin ID eg in Naturally-occurring Protease Cleavage Region NO: RenSiteR BoNT/A 1 NMNFTKLKNFTGLFEFYKLL CVRGllTSKTKSLDKGYNK*---ALNDLC IKVNNWDL BoNT/B 2 KQAYEEISKEHLAVYKIQM CKSVK*-------------APGIC IDVDNEDL BoNT/C1 3 PALRKVNPENMLYLFTKF CHKAIDGRSLYNK*---------TLDC RELLVKNTDL BoNTID 4 PALQKLSSESVVDLFTKV CLRLTKNSR*----------DDSTC IKVKNNRL BoNT/E 5 IITPITGRGLVKKIIRF CKNIVSVKGIR*-----------KSIC IEINNGEL BoNT/F 6 IIDSIPDKGLVEKIVKF CKSVIPRKGTK*--------APPRLC IRVNNSEL BoNT/G 7 KEAYEEISLEHLVIYRIAM CKPVMYKNTGK*---- -SEQC IIVNNEDL TeNT 8 TNAFRNVDGSGLVSKLIGL CKKIIPPTNIRENLYNRTA*SLTDLGGELC IKIKNEDL The amino acid sequence displayed are as follows: BoNT/A, residues 325-462 of SEQ ID No: 1; BoNT/B, residues 332-454 of SEQ ID No: 2; BoNT/C1, residues 334-463 of SEQ ID No: 3: BoNT/D, residues 334-458 of SEQ ID No: 4; BoNT/E, residues 311-434 of SEQ ID No: 5; BoNT/F, residues 328 453 of SEQ ID No: 6; BoNT/G, residues 331-458 of SEQ ID No: 7; and TeNT, residues 334-474 of SEQ ID No: 8. An asterisks (*) indicates the peptide bond that is cleaved by a Clostridial toxin protease. [05931 In is envisioned that any and all protease cleavage sites can be used to convert the single-chain polypeptide form of a Clostridial toxin into the di-chain form, including, without limitation, endogenous di chain loop protease cleavage sites and exogenous protease cleavage sites. (05941 As used herein, the term "endogenous di-chain loop protease cleavage site" is synonymous with a "naturally occurring di-chain loop protease cleavage site" and means a naturally occurring protease cleavage site found within the di-chain loop region of a naturally occurring Clostridial toxin and includes, without limitation, naturally occurring Clostridial toxin di-chain loop protease cleavage site variants, such as, e.g., Ciostridial toxin di-chain loop protease cleavage site isoforms and Clostridial toxin di-chain loop protease cleavage site subtypes. Non-limiting examples of an endogenous protease cleavage site, include, e.g., a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site and a TeNT di-chain loop protease cleavage site. [0595] As mentioned above, Clostridial toxins are translated as a single-chain polypeptide of approximately 150 kDa that is subsequently cleaved by proteolytic scission within a disulfide loop by a naturally-occurring protease. This posttranslational processing yields a di-chain molecule comprising an approximately 50 kDa light chain (LC) and an approximately 100 kDa heavy chain (HC) held together by a single disulphide bond and noncovalent interactions. While the Identity of the protease is currently 258 of 316 WO 2006/101809 PCT[US2006/008956 umuiwri, ine ai-cnain toop pruoeasi ulavage sie fur many Mlostnailai toxins nias oeen oeierminea. in BoNTs, cleavage at K448-A449 converts the single polypeptide form of BoNT/A into the di-chain form; cleavage at K441 -A442 converts the single polypeptide form of BoNT/B into the di-chain form; cleavage at K449-T450 converts the single polypeptide form of BoNT/Cl into the di-chain form; cleavage at R445 D446 converts the single polypeptide form of BoNT/D into the di-chain form; cleavage at R422-K423 converts the single polypeptide form of BoNT/E into the di-chain form; cleavage at K439-A440 converts the single polypeptide form of BoNT/F into the di-chain form; and cleavage at K446-S447 converts the single polypeptide form of BoNT/G Into the di-chain form. Proteolytic cleavage of the single polypeptide form of TeNT at A457-S458 results In the di-chain form. Such a di-chain loop protease cleavage site is operably-linked In-frame to a modified Clostridial toxin as a fusion protein. However, it should also be noted that additional cleavage sites within the di-chain loop also appear to be cleaved resulting in the generation of a small peptide fragment being lost. As a non-limiting example, BoNT/A single-chain polypeptide cleave ultimately results in the loss of a ten amino acid fragment within the di-chain loop. [0596] Thus, in an embodiment, a protease cleavage site comprising an endogenous Clostridial toxin di chain loop protease cleavage site is used to convert the single-chain toxin into the di-chain form. In aspects of this embodiment, conversion into the di-chain form by proteolytic cleavage occurs from a site comprising, e.g., a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site or a TeNT di-chain loop protease cleavage site. [0597] In other aspects of this embodiment, conversion into the di-chain form by proteolytic cleavage occurs from a site comprising, e.g., a di-chain loop region of BoNT/A comprising amino acids 430-454 of SEQ ID NO: 1; a di-chain loop region of BoNT/B comprising amino acids 437-446 of SEQ ID NO: 2; a di chain loop region of BoNT/C1 comprising amino acids 437-453 of SEQ ID NO: 3; a di-chain loop region of BoNT/D comprising amino acids 437-450 of SEQ ID NO: 4; a di-chain loop region of BoNT/E comprising amino acids 412-426 of SEQ ID NO: 5; a di-chain loop region of BoNT/F comprising amino acids 429-445 of SEQ ID NO: 6; a di-chain loop region of BoNT/G comprising amino acids 436-450 of SEQ ID NO: 7; or a di-chain loop region of TeNT comprising amino acids 439-467 of SEQ ID NO: 8. [0598] It is also envisioned that an exogenous protease cleavage site can be used to convert the single chain polypeptide form of a modified Clostridial toxin disclosed in the present specification into the di chain form. As used herein, the term "exogenous protease cleavage site" is synonymous with a "non naturally occurring protease cleavage site" and means a protease cleavage site that is not normally present in a di-chain loop region from a naturally occurring Clostridial toxin. Non-limiting examples of exogenous protease cleavage sites include, e.g., an enterokinase cleavage site (Table 9); a Thrombin cleavage site (Table 9); a Factor Xa cleavage site (Table 9); a human rhinovirus 3C protease cleavage site (Table 9); a tobacco etch virus (TEV) protease cleavage site (Table 9); a dipeptidy aminopeptidase 259 of 316 WO 2006/101809 PCTIUS2006/008956 cleavage site; a small ubiquitin-like modifier (SUMO)/ubiqutin-like protein-1(ULP-1) protease cleavage site, such as, e.g., MADSEVNQEAKPEVKPEVKPETHINLKVSDGSSEIFFKIKKTTPLRRLMEAFAKRQGK EMDSLRFLYDGIRIQADQTPEDLDMEDNDIIEAHREQIGG (SEQ ID. NO: 57); and a Clostridial toxin substrate cleavage site. Table 9. Exogenous Protease Cleavage Sites Protease Cleavage Consensus S eNon-limiting SEQ ID Site Examples NO: Bovine enterokinase DDDDK* DDDDK* 40 ENLYFQ*G 41 ENLYFQ*S 42 ENIYTQ*G 43 E Pr P4YP2Q*(G/S) ENIYTQ*S 44 Tobacco Etch Virus ENIYLQ*G 45 where P 2 , p 4 and Ps can be any amino acid ENIYLQ*S 46 ENVYFQ*G 47 ENVYSQ*S 49 ENVYSQ*G 49 ENVYSQ*S 50 EALFQ*GP 51 P5P 4 LFQ*GP EVLFQ*GP 52 ELLFQ*GP 53 Human Rhinovirus 3C where P 4 is G, A, V, L, I, M, S or T and Ps can any DALFQ*GP 54 amino acid, with D or E preferred. DVLFQ*GP 55 DLLFQ*GP 56 SUMO/ULP-1 Tertiary structure polypeptide-G* 57 pap 2 (R/K)*P' GVR*G 58 SAR*G 59 Thrombin where p3 is any amino acid and P2 or P" Is G with SLR*G 60 the other position being any amino acid QGK*I 62 LVPR*GS 63 LVPK*GS 64 p4psp(R/K)*Plp 2 ' FIPR*TF 65 VLPR*SF 66 where Pr and P 2 ' can be any amino acid except for IVPR*SF 67 Thrombin acidic amino acids like D or E; and P 3 and P4 are IVPR*GY 68 hydrophobic amino acids like F, L, I, Y, W, V, M, P, VVPR*GV 69 C or A VLPR*LI 70 VMPR*SL 71 MFPR*SL 72 Coagulation Factor Xa l(E/D)GR* IDGR* 73 CoaulaionIEGR* 74 An asterisks (*) indicates the peptide bond that is cleaved by the indicated protease. [0599] As mentioned above, a Clostridial toxin is converted from a single polypeptide form into a di-chain molecule by proteolytic cleavage. While the naturally-occurring protease is currently not known, cleavage occurs within the di-chain loop region between the two cysteine residues that form the disulfide bridge (see Table 8). Replacement of an endogenous protease cleavage site with an exogenous protease 260 of 316 WO 2006/101809 PCT/US2006/008956 cleavage site will enable cleavage of a modified Clostridial toxin disclosed in the present speclication when expressed in an organism that does not produce the naturally-occurring protease used to cleave the di-chain loop region of a toxin. Similarly, an addition of an exogenous protease cleavage site in the di-chain loop region will also enable cleavage of a modified Clostridial toxin disclosed in the present specification when expressed in an organism that does not produce the naturally-occurring protease used to cleave the di-chain loop region of a toxin. [0600] It is envisioned that an exogenous protease cleavage site of any and all lengths can be useful In aspects of the present invention with the proviso that the exogenous protease cleavage site Is capable of being cleaved by its respective protease. Thus, in aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at least 6 amino acids in length, at least 7 amino acids in length, at least 8 amino acids in length, at least 9 amino acids in length, at least 10 amino acids in length, at least 15 amino acids in length, at least 20 amino acids in length, at least 25 amino acids in length, at least 30 amino acids in length, at least 40 amino acids.in length, at least 50 amino acids in length or at least 60 amino acids in length. In other aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at most 6 amino acids in length, at most 7 amino acids in length, at most 8 amino acids In length, at most 9 amino acids in length, at most 10 amino acids in length, at most 15 amino acids in length, at most 20 amino acids in length, at most 25 amino acids in length, at most 30 amino acids in length, at most 40 amino acids in length, at most 50 amino acids in length or at most 60 amino acids in length. [0601] In aspects of this embodiment, a di-chain loop region can be modified to substitute a naturally occurring protease cleavage site for an exogenous protease cleavage site. In this type of modification, the naturally-occurring protease cleavage site is made inoperable and thus can not be cleaved by its protease. Only the exogenous protease cleavage site can be cleaved by its corresponding exogenous protease. In this type of modification, the exogenous protease site Is operably-linked in-frame to a modified Clostridial toxin as a fusion protein and the site can be cleaved by its respective exogenous protease. As a non-limiting example, a single-chain modified BoNT/A comprising an exogenous protease cleavage site in the di-chain loop region can be cleaved by its respective exogenous protease to produce the dI-chain form of the toxin. [0602] In other aspects of this embodiment, a di-chain loop region can be modified to include an exogenous protease cleavage site in addition to the naturally-occurring protease cleavage site. In this type of modification, both cleavage sites are operably-linked in-frame to a modified Clostridial toxin as a fusion protein and both sites can be cleaved by their respective proteases. As a non-limiting example, a single-chain modified BoNT/A that comprises a di-chain loop containing both the naturally-occurring BoNT/A di-chaln loop protease cleavage site and an exogenous protease cleavage site can be cleaved by either the naturally occurring di-chain loop protease or by the appropriate exogenous protease to produce the di-chain form of the toxin. 261 of 316 WO 2006/101809 PCT/US2006/008956 tuouJ m naturaiiy-omuumny piutiase cleavage sue can ve maae inoperaoie oy altering at least tne two amino acids flanking the peptide bond cleaved by the naturally-occurring di-chain loop protease. More extensive alterations can be made, with the proviso that the two cysteine residues of the di-chain loop region remain intact and can still form the disulfide bridge. Non-limiting examples of an amino acid alteration include deletion of an amino acid or replacement of the original amino acid with a different amino acid. Thus, In one embodiment, a naturally-occurring protease cleavage site is made inoperable by altering the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease. In other aspects of this embodiment, a naturally-occurring protease cleavage site is made inoperable by altering, e.g., at least three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least seven amino acids including the two amino acids flanking the peptide bond cleaved by a naturally occurring protease; at least eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at least 20 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally occurring protease. (0604] In still other aspects of this embodiment, a naturally-occurring di-chain protease cleavage site is made inoperable by altering, e.g., at most three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally occurring protease; at most seven amino acids Including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at most 20 amino acids Including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease. [06051 In an embodiment, an exogenous protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In aspects of this embodiment, a modified Clostridial toxin comprises an 262 of 316 WO 2006/101809 PCT/US2006/008956 exogenous protease cleavage site composes, e.g., -a bovine enterokinase protease cleavage site, a Tobacco Etch Virus protease cleavage site, a Human Rhinovirus 3C protease cleavage site, a SUMO/ULP-1 protease cleavage site, a Thrombin protease cleavage site or a Factor Xa protease cleavage site. In other aspects of this embodiment, an exogenous protease cleavage site Is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0606] In an aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a bovine enterokinase cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a bovine enterokinase protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 40. Is still other aspects of this embodiment, a bovine enterokinase protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0607] In another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Tobacco Etch Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49 or SEQ ID NO: 50. Is still other aspects of this embodiment, a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0608] In still another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Human Rhinovirus 3C protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Human Rhinovirus 3C protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55 or SEQ ID NO: 56. Is still other aspects of this embodiment, a Human Rhinovirus 3C protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0609] In yet another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a SUMO/ULP-1 protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a SUMO/ULP-1 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 57. Is still other aspects of this embodiment, a SUMO/ULP-1 protease cleavage site is located within 263 of 316 WO 2006/101809 PCT/US2006/008956 ine al-chain loop ot, e.g., a moarmea tOo04 I/A, a moditned 00N i l/, a moarmea bON I.ui, a moomfeo BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0610] In a further aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Thrombin protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Thrombin protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 70, SEQ ID NO: 71 or SEQ ID NO: 72. Is still other aspects of this embodiment, a Thrombin protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0611] In another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Coagulation Factor Xa protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Coagulation Factor Xa protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 73 or SEQ ID NO: 74. Is still other aspects of this embodiment, a Coagulation Factor Xa protease cleavage site Is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0612] In another embodiment, an exogenous protease site comprises a Clostridial toxin substrate cleavage site. As used herein, the term "Clostridial toxin substrate cleavage site" means a scissile bond together with adjacent or non-adjacent recognition elements, or both, sufficient for detectable proteolysis at the scissile bond by a Clostridial toxin under conditions suitable for Clostridial toxin protease activity. By definition, a Clostridial toxin substrate cleavage site is susceptible to cleavage by at least one Clostridial toxin under conditions suitable for Clostridial toxin protease activity. Non-limiting examples of Clostridial toxin substrate cleavage site are disclosed in, e.g., Steward, L.E. et al., Self-Activating Clostridial Toxins, U.S. Patent Application 60/718,616 (Sep, 19, 2005). [0613] It is understood that a modified Clostridial toxin disclosed in the present specification can optionally include one or more additional components. As a non-limiting example of an optional component, a modified Clostridial toxin can further comprise a flexible region comprising a flexible spacer. Non-limiting examples of a flexible spacer include, e.g., a G-spacer GGGGS (SEQ ID NO: 75) or an A spacer EAAAK (SEQ ID NO: 76). A flexible region comprising flexible spacers can be used to adjust the length of a polypeptide region in order to optimize a characteristic, attribute or property of a polypeptide. Such a flexible region is operably-linked in-frame to the modified Clostridlal toxin as a fusion protein. As a non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use 264 of 316 WO 2006/101809 PCTIUS2006/008956 to better expose a protease cleavage site thereby facilitating cleavage of that site by a protease. As another non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use to better present an enhanced targeting domain, thereby facilitating the binding of that enhanced targeting domain to its receptor system. [0614] Thus, in an embodiment, a modified Olostridial toxin disclosed In the present specification can further comprise a flexible region comprising a flexible spacer. In another embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise flexible region comprising a plurality of flexible spacers in tandem. In aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 G-spacer, at least 2 G-spacers, at least 3 G-spacers, at least 4 G-spacers or at least 5 G-spacers. In other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at most 1 G-spacer, at most 2 G-spacers, at most 3 G-spacers, at most 4 G-spacers or at most 5 G-spacers. In still other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 A spacer, at least 2 A-spacers, at least 3 A-spacers, at least 4 A-spacers or at least 5 A-spacers. In still other aspects of this embodiment, a flexible region can comprise In tandem, e.g., at most 1 A-spacer, at most 2 A-spacers, at most 3 A-spacers, at most 4 A-spacers or at most 5 A-spacers. In another aspect of this embodiment, a modified Clostridial toxin can comprise a flexible region comprising one or more copies of the same flexible spacers, one or more copies of different flexible-spacer regions, or any combination thereof. [0615] In aspects of this embodiment, a modified Clostridial toxin comprising a flexible spacer can be, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT. [0616] It is envisioned that a modified Clostridial toxin disclosed in the present specification can comprise a flexible spacer in any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. In aspects of this embodiment, a flexible spacer is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an enhanced targeting domain, an enzymatic domain and a protease cleavage site. In other aspects of this embodiment, a G-spacer Is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an enhanced targeting domain, an enzymatic domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an enhanced targeting domain, an enzymatic domain and a protease cleavage site. [0617] In other aspects of this embodiment, a flexible spacer is positioned between, e.g., an enhanced targeting domain and a translocation domain, an enhanced targeting domain and an enzymatic domain, an enhanced targeting domain and a protease cleavage site. In other aspects of this embodiment, a G spacer is positioned between, e.g., an enhanced targeting domain and a translocation domain, an 265 of 316 WO 2006/101809 PCTIUS2006/008956 enhanced targeting domain and an enzymatic domain, an enhanced targeting domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., an enhanced targeting domain and a translocation domain, an enhanced targeting domain and an enzymatic domain, an enhanced targeting domain and a protease cleavage site. [0618] In yet other aspects of this embodiment, a flexible spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an enhanced targeting domain, an translocation domain and a protease cleavage site. In other aspects of this embodiment, a G spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an enhanced targeting domain, an translocation domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an enhanced targeting domain, a translocation domain and a protease cleavage site. [06191 As another non-limiting example of an optional component, a modified Clostridial toxin can further comprise an epitope-binding region. An epitope-binding region can be used in a wide variety of procedures involving, e.g., protein purification and protein visualization. Such an epitope-binding region is operably-linked in-frame to a modified Ciostridial toxin as a fusion protein. Non-limiting examples of an epitope-binding region include, e.g., FLAG, ExpressTM (SEQ ID NO: 77), human Influenza virus hemagluttinin (HA) (SEQ ID NO: 78), human p 62 *"" protein (c-MYC) (SEQ ID NO: 79), Vesicular Stomatitis Virus Glycoprotein (VSV-G) (SEQ ID NO: 80), Substance P (SEQ ID NO: 81), glycoprotein-D precursor of Herpes simplex virus (HSV) (SEQ ID NO: 82), VS (SEQ ID NO: 83), AU1 (SEQ ID NO: 84) and AU5 (SEQ ID NO: 85); affinity-binding, such as. e.g., polyhistidine (HIS) (SEQ ID NO: 86), streptavidin binding peptide (strep), and biotin or a biotinylation sequence; peptide-binding regions, such as. e.g., the glutathione binding domain of glutathione-S-transferase, the calmodulin binding domain of the calmodulin binding protein, and the maltose binding domain of the maltose binding protein. Non limiting examples of specific protocols for selecting, making and using an appropriate binding peptide are described in, e.g., Epitope Tagging, pp. 17.90-17.93 (Sambrook and Russell, eds., Molecular Cloning A Laboratory Manual, Vol. 3, 3" ed. 2001); Antibodies: A Laboratory Manual (Edward Harlow & David Lane, eds., Cold Spring Harbor Laboratory Press, 2"d ed. 1998); and Using Antibodies: A Laboratory Manual: Portable Protocol No. I (Edward Harlow & David Lane, Cold Spring Harbor Laboratory Press, 1998). In addition, non-limiting examples of binding peptides as well as well-characterized reagents, conditions and protocols are readily available from commercial vendors that include, without limitation, BD Biosciences Clontech, Palo Alto, CA; BD Biosciences Pharmingen, San Diego, CA; Invitrogen, Inc, Carlsbad, CA; QIAGEN, Inc., Valencia, CA; and Stratagene, La Jolla, CA. These protocols are routine procedures well within the scope of one skilled in the art and from the teaching herein. [0620] Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise an epitope-binding region. In another embodiment, a modified Clostridia) toxin disclosed 266 of 316 WO 2006/101809 PCT/US2006/008956 in the present specification can further comprises a plurality of epitope-binding regions. In aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at least 1 epitope-binding region, at least 2 epitope-binding regions, at least 3 epitope-binding regions, at least 4 epitope-binding regions or at least 5 epitope-binding regions. In other aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at most 1 epitope-binding region, at most 2 epitope-binding regions, at most 3 epitope-binding regions, at most 4 epitope-binding regions or at most 5 epitope-binding regions. In another aspect of this embodiment, a modified Clostridial toxin can comprise one or more copies of the same epitope-binding region, one or more copies of different epitope-binding regions, or any combination thereof. (0621] The location of an epitope-binding region can be in various positions, Including, without limitation, at the amino terminus of a modified Clostridial toxin, within a modified Clostridial toxin, or at the carboxyl terminus of a modified Clostridial toxin. Thus, in an embodiment, an epitope-binding region is located at the amino-terminus of a modified Clostridial toxin. In such a location, a start methionine should be placed in front of the epitope-binding region. In addition, it is known in the art that when adding a polypeptide that is operationally-linked to the amino terminus of another polypeptide comprising the start methionine that the original methionine residue can be deleted. This is due to the fact that the added polypeptide will contain a new start methionine and that the original start methionine may reduce optimal expression of the fusion protein. In aspects of this embodiment, an epitope-binding region located at the amino terminus of a modified Clostridial toxin disclosed in the present specification can be, e.g., a FLAG, Expresswm opitope-binding region, a human Influenza virus hemagluttinin (HA) epitope-binding region, a human p62""m" protein (c-MYC) epitope-binding region, a Vesicular Stomatitis Virus Glycoprotein (VSV G) epitope-binding region, a Substance P epitope-binding region, a glycoprotein-D precursor of Herpes simplex virus (HSV) epitope-binding region, a V5 epitope-binding region, a AU1 epitope-binding region, a AUS epitope-binding region, a polyhistidine epitope-binding region, a streptavidin binding peptide epitope binding region, a biotin epitope-binding region, a biotinylation epitope-binding region, a glutathlone binding domain of glutathlone-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein. [0622] In another embodiment, an epitope-binding region is located at the carboxyl-terminus of a modified Clostridial toxin. In aspects of this embodiment, an epitope-binding region located at the carboxyl-terminus of a modified Clostridial toxin disclosed In the present specification can be, e.g., a FLAG, Express TM epitope-binding region, a human Influenza virus hemagluttinin (HA) epitope-binding region, a human p62'"Yc protein (c-MYC) epitope-binding region, a Vesicular Stomatitis Virus Glycoprotein (VSV-G) epitope-binding region, a Substance P epitope-binding region, a glycoprotein-D precursor of Herpes simplex virus (HSV) epitope-binding region, a V5 epitope-binding region, a AU1 epitope-binding region, a AUS epitope-binding region, a polyhistidine epitope-binding region, a streptavidin binding peptide epitope-binding region, a biotin epitope-binding region, a biotinylation epitope-binding region, a glutathione binding domain of glutathione-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein. 267 of 316 WO 2006/101809 PCT/US2006/008956 [0623] It is envisioned that a modified Clostridial toxin disclosed In the present specification can comprise an enhance binding domain In any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. Non-limiting examples include, locating an enhance binding domain at the amino terminus of a modified Clostridial toxin (FIG. 3); locating an enhance binding domain between a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain of a modified Clostridial toxin (FIG. 4); and locating an enhance binding domain at the carboxyl terminus of a modified Clostridial toxin (FIG. 5). [0624] Thus, in an embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and an enhanced targeting domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a protease cleavage site, a Clostridial toxin translocation domain and an enhanced targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an endogenous protease cleavage site, a Clostridial toxin translocation domain and an enhanced targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a Clostridial toxin translocation domain and an enhanced targeting domain. [06251 In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an enhanced targeting domain and a Clostridial toxin translocation domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a protease cleavage site, an enhanced targeting domain and a Clostridial toxin translocation domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an endogenous protease cleavage site, an enhanced targeting domain and a Clostridial toxin translocation domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, an enhanced targeting domain and a Clostridial toxin translocation domain. [0626] In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin translocation domain, and a Clostridial toxin enzymatic domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin translocation domain, a protease cleavage site and a Clostridial toxin enzymatic domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an 268 of 316 WO 2006/101809 PCT/US2006/008956 amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin translocation domain, an endogenous protease cleavage site and a Clostridial toxin enzymatic domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin translocation domain, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain. [0627] In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin enzymatic domain, a protease cleavage site and a Clostridial toxin translocation domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin enzymatic domain, an endogenous protease cleavage site and a Clostridial toxin translocation domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an enhanced targeting domain, a Clostridial toxin enzymatic domain, an exogenous protease cleavage site and a Clostridial toxin translocation domain. [0628] In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a Clostridial toxin enzymatic domain and an enhanced targeting domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a protease cleavage site, a Clostridial toxin enzymatic domain and an enhanced targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, an endogenous protease cleavage site, a Clostridial toxin enzymatic domain and an enhanced targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, an exogenous protease cleavage site, a Clostridial toxin enzymatic domain and an enhanced targeting domain. [0629] Aspects of the present invention provide, in part modified Clostridial toxins. Non-limiting examples of Clostridial toxin modifications disclosed in the present specification include, e.g., addition of an enhanced targeting domain, addition of a protease cleavage site, rearrangement of the enzymatic, translocation and binding domains and addition of a spacer region. It is understood that all such modifications do not substantially affect the ability of a modified Clostridial toxin to intoxicate a cell. As used herein, the term "do not substantially affect means a modified Clostridial toxin can still execute the overall cellular mechanism whereby a Clostridial toxin enters a neuron and inhibits neurotransmitter release and encompasses the binding of a Clostridial toxin to a low or high affinity receptor complex, the internalization of the toxin/receptor complex, the translocation of the Clostridial toxin light chain into the 269 of 316 WO 2006/101809 PCT/US2006/008956 cytoplasm and the enzymatic modification of a Clostridial toxin substrate. In aspects of this embodiment, the modified Clostridial toxin is, e.g., at least 10% as toxic as a naturally-occurring Clostridial toxin, at least 20% as toxic as a naturally-occurring Clostridial toxin, at least 30% as toxic as a naturally-occurring Clostridial toxin, at least 40% as toxic as a naturally-occurring Clostridial toxin, at least 50% as toxic as a naturally-occurring Clostridial toxin, at least 60% as toxic as a naturally-occurring Clostridial toxin, at least 70% as toxic as a naturally-occurring Clostridial toxin, at least 80% as toxic as a naturally-occurring Clostridial toxin, at least 90% as toxic as a naturally-occurring Clostridlal toxin or at least 95% as toxic as a naturally-occurring Clostridial toxin. In aspects of this embodiment, the modified Clostridial toxin is, e.g., at most 10% as toxic as a naturally-occurring Clostridlal toxin, at most 20% as toxic as a naturally occurring Clostridial toxin, at most 30% as toxic as a naturally-occurring Clostridial toxin, at most 40% as toxic as a naturally-occurring Clostridial toxin, at most 50% as toxic as a naturally-occurring Clostridial toxin, at most 60% as toxic as a naturally-occurring Clostridial toxin, at most 70% as toxic as a naturally occurring Clostridial toxin, at most 80% as toxic as a naturally-occurring Clostridial toxin, at most 90% as toxic as a naturally-occurring Clostridial toxin or at most 95% as toxic as a naturally-occurring Clostridial toxin. [0630] Another aspect of the present invention provides polynucleotide molecules encoding modified Clostridial toxins disclosed in the present specification. It is envisioned that any and all modified Clostridial toxin disclosed in the present specification can be encoded by a polynucleotide molecule. [0631] Aspects of the present invention provide, in part polynucleotide molecules. As used herein, the term "polynucleotide molecule" is synonymous with "nucleic acid molecule" and means a polymeric form of nucleotides, such as, e.g., ribonucleotides and deoxyribonucleotides, of any length. It is envisioned that any and all polynucleotide molecules that can encode a modified Clostridial toxin disclosed in the present specification can be useful, Including, without limitation naturally-occurring and non-naturally occurring DNA molecules and naturally-occurring and non-naturally-occurring RNA molecules. Non limiting examples of naturally-occurring and non-naturally-occurring DNA molecules include single stranded DNA molecules, double-stranded DNA molecules, genomic DNA molecules, cDNA molecules, vector constructs, such as, e.g., plasmid constructs, phagmid constructs, bacteriophage constructs, retroviral constructs and artificial chromosome constructs. Non-limiting examples of naturally-occurring and non-naturally-occurring RNA molecules include single-stranded RNA, double stranded RNA and mRNA. [0632] Thus, In an embodiment, a polynucleotide molecule encodes a modified Clostridial toxin disclosed in the present specification. [0633] In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising a Clostridial toxin enzymatic domain disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a modified Clostridial toxin enzymatic domain 270 of 316 WO 2006/101809 PCT/US2006/008956 comprises a naturally occurring Clostridial toxin enzymatic domain variant, such as, e.g., a Clostridial toxin enzymatic domain isoform or a Clostridial toxin enzymatic domain subtype. In another aspect of this embodiment, a polynucleotide molecule encoding a Clostridial toxin enzymatic domain comprises a non naturally occurring Clostridial toxin enzymatic domain variant, such as, e.g., a conservative Clostridlal toxin enzymatic domain variant, a non-conservative Clostridial toxin enzymatic domain variant or an active Clostridial toxin enzymatic domain fragment, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a Clostridial toxin enzymatic domain comprises a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain, a TeNT enzymatic domain, or active fragment thereof. [0634] In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising a Clostridial toxin translocation domain disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a modified Clostridial toxin translocation domain comprises a naturally occurring Clostridial toxin translocation domain variant, such as, e.g., a Clostridial toxin translocation domain isoform or a Clostridial toxin translocation domain subtype. In another aspect of this embodiment, a polynucleotide molecule encoding a Clostridial toxin translocation domain comprises a non-naturally occurring Clostridial toxin translocation domain variant, such as, e.g., a conservative Clostridial toxin translocation domain variant, a non-conservative Clostridial toxin translocation domain variant or an active Clostridial toxin translocation domain fragment, or any combination thereof. in other aspects of this embodiment, a polynucleotide molecule encoding a Clostridial toxin translocation domain comprises a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain, a TeNT translocation domain, or active fragment thereof. [06351 in another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising an enhanced targeting domain disclosed in the present specification. in an aspect of this embodiment, a polynucleotide molecule encoding an enhanced targeting domain comprises a Clostridial toxin binding domain with enhanced binding activity disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a modified Clostridial toxin binding domain with enhanced binding activity comprises a non-naturally occurring Clostridial toxin binding domain variant with enhanced binding activity, such as, e.g., a conservative Clostridial toxin binding domain variant with enhanced binding activity, a non-conservative Clostridial toxin binding domain variant with enhanced binding activity or an active Clostridial toxin binding domain fragment with enhanced binding activity, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a Clostridial toxin binding domain with enhanced binding activity comprises a BoNT/A binding domain with enhanced binding activity, a BoNT/B binding domain with enhanced binding activity, a BoNT/C1 binding domain with enhanced binding activity, a BoNT/D binding domain with enhanced binding activity, a 271 of 316 WO 2006/101809 PCT/US2006/008956 BoNT/E binding domain with enhanced binding activity, a BoNT/F binding domain with enhanced binding activity, a BoNT/G binding domain with enhanced binding activity, a TeNT binding domain with enhanced binding activity, or active fragment thereof. [0636]' In an aspect of this embodiment, an enhanced targeting domain comprises a Clostridial NAP disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a Clostridial NAP comprises a naturally occurring Clostridial NAP variant, such as, e.g., a Clostridial NAP isoform or a Clostridial NAP subtype. In an aspect of this embodiment, a polynucleotide molecule encoding a NAP comprises a non-naturally occurring Clostridial NAP variant, such as, e.g., a conservative Clostridial NAP variant, a non-conservative Clostridial NAP variant or an active Clostridial NAP fragment, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a Clostridial NAP comprises a Clostridial botulinum serotype A HA-33, a Clostridial botulinum serotype B HA-33, a Clostridial botulinum serotype C1 HA-33, a Clostridial botulinum serotype D HA-33, a Clostridial botulinum serotype A HA-17, a Clostridial botulinum serotype B HA-17, a Clostridial botulinum serotype C1 HA-17, a Clostridial botulinum serotype D HA-17, a Ciostridial botulinum serotype A NTNH, a Clostridial botulinum serotype B NTNH, a Clostridial botulinum serotype C1 NTNH, a Clostridial botulinum serotype D NTNH, a Clostridial botulinum serotype E NTNH, a Clostridial botulinum serotype F NTNH and a Clostridial botulinum serotype G NTNH. [0637] In an aspect of this embodiment, an enhanced targeting domain comprises a Clostridial NAP with enhanced binding activity disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a NAP with enhanced binding activity comprises a non-naturally occurring Clostridial NAP variant with enhanced binding activity, such as, e.g., a conservative Clostridial NAP variant with enhanced binding activity, a non-conservative Clostridial NAP variant with enhanced binding activity or an active Clostridial NAP fragment with enhanced binding activity, or any combination thereof. in other aspects of this embodiment, a polynucleotide molecule encoding a Clostridial NAP comprises a Clostridial botulinum serotype A HA-33 with enhanced binding activity, a Ciostridial botulinum serotype B HA-33 with enhanced binding activity, a Ciostridial botulinum serotype C1 HA-33 with enhanced binding activity, a Clostridial botulinum serotype D HA-33 with enhanced binding activity, a Clostridial botulinum serotype A HA-17 with enhanced binding activity, a Clostridial botulinum serotype B HA-17 with enhanced binding activity, a Clostridial botulinum serotype C1 HA-17 with enhanced binding activity, a Clostridial botulinum serotype D HA-17 with enhanced binding activity, a Clostridial botulinum serotype A NTNH with enhanced binding activity, a Clostridial botulinum serotype B NTNH with enhanced binding activity, a Clostridial botulinum serotype C1 NTNH with enhanced binding activity, a Clostridial botulinum serotype D NTNH with enhanced binding activity, a Clostridial botulinum serotype E NTNH with enhanced binding activity, a Clostridial botulinum serotype F NTNH with enhanced binding activity and a Clostridial botulinum serotype G NTNH with enhanced binding activity. 272 of 316 WO 2006/101809 PCT/US2006/008956 [0638] In an aspect of this embodiment, an enhanced targeting domain comprises a FGF disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a FGF comprises a naturally occurring FGF variant, such as, e.g., a FGF isoform or a FGF subtype. In an aspect of this embodiment, a polynucleotide molecule encoding a FGF comprises a non-naturally occurring FGF variant, such as, e.g., a conservative FGF variant, a non-conservative FGF variant or an active FGF fragment, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a FGF comprises a FGF-1, a FGF-2, a FGF-4, a FGF-8, a FGF-9, a FGF-17 and a FGF-18. [0639] In an aspect of this embodiment, an enhanced targeting domain comprises a FGF with enhanced binding activity disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a FGF with enhanced binding activity comprises a non-naturally occurring FGF variant with enhanced binding activity, such as, e.g., a conservative FGF variant with enhanced binding activity, a non-conservative FGF variant with enhanced binding activity or an active FGF fragment with enhanced binding activity, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a FGF with enhanced binding activity comprises a FGF-1 with enhanced binding activity, a FGF-2 with enhanced binding activity, a FGF-4 with enhanced binding activity, a FGF-8 with enhanced binding activity, a FGF-9 with enhanced binding activity, a FGF-17 with enhanced binding activity and a FGF-1 8 with enhanced binding activity. [0640] In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising a protease cleavage site disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a protease cleavage site comprises an endogenous Clostridial toxin protease site. In aspects of this embodiment, a polynucleotide molecule encoding an endogenous Clostridial toxin protease site can be, e.g., a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site or a TeNT di-chain loop protease cleavage site. In another aspect of this embodiment, a polynucleotide molecule encoding a protease cleavage site comprises an exogenous Clostridial toxin protease site. In aspects of this embodiment, a polynucleotide molecule encoding an exogenous Clostridial toxin protease site can be, e.g., a bovine enterokinase protease cleavage site, a Tobacco Etch Virus protease cleavage site, a Human Rhinovirus 3C protease cleavage site, a SUMO/ULP-1. protease cleavage site, a Thrombin protease cleavage site, a Coagulation Factor Xa protease cleavage site or a Clostridial toxin substrate cleavage site, such as, e.g., a BoNT/A substrate cleavage site, a BoNT/B substrate cleavage site, a BoNT/Cl substrate cleavage site, a BoNT/D substrate cleavage site, a BoNT/E substrate cleavage site, a BoNT/F substrate cleavage site, a BoNT/G substrate cleavage site or a TeNT substrate cleavage site. 273 of 316 WO 2006/101809 PCT/US2006/008956 [0641] In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising a flexible spacer disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a flexible spacer can comprise a G-spacer, a A-spacer or any combination thereof. [0642] In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising an epitope-binding region disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding an epitope-binding region can comprise a FLAG, ExpressTM, a human Influenza virus hemagluttinin (HA), a human p62*** protein (c-MYC), a Vesicular Stomatitis Virus Glycoprotein (VSV-G), a Substance P, a glycoprotein-D precursor of Herpes simplex virus (HSV), a V5, a AU1, a AU5 (SEQ ID NO: 85), a polyhistidine (HIS), or any combination thereof. [0643] Well-established molecular biology techniques that may be necessary to make a polynucleotide molecule encoding a modified Clostridial toxin disclosed in the present specification including, but not limited to, procedures involving polymerase chain reaction (PCR) amplification, restriction enzyme reactions, agarose gel electrophoresis, nucleic acid ligation, bacterial transformation, nucleic acid purification, nucleic acid sequencing and recombination-based techniques are routine procedures well within the scope of one skilled in the art and from the teaching herein. Non-limiting examples of specific protocols necessary to make a polynucleotide molecule encoding a modified Clostridial toxin are described in e.g., MOLECULAR CLONING A LABORATORY MANUAL, supra, (2001); and CURRENT PROTOCOLS IN MOLECULAR BIOLOGY (Frederick M. Ausubel et al., eds. John Wiley & Sons, 2004). Additionally, a variety of commercially available products useful for making a polynucleotide molecule encoding a modified Clostridial toxin are widely available. These protocols are routine procedures well within the scope of one skilled in the art and from the teaching herein. [0644] Another aspect of the present invention provides a method of producing a modified Clostridial toxin disclosed in the present specification, such method comprising the step of expressing a polynucleotide molecule encoding a modified Clostridial toxin in a cell. Another aspect of the present invention provides a method of producing a modified Clostridial toxin disclosed in the present specification, such method comprising the steps of introducing an expression construct comprising a polynucleotide molecule encoding a modified Clostridial toxin into a cell and expressing the expression construct in the cell. [0645] The methods disclosed in the present specification include, in part, a modified Clostridial toxin. It Is envisioned that any and all modified Clostridlal toxins disclosed in the present specification can be produced using the methods disclosed in the present specification. It is also envisioned that any and all polynucleotide molecules encoding a modified Clostridial toxins disclosed in the present specification can be useful in producing a modified Clostridial toxins disclosed in the present specification using the methods disclosed in the present specification. 274 of 316 WO 2006/101809 PCT/US2006/008956 [0646] The methods disclosed In the present specification include, in part, an expression construct. An expression construct comprises a polynucleotide molecule disclosed In the present specification operably-linked to an expression vector useful for expressing the polynucleotide molecule in a cell or cell free extract. A wide variety of expression vectors can be employed for expressing a polynucleotide molecule encoding a modified Clostridial toxin, including, without limitation, a viral expression vector; a prokaryotic expression vector; eukaryotic expression vectors, such as, e.g., a yeast expression vector, an Insect expression vector and a mammalian expression vector; and a cell-free extract expression vector. It is further understood that expression vectors useful to practice aspects of these methods may include those which express a modified Clostridial toxin under control of a constitutive, tissue-specific, cell specific or inducible promoter element, enhancer element or both. Non-limiting examples of expression vectors, along with well-established reagents and conditions for making and using an expression construct from such expression vectors are readily available from commercial vendors that include, without limitation, BD Biosciences-Clontech, Palo Alto, CA; BD Biosciences Pharmingen, San Diego, CA; Invitrogen, Inc, Carlsbad, CA; EMD Biosciences-Novagen, Madison, WI; QIAGEN, Inc., Valencia, CA; and Stratagene, La Jolla, CA. The selection, making and use of an appropriate expression vector are routine procedures well within the scope of one skilled in the art and from the teachings herein. [0647] Thus, aspects of this embodiment include, without limitation, a viral expression vector operably linked to a polynucleotide molecule encoding a modified Clostridial toxin; a prokaryotic expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; a yeast expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; an insect expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; and a mammalian expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin. Other aspects of this embodiment include, without limitation, expression constructs suitable for expressing a modified Clostridial toxin disclosed In the present specification using a cell-free extract comprising a cell-free extract expression vector operably linked to a polynucleotide molecule encoding a modified Clostridial toxin. Other aspects of this embodiment include, without limitation, expression constructs comprising polynucleotide molecules comprising any one of SEQ ID NO: 109 through SEQ ID NO: 132 and SEQ ID NO: 136 through SEQ ID NO: 159. Other aspects of this embodiment include, without limitation, expression constructs comprising polynucleotide molecules encoding a modified Clostridial toxin comprising any one of SEQ ID NO: 85 through SEQ ID NO: 108. [06481 The methods disclosed in the present specification include, In part, a cell. It is envisioned that any and all cells can be used. Thus, aspects of this embodiment include, without limitation, prokaryotic cells including, without limitation, strains of aerobic, microaerophilic, capnophilic, facultative, anaerobic, gram-negative and gram-positive bacterial cells such as those derived from, e.g., Escherchia coll, Bacillus subtilis, Bacillus licheniformis, Bacteroides fragilis, Clostridia pertringens, Clostridia difficile, Caulobacter crescentus, Lactococcus lactis, Methylobacterium extorquens, Nelsseria meningirulls, 275 of 316 WO 2006/101809 PCT/US2006/008956 Neisseria meningitidis, Pseudomonas fluorescens and Salmonella typhimurium; and eukaryotic cells Including, without limitation, yeast strains, such as, e.g., those derived from Pichia pastors, Pichia methanolica, Pichia angusta, Schizosaccharomyces pombe, Saccharomyces cerevisiae and Yarrowia lipolytica; insect cells and cell lines derived from Insects, such as, e.g., those derived from Spodoptera frugiperda, Trichoplusia ni, Drosophila melanogaster and Manduca sexta; and mammalian cells and cell lines derived from mammalian cells, such as, e.g., those derived from mouse, rat, hamster, porcine, bovine, equine, primate and human. Cell lines may be obtained from the American Type Culture Collection, European Collection of Cell Cultures and the German Collection of Microorganisms and Cell Cultures. Non-limiting examples of specific protocols for selecting, making and using an appropriate cell line are described in e.g., INSECT CELL CULTURE ENGINEERING (Mattheus F. A. Goosen et al. eds., Marcel Dekker, 1993); INSECT CELL CULTURES: FUNDAMENTAL AND APPLIED ASPECTS (J. M. Vlak et al. eds., Kluwer Academic Publishers, 1996); Maureen A. Harrison & Ian F. Rae, GENERAL TECHNIQUES OF CELL CULTURE (Cambridge University Press, 1997); CELL AND TISSUE CULTURE: LABORATORY PROCEDURES (Alan Doyle et al eds., John Wiley and Sons, 1998); R. Ian Freshney, CULTURE OF ANIMAL CELLS: A MANUAL OF BASIC TECHNIQUE (Wiley-Liss, 4 1h ed. 2000); ANIMAL CELL CULTURE: A PRACTICAL APPROACH (John R. W. Masters ed., Oxford University Press, 3 ed. 2000); MOLECULAR CLONING A LABORATORY MANUAL, supm, (2001); BASIC CELL CULTURE: A PRACTICAL APPROACH (John M. Davis, Oxford Press, 2"a ed. 2002); and CURRENT PROTOCOLS IN MOLECULAR BIOLOGY, supra, (2004). These protocols are routine procedures within the scope of one skilled In the art and from the teaching herein. [0649] The methods disclosed in the present specification include, in part, introducing into a cell a polynucleotide molecule. A polynucleotide molecule introduced into a cell can be transiently or stably maintained by that cell. Stably-maintained polynucleotide molecules may be extra-chromosomal and replicate autonomously, or they may be integrated into the chromosomal material of the cell and replicate non-autonomously. It is envisioned that any and all methods for introducing a polynucleotide molecule disclosed in the present specification into a cell can be used. Methods useful for introducing a nucleic acid molecule into a cell include, without limitation, chemical-mediated transfection such as, e.g., calcium phosphate-mediated, diethyl-aminoethyl (DEAE) dextran-mediated, lipid-mediated, polyethyleneimine (PEI)-mediated, polylysine-mediated and polybrene-mediated; physical-mediated tranfection, such as, e.g., biolistic particle delivery, microinjection, protoplast fusion and electroporation; and viral-mediated transfection, such as, e.g., retroviral-mediated transfection, see, e.g., Introducing Cloned Genes into Cultured Mammalian Cells, pp. 16.1-16.62 (Sambrook & Russell, eds., Molecular Cloning A Laboratory Manual, Vol. 3, 3rd ed. 2001). One skilled in the art understands that selection of a specific method to introduce an expression construct into a cell will depend, in part, on whether the cell will transiently contain an expression construct or whether the cell will stably contain an expression construct. These protocols are routine procedures within the scope of one skilled in the art and from the teaching herein. [0650] In an aspect of this embodiment, a chemical-mediated method, termed transfection, is used to introduce a polynucleotide molecule encoding a modified Clostridial toxin into a cell. In chemical 276 of 316 WO 2006/101809 PCTIUS2006/008956 mediated methods of transfection the chemical reagent forms a complex with the nuclelc acid that facilitates its uptake into the cells. Such chemical reagents include, without limitation, calcium phosphate mediated, see, e.g., Martin Jordan & Florlan Worm, Transfection of adherent and suspended cells by calcium phosphate, 33(2) Methods 136-143 (2004); diethyl-aminoethyl (DEAE) dextran-mediated, lipid mediated, cationic polymer-mediated like polyethylenelmlne (PEI)-mediated and polylysine-medlated and polybrene-mediated, see, e.g., Chun Zhang at al., Polyethylenimine strategies for plasmid delivery to brain-derived cells, 33(2) Methods 144-150 (2004). Such chemical-mediated delivery systems can be prepared by standard methods and are commercially available, see, e.g., CellPhect Transfection Kit (Amersham Biosciences, Piscataway, NJ); Mammalian Transfection Kit, Calcium phosphate and DEAE Dextran, (Stratagene, Inc., La Jolla, CA); LipofectamineTM Transfection Reagent (Invitrogen, Inc., Carlsbad, CA); ExGen 500 Transfection kit (Fermentas, Inc., Hanover, MD), and SuperFect and Effectene Transfection Kits (Qiagen, Inc., Valencia, CA). [0651] In another aspect of this embodiment, a physical-mediated method is used to introduce a polynucleotide molecule encoding a modified Clostridial toxin into a cell. Physical techniques include, without limitation, electroporation, biolistic and microinjection. Biolistics and microinjection techniques perforate the cell wall in order to introduce the nucleic acid molecule into the cell, see, e.g., Jeike E. Biewenga at al., Plasmid-mediated gene transfer in neurons using the biolistics technique, 71(1) J. Neurosci. Methods. 67-75 (1997); and John O'Brien & Sarah C. R. Lummis, Biolistic and diolistic transfection: using the gene gun to deliver DNA and lipophilic dyes into mammalian cells, 33(2) Methods 121-125 (2004). Electroporation, also termed electropermeabilization, uses brief, high-voltage, electrical pulses to create transient pores in the membrane through which the nucleic acid molecules enter and can be used effectively for stable and transient transfections of all cell types, see, e.g., M. Golzio et al., In vitro and in vivo electric field-mediated permeabilization, gene transfer, and expression, 33(2) Methods 126 135 (2004); and Oliver Greschet al., New non-viral method for gene transfer into primary cells, 33(2) Methods 151-163 (2004). [0652] In another aspect of this embodiment, a viral-medlated method, termed transduction, is used to introduce a polynucleotide molecule encoding a modified Clostridial toxin into a cell. In viral-mediated methods of transient transduction, the process by which viral particles infect and replicate in a host cell has been manipulated in order to use this mechanism to Introduce a nucleic acid molecule into the cell. Viral-mediated methods have been developed from a wide variety of viruses including, without limitation, retroviruses, adenoviruses, adeno-associated viruses, herpes simplex viruses, picomaviruses, alphaviruses and baculoviruses, see, e.g., Armin Blesch, Lentiviral and MLV based retroviral vectors for ex vivo and in vivo gene transfer, 33(2) Methods 164-172 (2004); and Maurizio Federico, From lentiviruses to lentivirus vectors, 229 Methods Mol. BIol. 3-15 (2003); E. M. Poeschla, Non-primate lentiviral vectors, 5(5) Curr. Opin. Mol. Ther. 529-540 (2003); Karim Benihoud at al, Adenovirus vectors for gene delivery, 10(5) Curr. Opin. Biotechnol. 440-447 (1999); H. Bueler, Adeno-associated viral vectors for gene transfer and gene therapy, 380(6) Biol. Chem. 613-622 (1999); Chooi M. Lai et al., Adenovirus 277 of 316 WO 2006/101809 PCT/US2006/008956 and adeno-associated virus vectors, 21(12) DNA Cell Biol. 895-913 (2002); Edward A. Burton et al., Gene delivery using herpes simplex virus vectors, 21(12) DNA Cell Biol. 915-936 (2002); Paola Grandi et al., Targeting HSV amplicon vectors, 33(2) Methods 179-186 (2004); Ilya Frolov et al., Alphavirus-based expression vectors: strategies and applications, 93(21) Proc. Nati. Acad. Sci. U. S. A. 11371-11377 (1996); Markus U. Ehrengruber, Alphaviral gene transfer in neurobiology, 59(1) Brain Res. Bull. 13-22 (2002); Thomas A. Kost & J. Patrick Condreay, Recombinant baculoviruses as mammalian cell gene delivery vectors, 20(4) Trends Biotechnol. 173-180 (2002); and A. Huser & C. Hofmann, Baculovirus vectors: novel mammalian cell gene-delivery vehicles and their applications, 3(1) Am. J. Pharmacogenomics 53-63 (2003). 10653] Adenoviruses, which are non-enveloped, double-stranded DNA viruses, are often selected for mammalian cell transduction because adenoviruses handle relatively large polynucleotide molecules of about 36 kb, are produced at high titer, and can efficiently infect a wide variety of both dividing and non dividing cells, see, e.g., Wim T. J. M. C. Hermens et al., Transient gene transfer to neurons and glia: analysis of adenoviral vector performance in the CNS and PNS, 71(1) J. Neuroscl. Methods 85-98 (1997); and Hiroyuki Mizuguchi et al., Approaches for generating recombinant adenovirus vectors, 52(3) Adv. Drug Deliv. Rev. 165-176 (2001). Transduction using adenoviral-based system do not support prolonged protein expression because the nucleic acid molecule is carried from an episome in the cell nucleus, rather than being integrated into the host cell chromosome. Adenoviral vector systems and specific protocols for how to use such vectors are disclosed In, e.g., ViraPowerTM Adenoviral Expression System (Invitrogen, Inc., Carlsbad, CA) and ViraPowerTm Adenoviral Expression System Instruction Manual 25 0543 version A, Invitrogen, Inc., (Jul. 15, 2002); and AdEasyTM Adenoviral Vector System (Stratagene, Inc., La Jolla, CA) and AdEasyTM Adenoviral Vector System Instruction Manual 064004f, Stratagene, Inc.. [0654] Nucleic acid molecule delivery can also use single-stranded RNA retroviruses, such as, e.g., oncoretroviruses and lentiviruses. Retroviral-mediated transduction often produce transduction efficiencies close to 100%, can easily control the proviral copy number by varying the multiplicity of Infection (MOI), and can be used to either transiently or stably transduce cells, see, e.g., Tiziana Tonini et al., Transient production of retroviral- and lentiviral-based vectors for the transduction of Mammalian cells, 285 Methods Mol. Biol. 141-148 (2004); Armin Blesch, Lentiviral and MLV based retroviral vectors for ex vivo and in vivo gene transfer, 33(2) Methods 164-172 (2004); Felix Recillas-Targa, Gene transfer and expression In mammalian cell lines and transgenic animals, 267 Methods Mol. Blol. 417-433 (2004); and Roland Wolkowlcz et al., Lentiviral vectors for the delivery of DNA into mammalian cells, 246 Methods Mol. Biol. 391-411 (2004). Retroviral particles consist of an RNA genome packaged in a protein capsid, surrounded by a lipid envelope. The retrovirus infects a host cell by injecting its RNA into the cytoplasm along with the reverse transcriptase enzyme. The RNA template is then reverse transcribed Into a linear, double stranded cDNA that replicates itself by integrating into the host cell genome. Viral particles are spread both vertically (from parent cell to daughter cells via the provirus) as well as horizontally (from cell to cell via virions). This replication strategy enables long-term persistent expression since the nucleic 278 of 316 WO 2006/101809 PCT/US2006/008956 acid molecules of interest are stably integrated into a chromosome of the host cell, thereby enabling long term expression of the protein. For Instance, animal studies have shown that lentiviral vectors injected Into a variety of tissues produced sustained protein expression for more than 1 year, see, e.g., Luigi Naldini et al., In vivo gene delivery and stable transduction of non-dividing cells by a lentiviral vector, 272(5259) Science 263-267 (1996). The Oncoretroviruses-derived vector systems, such as, e.g., Moloney murine leukemia virus (MoMLV), are widely used and infect many different non-dividing cells. Lentiviruses can also infect many different cell types, including dividing and non-dividing cells and possess complex envelope proteins, which allows for highly specific cellular targeting. [0655] Retroviral vectors and specific protocols for how to use such vectors are disclosed In, e.g., U.S. Patent Nos. Manfred Gossen & Hermann Bujard, Tight control of gene expression in eukaryotic cells by tetracycline-responsive promoters, U.S. Patent No. 5,464,758 (Nov. 7, 1995) and Hermann Bujard & Manfred Gossen, Methods for regulating gene expression, U.S. Patent No. 5,814,618 (Sep. 29, 1998) David S. Hogness, Polynucleotides encoding insect steroid hormone receptor polypeptides and cells transformed with same, U.S. Patent No. 5,514,578 (May 7,1996) and David S. Hogness, Polynucleotide encoding insect ecdysone receptor, U.S. Patent 6,245,531 (Jun. 12, 2001); Elisabetta Vegeto et al., Progesterone receptor having C. terminal hormone binding domain truncations, U.S. Patent No. 5,364,791 (Nov. 15, 1994), Elisabetta Vegeto et al., Mutated steroid hormone receptors, methods for their use and molecular switch for gene therapy, U.S. Patent No. 5,874,534 (Feb. 23, 1999) and Elisabetta Vegeto et al., Mutated steroid hormone receptors, methods for their use and molecular switch for gene therapy, U.S. Patent No. 5,935,934 (Aug. 10, 1999). Furthermore, such viral delivery systems can be prepared by standard methods and are commercially available, see, e.g., BDTM Tet-Off and Tet-On Gene Expression Systems (BD Blosciences-Clonetech, Palo Alto, CA) and BDTM Tet-Off and Tet-On Gene Expression Systems User Manual, PT3001 -1, BD Biosciences Clonetech, (Mar. 14, 2003), GeneSwitchTM System (Invitrogen, Inc., Carlsbad, CA) and GeneSwitchTM System A Mifepristone-Regulated Expression System for Mammalian Cells version D, 25-0313, Invitrogen, Inc., (Nov. 4, 2002); ViraPowerTm Lentiviral Expression System (Invitrogen, Inc., Carlsbad, CA) and VIraPowerTM Lentiviral Expression System Instruction Manual 25-0501 version E, Invitrogen, Inc., (Dec. 8, 2003); and Complete Control" Retroviral Inducible Mammalian Expression System (Stratagene, La Jolla, CA) and Complete Control* Retroviral Inducible Mammalian Expression System Instruction Manual, 064005e. [0656] The methods disclosed in the present specification include, in part, expressing a modified Clostridial toxin from a polynucleotide molecule. it is envisioned that any of a variety of expression systems may be useful for expressing a modified Clostridial toxin from a polynucleotide molecule disclosed in the present specification, including, without limitation, cell-based systems and cell-free expression systems. Cell-based systems include, without limitation, viral expression systems, prokaryotic expression systems, yeast expression systems, baculoviral expression systems, insect expression systems and mammalian expression systems. Cell-free systems Include, without limitation, wheat germ extracts, rabbit reticulocyte extracts and E. coli extracts and generally are equivalent to the method 279 of 316 WO 2006/101809 PCT/US2006/008956 disclosed herein. Expression of a polynucleotide molecule using an expression system can include any of a variety of characteristics Including, without limitation, inducible expression, non-inducible expression, constitutive expression, viral-mediated expression, stably-integrated expression, and transient expression. Expression systems that include well-characterized vectors, reagents, conditions and cells are well-established and are readily available from commercial vendors that Include, without limitation, Ambion, Inc. Austin, TX; BD Biosciences-Clontech, Palo Alto, CA; BD Blosciences Pharmingen, San Diego, CA; Invitrogen, Inc, Carlsbad, CA; QIAGEN, Inc., Valencia, CA; Roche Applied Science, Indianapolis, IN; and Stratagene, La Jolla, CA. Non-limiting examples on the selection and use of appropriate heterologous expression systems are described in e.g., PROTEIN EXPRESSION. A PRACTICAL APPROACH (S. J. Higgins and B. David Hames eds., Oxford University Press, 1999); Joseph M. Fernandez & James P. Hoeffler, GENE EXPRESSION SYSTEMS. USING NATURE FOR THE ART OF ExPRESSION (Academic Press, 1999); and Meena Rai & Harish Padh, Expression Systems for Production of Heterologous Proteins, 80(9) CURRENT SCIENCE 1121-1128, (2001). These protocols are routine procedures well within the scope of one skilled in the art and from the teaching herein. [0657] A variety of cell-based expression procedures are useful for expressing a modified Clostridial toxin encoded by polynucleotide molecule disclosed in the present specification. Examples included, without limitation, viral expression systems, prokaryotic expression systems, yeast expression systems, baculoviral expression systems, insect expression systems and mammalian expression systems. Viral expression systems include, without limitation, the VlraPowerTM Lentiviral (Invitrogen, Inc., Carlsbad, CA), the Adenoviral Expression Systems (Invitrogen, Inc., Carlsbad, CA), the AdEasyTM XL Adenoviral Vector System (Stratagene, La Jolla, CA) and the ViraPort@ Retroviral Gene Expression System (Stratagene, La Jolla, CA). Non-limiting examples of prokaryotic expression systems include the Championm pET Expression System (EMD Blosciences-Novagen, Madison, WI), the TriExTM Bacterial Expression System (EMD Biosciences-Novagen, Madison, WI), the QlAexpress* Expression System (QIAGEN, Inc.), and the Affinity" Protein Expression and Purification System (Stratagene, La Jolla, CA). Yeast expression systems include, without limitation, the EasySeletTM Pichia Expression Kit (Invitrogen, Inc., Carlsbad, CA), the YES-EchoTm Expression Vector Kits (Invitrogen, Inc., Carlsbad, CA ) and the SpECTRATM S. pombe Expression System (Invitrogen, Inc., Carlsbad, CA). Non-limiting examples of baculoviral expression systems include the BaculoDirectTM (Invitrogen, Inc., Carlsbad, CA), the Bac-to-Bac* (Invitrogen, Inc., Carlsbad, CA), and the BD BaculoGodTM (BD Biosciences-Pharmigen, San Diego, CA). Insect expression systems include, without limitation, the Drosophila Expression System (DES*) (invitrogen, Inc., Carlsbad, CA), InsectSelectTm System (Invitrogen, Inc., Carlsbad, CA) and InsectDirectTM System (EMD Biosciences-Novagen, Madison, WI). Non-limiting examples of mammalian expression systems include the T-RExTM (Tetracycline-Regulated Expression) System (Invitrogen, Inc., Carlsbad, CA), the Fp-InTm T-RExTm System (Invitrogen, Inc., Carlsbad, CA), the pcDNATM System (Invitrogen, Inc., Carlsbad, CA), the pSecTag2 system (Invitrogen, Inc., Carlsbad, CA), the Exchanger* System, lnterPlayT' Mammalian TAP System (Stratagene, La Jolla, CA), Complete Control* Inducible 280 of 316 WO 2006/101809 PCT/US2006/008956 Mammalian Expression System (Stratagene, La Jolla, CA) and LacSwitch* 11 Inducible Mammalian Expression System (Stratagene, La Jolla, CA). [0658] Another procedure of expressing a modified Clostridial toxin encoded by polynucleotide molecule disclosed in the present specification employs a cell-free expression system such as, without limitation, prokaryotic extracts and eukaryotic extracts. Non-limiting examples of prokaryotic cell extracts include the RTS 100 E. coli HY Kit (Roche Applied Science, Indianapolis, IN), the ActivePro In Vitro Translation Kit (Ambion, Inc., Austin, TX), the EcoProTM System (EMD Biosciences-Novagen, Madison, WI) and the ExpresswayTm Plus Expression System (Invitrogen, Inc., Carlsbad, CA). Eukaryotic cell extract include, without limitation, the RTS 100 Wheat Germ CECF Kit (Roche Applied Science, Indianapolis, IN), the TnT* Coupled Wheat Germ Extract Systems (Promega Corp., Madison, WI), the Wheat Germ IVTTM Kit (Ambion, Inc., Austin, TX), the Retic Lysate IVTTh Kit (Ambion, Inc., Austin, TX), the PROTEINscript Il System (Ambion, Inc., Austin, TX) and the TnT* Coupled Reticulocyte Lysate Systems (Promega Corp., Madison, WI). EXAMPLES [0659] The following non-limiting examples are provided for illustrative purposes only in order to facilitate a more complete understanding of disclosed embodiments and are in no way intended to limit any of the embodiments disclosed in the present specification. Example 1 Construction of a modified Clostridial toxin comprising a modified Clostridial toxin binding domain with enhanced binding activity [0660] This example illustrates how to make a modified Clostridial toxin comprising a modified Clostridial toxin binding domain with enhanced binding activity using site-directed mutagenesis. [0661] A polynucleotide molecule encoding BoNT/A (SEQ ID NO: 1) is synthesized using standard procedures (BlueHeron* Biotechnology, Bothell, WA). Oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule is cloned using standard molecular biology methods into a pUCBHB1 vector at the Smal site to generate pUCBHB1/BoNT/A-ED-PAR1Tb. The synthesized polynucleotide molecule is verified by sequencing using Big Dye TerminatorTM Chemistry 3.1 (Applied Biosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Blosystems, Foster City, CA). [0662] If desired, an expression optimized polynucleotide molecule encoding BoNT/A (SEQ ID NO: 1) can be synthesized in order to improve expression in an Escherchia coi strain. The polynucleotide 281 of 316 WO 2006/101809 PCT/US2006/008956 molecule encoding the BoNT/A can be modified to 1) contain synonymous codons typically present in native polynucleotide molecules of an Escherchia coil strain; 2) contain a G+C content that more closely matches the average G+C content of native polynucleotide molecules found in an Escherichia coli strain; 3) reduce polymononucleotide regions found within the polynucleotide molecule; and/or 4) eliminate internal regulatory or structural sites found within the polynucleotide molecule, see, e.g., Lance E. Steward et aL Optimizing Expression of Active Botulinum Toxin Type E, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); Lance E. Steward et al. Optimizing Expression of Active Botulinum Toxin Type A, PCT Patent Serial No. 2005/027917 (Aug. 3, 2005). Once sequence optimization is complete, oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized Into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule Is cloned using standard molecular biology methods into a pUCBHB1 vector at the Smal site to generate pUCBHB1/BoNT/A. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminatorrm Chemistry 3.1 (Applied Blosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Biosystems, Foster City, CA). Is so desired, optimization to a different organism, such as, e.g., a yeast strain, an Insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); and Steward, supra, PCT Patent Serial No. 20051027917 (Aug. 3, 2005). [0663] A similar cloning strategy is used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding BoNT/B of SEQ ID NO: 2; a polynucleotide molecule encoding BoNT/C1 of SEQ ID NO: 3; a polynucleotide molecule encoding BoNT/D of SEQ ID NO: 4; a polynucleotide molecule encoding BoNT/E of SEQ ID NO: 5; a polynucleotide molecule encoding BoNT/F of SEQ ID NO: 6; a polynucleotide molecule encoding BoNT/G of SEQ ID NO: 7; and a polynucleotide molecule encoding TeNT of SEQ ID NO: 8. In addition, one skilled In the art can modify Clostridial toxins, such as, e.g., to Include an exogenous protease cleavage site within the di-chain loop region, or flexible spacer regions. [0664] To construct pET29/BoNT/A, a pUCBHB1/BoNT/A construct Is digested with restriction endonucleases that 1) excise the insert comprising the open reading frame of SEQ ID NO: 1 encoding BoNT/A; and 2) enable this insert to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, WI). This insert is subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A. The ligation mixture is transformed into chemically competent E. col DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and placed in a 37 "C Incubator for overnight growth. Bacteria containing expression constructs are identified as Kanamycin resistant colonies. Candidate constructs are isolated using an alkaline lysis plasmid mini preparation procedure and analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy yielded a pET29 expression construct 282 of 316 WO 2006/101809 PCTIUS2006/008956 comprising the polynucleotide molecule encoding the BoNT/A of SEQ ID NO: 1 operably-linked to a carboxyl terminal polyhistidine affinity binding peptide. [0665] A similar cloning strategy is used to make pET29 expression constructs comprising a polynucleotide molecule encoding BoNT/B of SEQ ID NO: 2; a polynucleotide molecule encoding BoNT/C1 of SEQ ID NO: 3; a polynucleotide molecule encoding BoNT/D of SEQ ID NO: 4; a polynucleotide molecule encoding BoNT/E of SEQ ID NO: 5; a polynucleotide molecule encoding BoNT/F of SEQ ID NO: 6; a polynucleotide molecule encoding BoNT/G of SEQ ID NO: 7; and a polynucleotide molecule encoding TeNT of SEQ ID NO: 8. [0666] To construct a modified BoNT/A comprising a modified binding domain with enhanced binding activity, specific amino acids Influencing binding activity will be changed. It is already known that amino acids Trp 1101, Gly 1102, Leu 1105, Tyr 1111, Tyr 1112, Gly 1158, lIe 1163, Asp 1179, Glu 1203, Phe 1252, Ser 1264, Trp 1266, Tyr 1267, Gin 1270, Gly 1279 and Trp 1282 of SEQ ID NO: 1 are important for function. To determine which amino acid substitutions could enhance the binding activity of a BoNT/A binding domain, computational protein design algorithims will generate novel proteins with optimized properties. The crystal structure of a BoNT/A binding domain will be used as the starting template for computational calculations. Potential amino acid candidates will be identified using a combined output from Protein Design Automation@ (PDA@) and Sequence Prediction AlgorithmTM (SPATM) calculations. For PDA calculations, the conformations of amino acids at variable positions will be represented as a set of backbone-independent side chain rotamers derived from the rotamer library. The energies of all possible combinations of the considered amino acids at the chosen variable positions will be calculated using a force field containing terms describing van der Waals, solvation, electrostatic, and hydrogen bond Interactions. The optimal (ground state) sequence will be determined using a Dead End Elimination (DEE) algorithm, and a Monte Carlo (MC) algorithm will be used to evaluate the energies of similar sequences around the predicted ground state. SPA calculations utilize a genetic algorithm to screen for low energy sequences, with energies being calculated during each round of "evolution" for those sequences being sampled. The conformations of amino acids will be represented as a set of side chain rotamers derived from a backbone-independent rotamer library using a flexible rotamer model. SPA calculations will generate sequences which will be subsequently clustered computationally into groups of similar sequences using a nearest neighbor single linkage hierarchical clustering algorithm. Critical contact amino acids will be fixed in both sequence and conformation and calculations will be carried out to evaluate single and combinatorial substitutions at variable amino acids. All amino acids in contact with these residues will be floated, that is the amino acid conformation but not the amino acid identity will be allowed to vary to allow for conformational adjustments. Final experimental substitutions will be chosen based on their predicted energies relative to the naturally occurring BoNT/A binding domain and their occupancy, that Is the number times the substitution occurred in the set of 1000 MC or genetic algorithm sequences. Two sets of design calculations will be carried out using Rosetta to identify substitutions predicted to stabilize the BoNT/A binding domain. In the first round, only single amino acid substitutions 283 of 316 WO 2006/101809 PCT/US2006/008956 will be modeled. In a second round, interface amino acids will be allowed to change to all 20 naturally occurring amino acids including the native amino acid type, but excluding cysteine, simultaneously. In each case, amino acid side chains contacting the substituted amino acid side chains will be repacked (allowing all rotamers of the native amino acid type). Sequences and conformations with low energies will be selected using a Monte-Carlo simulated annealing procedure. All resulting protein complex models will be rescored by computing a predicted binding energy. Final sequences were selected for the lowest binding energy [0667] Identified candidate amino acids will be changed using site-dIrected in vitro mutagenesis. A 50 pL reaction will be assembled using pET29/BoNT/A as a template, sense and antisense oligonucleotides encoding the desired amino acid change identified above, and reagents included with the QuickChange@ 11 XL Site-Directed Mutagenesis kit (Stratagene, La Jolla, CA). The polymerase chain reaction (PCR) mix will contain 5 pL of 1 ox Buffer, 1 pL of deoxyribonucleotides (dNTPs), 1pL of PfuUltra TM High Fidelity DNA polymerase (2.5 units/pL), 125 ng of each primer, 100 ng of template DNA, and nuclease-free water to a final volume of 50 pL The thermocycler conditions will be: one cycle of 95 0C for 60 seconds: 16 cycles of 95 *C for 30 seconds, 55 *C for 60 seconds, and 72 0C for 10 minutes; one cycle of 72 0C for 5 minutes; and 4 "C to hold. Following thermocycling, 1 pL of Dpnl restriction enzyme (Stratagene, La Jolla, CA) will be added to the reaction and will be incubated for 1 hour at 37 *C to digest the template DNA. The reaction will be purified by QIAquick kit (QIAGEN, Inc., Valencia, CA) and will be analysis by agarose gel electrophoresis to determine that the reaction produced full-length plasmid. The mutagenesis products will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 100 pg/mL of Ampicillin, and will be placed in a 37 *C incubator for overnight growth. Candidate mutagenesis constructs will be isolated as Ampicillin resistant colonies and will be analyzed using an alkaline lysis plasmid mini-preparation procedure to isolate the expression construct and restriction endonuclease digests to determine the presence of the insert. The incorporation of the point mutation will be determined by sequence analysis of candidate plasmid constructs. [0668] To test the binding activity of modified BoNT/A candidates with enhanced binding activity, the soluble portion of FGFR3 will be expressed recombinantly for use in surface plasmon resonance (SPR) binding assays, e.g., Biacore (Biacore Inc., Piscataway, NJ). The soluble portion of FGFR3 will be expressed as a fusion to streptavidin and the receptor will then be immobilized on an appropriate sensor chip. Utilizing a Biacore instrument, changes in local refractive Index as a result of receptor binding will be measured as a change in the SPR angle. The rates of change In the SPR angle will then be analyzed to determine association rate (K,,), dissociation rate (Kff) and the dissociation equilibrium constant (KD = Ko/ K,,). Modified BoNT/A candidates with enhanced binding activity will exhibit either an increased association rate, a decreased dissociation rate, both an increased association rate and a decreased dissociation rate, or a decreased dissociation equilibrium constant relative to the measurements obtained 284 of 316 WO 2006/101809 PCT/US2006/008956 from the naturally occurring BoNT/A from which the modifeid BoNT/A with enhanced binding activity was derived. Example 2 Construction of a modified Clostridial toxin comprising a non-toxin associated protein [0669] The following example illustrates how to make a modified Clostridial toxin comprising an enhanced targeting domain comprising a non-toxin associated protein. [0670] A polynucleotide molecule encoding BoNT/A-33/A is synthesized using standard procedures (BlueHeron* Biotechnology, Bothell, WA), as described in Example 1. BoNT/A-33/A is a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A a-trefoil domain, with amino acids 151 to 293 of SEQ ID NO: 9, a HA-33 p-trefoil domain from a Clostridial botulinum serotype A strain. If desired, an expression optimized polynucleotide molecule encoding BoNTIA-33/A can be synthesized in order to improve expression in to a different organism, such as, e.g., an Escher/chla col/ strain, a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); and Steward, supra, PCT Patent Serial No. 2005/027917 (Aug. 3, 2005).. The synthesized polynucleotide molecule is verified by sequencing using Big Dye TerminatorM Chemistry 3.1 (Applied Biosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Biosystems, Foster City, CA). [0671) A similar cloning strategy is used to make pUCBHB1 cloning constructs for BoNT/B-33/A, a modified BoNT/B where amino acids 1098-1291 of SEQ ID NO: 2 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; BoNT/C1-33/A, a modified BoNT/C1 where amino acids 1112-1291 of SEQ ID NO: 3 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; BoNT/D-33/A, a modified BoNT/D where amino acids 1099-1276 of SEQ ID NO: 4 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; BoNT/E-33/A, a modified BoNT/E where amino acids 1086-1252 of SEQ ID NO: 5 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; BoNT/F-33/A, a modified BoNT/F where amino acids 1106 1274 of SEQ ID NO: 6 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; BoNT/G-33/A, a modified BoNT/G where amino acids 1106-1297 of SEQ ID NO: 7 are replaced with amino acids 151 to 293 of SEQ ID NO: 9; and TeNT-33/A, a modified TeNT where amino acids 1128-1315 of SEQ ID NO: 8 are replaced with amino acids 151 to 293 of SEQ ID NO: 9. Similarly, the 0-trefoil domain from a Clostridial toxin indicated above can be replaced with a non-toxin associated protein s-trefoil domain comprising amino acids 10-144 of SEQ ID NO: 9; amino acids 10-144 of SEQ ID NO: 10; amino acids 10 144 of SEQ ID NO: 11; amino acids 10-146 of SEQ ID NO: 12; amino acids 10-144 of SEQ ID NO: 13; amino acids 10-144 of SEQ ID NO: 14; amino acids 10-146 of SEQ ID NO: 15; amino acids 10-141 of SEQ ID NO: 16; amino acids 10-141 of SEQ ID NO: 17; amino acids 10-141 of SEQ ID NO: 18; 151-293 of SEQ ID NO: 10; 151-293 of SEQ ID NO: 11; 153-294 of SEQ ID NO: 12; 151-279 of SEQ ID NO: 13; 285 of 316 WO 2006/101809 PCT/US2006/008956 151-292 of SEQ ID NO: 14; 153-291 of SEQ ID NO: 15; 148-285 of SEQ ID NO: 16; 148-286 of SEQ ID NO: 17; 148-286 of SEQ ID NO: 18; 9-146 of SEQ ID NO: 19; 9-146 of SEQ ID NO: 20; 9-146 of SEQ ID NO: 21; 9-146 of SEQ ID NO: 22; 1050-1194 of SEQ ID NO: 23; 1050-1199 of SEQ ID NO: 24; 1050 1194 of SEQ ID NO: 25; 1049-1198 of SEQ ID NO: 26; 1049-1197 of SEQ ID NO: 27; 1049-1197 of SEQ ID NO: 28; 1014-1163 of SEQ ID NO: 29; 1016-1160 of SEQ ID NO: 30; 1017-1166 of SEQ ID NO: 31; and 1050-1199 of SEQ ID NO: 32. [0672] To construct pET29/BoNT/A-33/A, a pUCBHB1/BoNT/A-33/A construct Is digested with restriction endonucleases that 1) excise the insert comprising the open reading frame encoding BoNT/A-33/A; and 2) enable this insert to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, WI). This Insert is subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-33/A. The ligation mixture is transformed into chemically competent E coil DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and placed in a 37 *C incubator for overnight growth. Bacteria containing expression constructs are identified as Kanamycin resistant colonies. Candidate constructs are isolated using an alkaline lysis plasmid mini-preparation procedure and analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy yielded a pET29 expression construct comprising the polynucleotide molecule encoding BoNT/A-33/A operably-linked to a carboxyl terminal polyhistidine affinity binding peptide. [0673] A similar cloning strategy is used to make pET29 expression constructs comprising a polynucleotide molecule encoding for BoNT/B-33/A, BoNT/C1-33/A, BoNT/D-33/A, BoNT/E-33/A, BoNT/F-33/A, BoNT/G-33/A, TeNT-33/A, as well as the modified Clostridial toxin indicated above comprising amino acids 10-144 of SEQ ID NO: 9; amino acids 10-144 of SEQ ID NO: 10; amino acids 10 144 of SEQ ID NO: 11; amino acids 10-146 of SEQ ID NO: 12; amino acids 10-144 of SEQ ID NO: 13; amino acids 10-144 of SEQ ID NO: 14; amino acids 10-146 of SEQ ID NO: 15; amino acids 10-141 of SEQ ID NO: 16; amino acids 10-141 of SEQ ID NO: 17; amino acids 10-141 of SEQ ID NO: 18; 151-293 of SEQ ID NO: 10; 151-293 of SEQ ID NO: 11; 153-294 of SEQ ID NO: 12; 151-279 of SEQ ID NO: 13; 151-292 of SEQ ID NO: 14; 153-291 of SEQ ID NO: 15; 148-285 of SEQ ID NO: 16; 148-286 of SEQ ID NO: 17; 148-286 of SEQ ID NO: 18; 9-146 of SEQ ID NO: 19; 9-146 of SEQ ID NO: 20; 9-146 of SEQ ID NO: 21; 9-146 of SEQ ID NO: 22; 1050-1194 of SEQ ID NO: 23; 1050-1199 of SEQ ID NO: 24; 1050 1194 of SEQ ID NO: 25; 1049-1198 of SEQ ID NO: 26; 1049-1197 of SEQ ID NO: 27; 1049-1197 of SEQ ID NO: 28; 1014-1163 of SEQ ID NO: 29; 1016-1160 of SEQ ID NO: 30; 1017-1166 of SEQ ID NO: 31; and 1050-1199 of SEQ ID NO: 32. Example 3 Construction of a modified Clostridial toxin comprising a non-toxin associated protein fold 286 of 316 WO 2006/101809 PCT/US2006/008956 [0674] The following example illustrates how to make a modified Ciostridial toxin comprising an enhanced targeting domain comprising a non-toxin associated protein fold. (0675] A polynucleotide molecule encoding BoNT/A-17y/A is synthesized using standard procedures (BlueHeron* Biotechnology, Bothell, WA), as described in Example 1. BoNT/A-17y/A is a BoNT/A modified to replace amino acids 1237-1296 of SEQ ID NO: 1, a y-fold from a BoNT/A 0-trefoil domain, with amino acids 95 to 146 of SEQ ID NO: 19, a y-fold from a HA-17 S-trefoil domain from a Clostridial botulinum serotype A strain. If desired, an expression optimized polynucleotide molecule encoding BoNT/A-1 7y/A can be synthesized in order to improve expression in to a different organism, such as, e.g., an Escherichia coli strain, a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); and Steward, supra, PCT Patent Serial No. 2005/027917 (Aug. 3, 2005).. The synthesized polynucleotide molecule is verified by sequencing using Big Dye TerminatorTM Chemistry 3.1 (Applied Blosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Biosystems, Foster City, CA). [0676] A similar cloning strategy is used to make pUCBHB1 cloning constructs for BoNTIB-17y/A, a modified BoNT/B where amino acids 1223-1291 of SEQ ID NO: 2 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; BoNT/C1-F18y, a modified BoNT/Cl where amino acids 1230-1291 of SEQ ID NO: 3 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; BoNT/D-17y/A, a modified BoNTID where amino acids 1219-1276 of SEQ ID NO: 4 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; BoNT/E-17y/A, a modified BoNT/E where amino acids 1199-1252 of SEQ ID NO: 5 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; BoNT/F-17y/A, a modified BoNT/F where amino acids 1222 1274 of SEQ ID NO: 6 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; BoNT/G-17y/A, a modified BoNT/G where amino acids 1231-1297 of SEQ ID NO: 7 are replaced with amino acids 95 to 146 of SEQ ID NO: 19; and TeNT-17y/A, a modified TeNT where amino acids 1255-1315 of SEQ ID NO: 8 are replaced with amino acids 95 to 146 of SEQ ID NO: 19. [0677] Similarly, the y-fold from a HA-17/A 0-trefoil domain can replace amino acids 1111-1162 of SEQ ID NO: 1, an a-fold from a BoNT/A P-trefoil domain; amino acids 1098-1147 of SEQ ID NO: 2, an a-fold from a BoNT/B 0-trefoil domain; amino acids 1112-1150 of SEQ ID NO: 3, an a-fold from a BoNT/C1 p trefoil domain; amino acids 1099-1137 of SEQ ID NO: 4, an a-fold from a BoNT/D 1-trefoil domain; amino acids 1086-1129 of SEQ ID NO: 5, an a-fold from a BoNT/E p-trefoil domain; amino acids 1106-1152 of SEQ ID NO: 6, an a-fold from a BoNT/F p-trefoil domain; amino acids 1106-1153 of SEQ ID NO: 7, an a fold from a BoNT/G p-trefoil domain; or amino acids 1128-1177 of SEQ ID NO: 8, an a-fold from a TeNT 1-trefoil domain. Similarly, the y-fold from a HA-17/A P-trefoil domain can replace amino acids 1179-1223 of SEQ ID NO: 1, a 1-fold from a BoNT/A 0-trefoil domain; amino acids 1166-1210 of SEQ ID NO: 2, a 1 fold from a BoNT/B P-trefoil domain; amino acids 1167-1218 of SEQ ID NO: 3, a 0-fold from a BoNT/C1 P-trefoil domain; amino acids 1154-1207 of SEQ ID NO: 4, a 0-fold from a BoNT/D P-trefoil domain; 287 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 1147-1190 of SEQ ID NO: 5, a 0-fold from a BoNT/E P-trefoil domain; amino acids 1172 1213 of SEQ ID NO: 6, a -fold from a BoNT/F 0-trefoil domain; amino acids 1173-1218 of SEQ ID NO: 7, a 0-fold from a BoNT/G -trefoil domain; or amino acids 1195-1240 of SEQ ID NO: 8, a 0-fold from a TeNT (-trefoil domain. [0678] Similarly, an a-fold, 0-fold or y-fold from a 0-trefoil domain from a Clostridial toxin indicated above can be replaced with a HA-17 y-fold comprising amino acids 95-146 of SEQ ID NO: 20, amino acids 95 146 of SEQ ID NO: 21, or amino acids 95-146 of SEQ ID NO: 22; a HA-33 y-fold comprising amino acids 105-144 of SEQ ID NO: 9, amino acids 105-144 of SEQ ID NO: 10, amino acids 105-144 of SEQ ID NO: 11, amino acids 107-146 of SEQ ID NO: 12, amino acids 105-144 of SEQ ID NO: 13, amino acids 105 144 of SEQ ID NO: 14, amino acids 107-146 of SEQ ID NO: 15, amino acids 103-141 of SEQ ID NO: 16, amino acids 103-141 of SEQ ID NO: 17, amino acids 103-141 of SEQ ID NO: 18, amino acids 249-293 of SEQ ID NO: 9, amino acids 249-293 of SEQ ID NO: 10, amino acids 249-293 of SEQ ID NO: 11, amino acids 250-294 of SEQ ID NO: 12, amino acids 249-279 of SEQ ID NO: 13, amino acids 248-292 of SEQ ID NO: 14, amino acids 249-291 of SEQ ID NO: 15, amino acids 241-285 of SEQ ID NO: 16, amino acids 242-286 of SEQ ID NO: 17, or amino acids 242-286 of SEQ ID NO: 18; or a NTNH y-fold comprising amino acids 1149-1194 of SEQ ID NO: 23, amino acids 1149-1199 of SEQ ID NO: 24, amino acids 1149 1194 of SEQ ID NO: 25, amino acids 1148-1198 of SEQ ID NO: 26, amino acids 1148-1197 of SEQ ID NO: 27, amino acids 1148-1197 of SEQ ID NO: 28, amino acids 1114-1163 of SEQ ID NO: 29, amino acids 1115-1160 of SEQ ID NO: 30, amino acids 1117-1166 of SEQ ID NO: 31, or amino acids 1150 1199 of SEQ ID NO: 32. [0679] Likewise, an a-fold, 0-fold or y-fold from a P-trefoil domain from a Clostridial toxin indicated above can be replaced with a HA-17 a-fold comprising amino acids 9-50 of SEQ ID NO: 19, amino acids 9-50 of SEQ ID NO: 20, amino acids 9-50 of SEQ ID NO: 21, or amino acids 9-50 of SEQ ID NO: 22; a HA-33 a fold comprising amino acids 10-54 of SEQ ID NO: 9, amino acids 10-54 of SEQ ID NO: 10, amino acids 10-54 of SEQ ID NO: 11, amino acids 10-56 of SEQ ID NO: 12, amino acids 10-54 of SEQ ID NO: 13, amino acids 10-54 of SEQ ID NO: 14, amino acids 10-56 of SEQ ID NO: 15, amino acids 10-54 of SEQ ID NO: 16, amino acids 10-54 of SEQ ID NO: 17, amino acids 10-54 of SEQ ID NO: 18, amino acids 151 195 of SEQ ID NO: 9, amino acids 151-195 of SEQ ID NO: 10, amino acids 151-195 of SEQ ID NO: 11, amino acids 153-197 of SEQ ID NO: 12, amino acids 151-195 of SEQ ID NO: 13, amino acids 151-195 of SEQ ID NO: 14, amino acids 153-197 of SEQ ID NO: 15, amino acids 148-190 of SEQ ID NO: 16, amino acids 148-190 of SEQ ID NO: 17, or amino acids 148-190 of SEQ ID NO: 18; or a NTNH a-fold comprising amino acids 1050-1097 of SEQ ID NO: 23, amino acids 1050-1097 of SEQ ID NO: 24, amino acids 1050-1097 of SEQ ID NO: 25, amino acids 1049-1096 of SEQ ID NO: 26, amino acids 1049-1096 of SEQ ID NO: 27, amino acids 1049-1096 of SEQ ID NO: 28, amino acids 1014-1061 of SEQ ID NO: 29, amino acids 1016-1063 of SEQ ID NO: 30, amino acids 1017-1064 of SEQ ID NO: 31, or amino acids 1050-1097 of SEQ ID NO: 32. 288 of 316 WO 2006/101809 PCT/US2006/008956 [0680] Further, an a-fold, a-fold or y-fold from a P-trefoil domain from a Clostridial toxin indicated above can be replaced with a HA-17 0-fold comprising amino acids 55-91 of SEQ ID NO: 19, amino acids 55-91 of SEQ ID NO: 20, amino acids 55-91 of SEQ ID NO: 21, or amino acids 55-91 of SEQ ID NO: 22; a HA 33 P-fold comprising amino acids 60-100 of SEQ ID NO: 9, amino acids 60-100 of SEQ ID NO: 10, amino acids 60-100 of SEQ ID NO: 11, amino acids 62-102 of SEQ ID NO: 12, amino acids 60-100 of SEQ ID NO: 13, amino acids 60-100 of SEQ ID NO: 14, amino acids 62-102 of SEQ ID NO: 15, amino acids 60 98 of SEQ ID NO: 16, amino acids 60-98 of SEQ ID NO: 17, amino acids 60-98 of SEQ ID NO: 18, amino acids 200-242 of SEQ ID NO: 9, amino acids 200-242 of SEQ ID NO: 10, amino acids 200-242 of SEQ ID NO: 11, amino acids 202-243 of SEQ ID NO: 12, amino acids 200-242 of SEQ ID NO: 13, amino acids 200-241 of SEQ ID NO: 14, amino acids 200-242 of SEQ ID NO: 15, amino acids 195-234 of SEQ ID NO: 16, amino acids 195-235 of SEQ ID NO: 17, or amino acids 195-235 of SEQ ID NO: 18; or a NTNH s-fold comprising amino acids 1111-1138 of SEQ ID NO: 23, amino acids 1111-1139 of SEQ ID NO: 24, amino acids 1111-1138 of SEQ ID NO: 25, amino acids 1110-1138 of SEQ ID NO: 26, amino acids 1110-1138 of SEQ ID NO: 27, amino acids 1110-1138 of SEQ ID NO: 28, amino acids 1075-1103 of SEQ ID NO: 29, amino acids 1077-1104 of SEQ ID NO: 30, amino acids 1078-1106 of SEQ ID NO: 31, or amino acids 1111-1139 of SEQ ID NO: 32. [06811 To construct pET29/BoNT/A-17y/A, a pUCBHB1/BoNT/A-17y/A construct is digested with restriction endonucleases that 1) excise the insert comprising the open reading frame encoding BoNT/A 17y/A; and 2) enable this insert to be operably-linked to a pET29 vector (EMD Blosciences-Novagen, Madison, WI). This Insert is subcloned using a T4 DNA ligase procedure into a pET29 vector that Is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-17y/A. The ligation mixture is transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and placed in a 37 *C incubator for overnight growth. Bacteria containing expression constructs are identified as Kanamycin resistant colonies. Candidate constructs are isolated using an alkaline lysis plasmid mini preparation procedure and analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy yielded a pET29 expression construct comprising the polynucleotide molecule encoding BoNT/A-17y/A operably-linked to a carboxyl terminal polyhistidine affinity binding peptide. [0682] A similar cloning strategy Is used to make pET29 expression constructs comprising a polynucleotide molecule encoding BoNT/B-17y/A, BoNT/C1-17y/A, BoNT/D-17y/A, BoNT/E-17y/A, BoNT/F-17y/A, BoNT/G-17y/A, TeNT-17y/A, BoNT/A-33-1y/A, BoNTIB-33-1y/A, BoNT/C1-33-1y/A, BoNT/D-33-1y/A, BoNT/E-33-1y/A, BoNT/F-33-1y/A, BoNT/G-33-1y/A, TeNT-33-1y/A, BoNT/A-33-2y/A, BoNT/B-33-2y/A, BoNT/C1-33-2y/A, BoNT/D-33-2y/A, BoNT/E-33-2y/A, BoNT/F-33-2y/A, BoNT/G-33 2y/A, TeNT-33-2y/A, BoNTIB-NTNHy/A, BoNT/B-NTNHy/A, BoNT/C1-NTNHy/A, BoNT/D-NTNHy/A, BoNT/E-NTNHy/A, BoNT/F-NTNHy/A, BoNT/G-NTNHy/A, TeNT-NTNHy/A, BoNT/A-17a/A, BoNT/B 17a/A, BoNT/C1-17a/A, BoNT/D-17a/A, BoNTIE-17a/A, BoNT/F-17a/A, BoNT/G-17a/A, TeNT-17a/A, 289 of 316 WO 2006/101809 PCT/US2006/008956 BoNT/A-33-la/A, BoNT/B-33-la/A, BoNT/C1-33-1a/A, BoNT/D-33-la/A, BoNT/E-33-la/A, BoNT/F-33 1a/A, BoNT/G-33-la/A, TeNT-33-la/A, BoNT/A-33-2a/A, BoNT/B-33-2a/A, BoNT/Cl-33-2a/A, BoNT/D 33-2a/A, BoNT/E-33-2a/A, BoNT/F-33-2a/A, BoNT/G-33-2a/A, TeNT-33-2a/A, BoNT/B-NTNHa/A, BoNT/B-NTNHa/A, BoNT/C1-NTNHa/A, BoNT/D-NTNHa/A, BoNT/E-NTNHa/A, BoNT/F-NTNHa/A, BoNT/G-NTNHa/A, TeNT-NTNHa, BoNT/A-170/A, BoNT/B-17P/A, BoNT/C1-170/A, BoNT/D-170/A, BoNT/E-17f/A, BoNTJF-170/A, BoNT/G-17R/A, TeNT-170/A, BoNT/A-33-11/A, BoNT/B-33-113/A, BoNT/C1-33-10/A, BoNT/D-33-10/A, BoNT/E-33-10/A, BoNT/F-33-1 /A, BoNT/G-33-1o/A, TeNT-33 110/A, BoNT/A-33-20/A, BoNT/B-33-20/A, BoNT/C1-33-20/A, BoNT/D-33-20/A, BoNT/E-33-20/A, BoNT/F 33-2/A, BoNT/G-33-20/A, TeNT-33-20/A, BoNTIB-NTNHS/A, BoNT/B-NTNHs/A, BoNT/C1-NTNHP/A, BoNT/D-NTNHf/A, BoNT/E-NTNHP/A, BoNT/F-NTNHO/A, BoNT/G-NTNHS/A, TeNT-NTNHP, [0683] A similar cloning strategy Is also used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin Indicated above that has its a-fold or 1-fold replaced by amino acids comprising a HA-17 a-fold, 0-fold or y-fold; amino acids comprising a HA-33 la fold, 13-fold, ly-fold, 2a-fold, 2p-old, or 2y-fold; or amino acids comprising a NTNH a-fold, p-fold or y fold. Example 4 Construction of a modified Clostridial toxin comprising a FGF that selectively binds to a FGFR3 [0684] The following example illustrates how to make a modified Clostridial toxin comprising an enhanced targeting domain comprising a FGF that selectively binds to a FGFR3. [0685] A polynucleotide molecule encoding BoNT/A-F18 is synthesized using standard procedures (BlueHeron* Biotechnology, Bothell, WA), as described in Example 1. BoNT/A-F18 is a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A 0-trefoil domain, with amino acids 54 to 183 of SEQ ID NO: 39, a FGF-18 0-trefoil domain. If desired, an expression optimized polynucleotide molecule encoding BoNT/A-F18 can be synthesized in order to Improve expression in to a different organism, such as, e.g., an Escher/ch/a coli strain, a yeast strain, an Insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); and Steward, supra, PCT Patent Serial No. 2005/027917 (Aug. 3, 2005).. The synthesized polynucleotide molecule is verified by sequencing using Big Dye TerminatorTM Chemistry 3.1 (Applied Biosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Biosystems, Foster City, CA). [0686] A similar cloning strategy is used to make pUCBHB1 cloning constructs for BoNT/B-F18, a modified BoNT/B where amino acids 1098-1291 of SEQ ID NO: 2 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; BoNT/C1-F18, a modified BoNT/C1 where amino acids 1112-1291 of SEQ ID NO: 3 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; BoNTID-F18, a modified BoNT/D where 290 of 316 WO 2006/101809 PCT/US2006/008956 amino acids 1099-1276 of SEQ ID NO: 4 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; BoNT/E-F18, a modified BoNT/E where amino acids 1086-1252 of SEQ ID NO: 5 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; BoNT/F-F18, a modified BoNT/F where amino acids 1106-1274 of SEQ ID NO: 6 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; BoNT/G-F18, a modified BoNT/G where amino acids 1106-1297 of SEQ ID NO: 7 are replaced with amino acids 54 to 183 of SEQ ID NO: 39; and TeNT-F1 8, a modified TeNT where amino acids 1128-1315 of SEQ ID NO: 8 are replaced with amino acids 54 to 183 of SEQ ID NO: 39. Similarly, the P-trefoil domain from a Clostridial toxin indicated above can be replaced with a FGF p-trefoil domain comprising amino acids 26-155 of SEQ ID NO: 33; amino acids 29-155 of SEQ ID NO: 34; amino acids 83-206 of SEQ ID NO: 35; amino acids 43 172 of SEQ ID NO: 36; amino acids 63-196 of SEQ ID NO: 37; amino acids 55-183 of SEQ ID NO: 38; and amino acids 54-183 of SEQ ID NO: 39. [0687] To construct pET29/BoNT/A-F18, a pUCBHB1/BoNT/A-F18 construct is digested with restriction endonucleases that 1) excise the insert comprising the open reading frame encoding BoNT/A-F1 8; and 2) enable this insert to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, WI). This insert is subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-F18. The ligation mixture is transformed into chemically competent E. col DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and placed in a 37 "C incubator for overnight growth. Bacteria containing expression constructs are identified as Kanamycin resistant colonies. Candidate constructs are isolated using an alkaline lysis plasmid mini-preparation procedure and analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy yielded a pET29 expression construct comprising the polynucleotide molecule encoding BoNT/A-F18 operably-linked to a carboxyl terminal polyhistidine affinity binding peptide. [0688] A similar cloning strategy is used to make pET29 expression constructs comprising a polynucleotide molecule encoding for BoNT/B-F18, BoNT/C1-F18, BoNT/D-F18, BoNT/E-F18, BoNT/F F18, BoNT/G-F18, TeNT-F18, as well as the modified Clostridial toxin indicated above comprising amino acids 26-155 of SEQ ID NO: 33; amino acids 29-155 of SEQ ID NO: 34; amino acids 83-206 of SEQ ID NO: 35; amino acids 43-172 of SEQ ID NO: 36; amino acids 63-196 of SEQ ID NO: 37; amino acids 55 183 of SEQ ID NO: 38; and amino acids 54-183 of SEQ ID NO: 39. Example 5 Construction of a modified Clostridial toxin comprising a FGF fold that selectively binds to a FGFR3 [0689] The following example illustrates how to make a modified Clostridial toxin comprising an enhanced targeting domain comprising a FGF fold that selectively binds to a FGFR3. 291 of 316 WO 2006/101809 PCT/US2006/008956 [0690] A polynucleotide molecule encoding BoNT/A-F1 By Is synthesized using standard procedures (BlueHeron* Biotechnology, Bothell, WA), as described in Example 1. BoNT/A-F18y is a BoNT/A modified to replace amino acids 1237-1296 of SEQ ID NO: 1, a y-fold from a BoNT/A p-trefoil domain, with amino acids 138 to 183 of SEQ ID NO: 39, a y-fold from a FGF-18 p-trefoil domain. If desired, an expression optimized polynucleotide molecule encoding BoNT/A-F18y can be synthesized in order to improve expression in to a different organism, such as, e.g., an Escherichia coli strain, a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, PCT Patent Serial No. 2005/020578 (Jun. 9, 2005); and Steward, supra, PCT Patent Serial No. 2005/027917 (Aug. 3, 2005).. The synthesized polynucleotide molecule is verified by sequencing using Big Dye TerminatorTM Chemistry 3.1 (Applied Biosystems, Foster City, CA) and an ABI 3100 sequencer (Applied Biosystems, Foster City, CA). (0691] A similar cloning strategy is used to make pUCBHB1 cloning constructs for BoNT/B-F18y, a modified BoNT/B where amino acids 1223-1291 of SEQ ID NO: 2 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; BoNT/C1-F18y, a modified BoNT/C1'where amino acids 1230-1291 of SEQ ID NO: 3 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; BoNT/D-F18y, a modified BoNT/D where amino acids 1219-1276 of SEQ ID NO: 4 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; BoNT/E-F1 By, a modified BoNT/E where amino acids 1199-1252 of SEQ ID NO: 5 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; BoNT/F-F18y, a modified BoNT/F where amino acids 1222 1274 of SEQ ID NO: 6 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; BoNT/G-F18y, a modified BoNT/G where amino acids 1231-1297 of SEQ ID NO: 7 are replaced with amino acids 138 to 183 of SEQ ID NO: 39; and TeNT-F18y, a modified TeNT where amino acids 1255-1315 of SEQ ID NO: 8 are replaced with amino acids 138 to 183 of SEQ ID NO: 39. Similarly, the y-fold from a FGF-18 -trefoil domain can replace amino acids 1111-1162 of SEQ ID NO: 1, an a-fold from a BoNT/A p-trefoil domain; amino acids 1098-1147 of SEQ ID NO: 2, an a-fold from a BoNT/B 5-trefoil domain; amino acids 1112 1150 of SEQ ID NO: 3, an a-fold from a BoNT/C1 1-trefoil domain; amino acids 1099-1137 of SEQ ID NO: 4, an a-fold from a BoNT/D 1-trefoil domain; amino acids 1086-1129 of SEQ ID NO: 5, an a-fold from a BoNT/E p-trefoil domain; amino acids 1106-1152 of SEQ ID NO: 6, an a-fold from a BoNT/F 0-trefoil domain; amino acids 1106-1153 of SEQ ID NO: 7, an a-fold from a BoNT/G P-trefoil domain; or amino acids 1128-1177 of SEQ ID NO: 8, an a-fold from a TeNT -trefoil domain. Similarly, the y-fold from a FGF-18 0-trefoil domain can replace amino acids 1179-1223 of SEQ ID NO: 1, a P-fold from a BoNT/A p trefoil domain; amino acids 1166-1210 of SEQ ID NO: 2, a P-fold from a BoNT/B 0-trefoil domain; amino acids 1167-1218 of SEQ ID NO: 3, a p-fold from a BoNT/C1 1-trefoil domain; amino acids 1154-1207 of SEQ ID NO: 4, a P-fold from a BoNT/D p-trefoil domain; amino acids 1147-1190 of SEQ ID NO: 5, a p fold from a BoNT/E P-trefoil domain; amino acids 1172-1213 of SEQ ID NO: 6, a 1-fold from a BoNT/F p trefoil domain; amino acids 1173-1218 of SEQ ID NO: 7, a 1-fold from a BoNT/G P-trefoil domain; or amino acids 1195-1240 of SEQ ID NO: 8, a 0-fold from a TeNT P-trefoil domain. 292 of 316 WO 2006/101809 PCT/US2006/008956 [0692] Similarly, an a-fold, -fold or y-fold from a s-trefoil domain from a Clostridial toxin indicated above can be replaced with a FGF y-fold comprising amino acids 109-155 of SEQ ID NO: 33; amino acids 115 155 of SEQ ID NO: 34; amino acids 166-206 of SEQ ID NO: 35; amino acids 127-172 of SEQ ID NO: 36; amino acids 148-196 of SEQ ID NO: 37; or amino acids 138-183 of SEQ ID NO: 38. Likewise, an a-fold, P-fold or y-fold from a S-trefoil domain from a Clostridial toxin Indicated above can be replaced with a FGF a-fold comprising amino acids 26-64 of SEQ ID NO: 33; amino acids 29-67 of SEQ ID NO: 34; amino acids 83-121 of SEQ ID NO: 35; amino acids 43-80 of SEQ ID NO: 36; amino acids 63-100 of SEQ ID NO: 37; amino acids 55-91 of SEQ ID NO: 38; or amino acids 54-91 of SEQ ID NO: 39. Further, an a fold, 0-fold or y-fold from a 0-trefoil domain from a Clostridial toxin indicated above can be replaced with a FGF -fold comprising amino acids 68-105 of SEQ ID NO: 33; amino acids 71-111 of SEQ ID NO: 34; amino acids 125-162 of SEQ ID NO: 35; amino acids 84-123 of SEQ ID NO: 36; amino acids 104-144 of SEQ ID NO: 37; amino acids 95-134 of SEQ ID NO: 38; or amino acids 95-134 of SEQ ID NO: 39. [0693] To construct pET29/BoNT/A-F18, a pUCBHB1/BoNT/A-F18y construct is digested with restriction endonucleases that 1) excise the insert comprising the open reading frame encoding BoNT/A-F1 8y; and 2) enable this insert to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, WI). This insert is subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-F18y. The ligation mixture is transformed Into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, CA) using a heat shock method, plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and placed in a 37 *C incubator for ovemight growth. Bacteria containing expression constructs are identified as Kanamycin resistant colonies. Candidate constructs are isolated using an alkaline lysis plasmid mini-preparation procedure and analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the Insert. This cloning strategy yielded a pET29 expression construct comprising the polynucleotide molecule encoding BoNT/A-F18y operably-linked to a carboxyl terminal polyhistidine affinity binding peptide. [0694] A similar cloning strategy is used to make pET29 expression constructs comprising a polynucleotide molecule encoding for BoNT/B-F18y, BoNT/C1-F18y, BoNT/D-F18y, BoNT/E-F18y, BoNT/F-F18y, BoNT/G-F18y, TeNT-F18y, BoNT/A-F18a, BoNT/B-F18a, BoNT/C1-F18a, BoNT/D-F18a, BoNT/E-F1 8a, BoNT/F-F1 Ba, BoNT/G-F1 8a, TeNT-F1 8a, BoNT/A-F1 8, BoNT/B-F1 8, BoNT/C1 -F180, BoNT/D-F18@, BoNT/E-F18, BoNT/F-F18p, BoNT/G-F18P, or TeNT-F18P, as well as the modified Clostridial toxin indicated above comprising amino acids 109-155 of SEQ ID NO: 33; amino acids 115 155 of SEQ ID NO: 34; amino acids 166-206 of SEQ ID NO: 35; amino acids 127-172 of SEQ ID NO: 36; amino acids 148-196 of SEQ ID NO: 37; amino acids 138-183 of SEQ ID NO: 38; amino acids 26-64 of SEQ ID NO: 33; amino acids 29-67 of SEQ ID NO: 34; amino acids 83-121 of SEQ ID NO: 35; amino acids 43-80 of SEQ ID NO: 36; amino acids 63-100 of SEQ ID NO: 37; amino acids 55-91 of SEQ ID NO: 38; amino acids 54-91 of SEQ ID NO: 39; amino acids 68-105 of SEQ ID NO: 33; amino acids 71-111 of SEQ ID NO: 34; amino acids 125-162 of SEQ ID NO: 35; amino acids 84-123 of SEQ ID NO: 36; amino 293 of 316 WO 2006/101809 PCT/US2006/008956 acids 104-144 of SEQ ID NO: 37; amino acids 95-134 of SEQ ID NO: 38; or amino acids 95-134 of SEQ ID NO: 39. Example 6 Expression of Modified Clostridial Toxins In a Bacterial Cell [0695] The following example illustrates a procedure useful for expressing any of the modified Clostridial toxins disclosed in the present specification in a bacterial cell. (0696] An expression construct, such as, e.g., any of the expression constructs in Examples 1-5, is introduced into chemically competent E. coil BL21 (DE3) cells (Invitrogen, Inc, Carlsbad, CA) using a heat-shock transformation protocol. The heat-shock reaction is plated onto 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin and is placed in a 37 *C incubator for ovemight growth. Kanamycin-resistant colonies of transformed E. cofi containing the expression construct are used to inoculate a baffled flask containing 3.0 mL of PA-0.5G media containing 50 pg/mL of Kanamycin which is then placed in a 37 *C incubator, shaking at 250 rpm, for overnight growth. The resulting overnight starter culture is in turn used to inoculate a 3 L baffled flask containing ZYP-5052 autoinducing media containing 50 ig/mL of Kanamycin at a dilution of 1:1000. Culture volumes ranged from about 600 mL (20% flask volume) to about 750 mL (25% flask volume). These cultures are grown in a 37 *C incubator shaking at 250 rpm for approximately 5.5 hours and are then transferred to a 16 *C incubator shaking at 250 rpm for overnight expression. Cells are harvested by centrifugation (4,000 rpm at 4 *C for 20-30 minutes) and are used immediately, or stored dry at -80 *C until needed. Example 7 Purification and Quantification of Modified Clostridial Toxins [0697] The following example illustrates methods useful for purification and quantification of any modified Clostridial toxins disclosed in the present specification. [0698] For immobilized metal affinity chromatography (IMAC) protein purification, E. co/i BL21 (DE3) cell pellets used to express a modified Clostridial toxin, as described in Example 7, are resuspended in Column Binding Buffer (25 mM N-(2-hydroxyethyl) piperazine-N-(2-ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 10 mM imidazole; 2x Protease Inhibitor Cocktail Set Ill (EMD Biosciences Calblochem, San Diego CA); 5 units/mL of Benzonase (EMD Biosciences-Novagen, Madison, WI); 0.1% (v/v) Triton-X* 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol), and then are transferred to a cold Oakridge centrifuge tube. The cell suspension is sonicated on ice (10-12 pulses of 10 seconds at 40% amplitude with 60 seconds cooling intervals on a Branson Digital Sonifier) in order to lyse the cells and then is centrifuged (16,000 rpm at 4 *C for 20 minutes) to clarify the lysate. An immobilized metal affinity 294 of 316 WO 2006/101809 PCT/US2006/008956 chromatography column is prepared using a 20 mL Econo-Pac column support (Blo-Rad Laboratories, Hercules, CA) packed with 2.5-5.0 mL of TALONTM SuperFlow Co2 affinity resin (BD Biosciences Clontech, Palo Alto, CA), which is then equilibrated by rinsing with 5 column volumes of demonized, distilled water, followed by 5 column volumes of Column Binding Buffer. The clarified lysate is applied slowly to the equilibrated column by gravity flow (approximately 0.25-0.3 mUminute). The column is then washed with 5 column volumes of Column Wash Buffer (N-(2-hydroxyethyl) piperazine-N'-(2 ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 10 mM imidazole; 0.1% (v/v) Triton-X* 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol). The modified Clostridial toxin is eluted with 20-30 mL of Column Elution Buffer (25 mM N-(2-hydroxyethyl) piperazine-N'-(2-ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 500 mM imidazole; 0.1% (v/v) Triton-X* 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol) and is collected In approximately twelve 1 mL fractions. The amount of modified Clostridial toxin contained in each elution fraction is determined by a Bradford dye assay. in this procedure, 20 pL aliquots of each 1.0 mL fraction is combined with 200 pL of Bio-Rad Protein Reagent (Bio-Rad Laboratories, Hercules, CA), diluted 1 to 4 with deionized, distilled water, and then the Intensity of the colorimetric signal is measured using a spectrophotometer. The five fractions with the strongest signal are considered the elution peak and are combined together. Total protein yield is determined by estimating the total protein concentration of the pooled peak elution fractions using bovine gamma globulin as a standard (Bio-Rad Laboratories, Hercules, CA). [0699] For purification of a modified Clostridial toxin using a FPLC desalting column, a HiPrepTm 26/10 size exclusion column (Amersham Blosciences, Piscataway, NJ) is pre-equilibrated with 80 mL of 4 0C Column Buffer (50 mM sodium phosphate, pH 6.5). After the column is equilibrated, a modified Clostridial toxin sample is applied to the size exclusion column with an isocratic mobile phase of 4 *C Column Buffer and at a flow rate of 10 mUminute using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, CA). The desalted modified Clostridial toxin sample is collected as a single fraction of approximately 7-12 mL. [0700] For purification of a modified Clostridial toxin using a FPLC ion exchange column, a modified Clostridial toxin sample that has been desalted following elution from an IMAC column is applied to a 1 mL 01Tm anion exchange column (Blo-Rad Laboratories, Hercules, CA) using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, CA). The sample is applied to the column in 4 *C Column Buffer (50 mM sodium phosphate, pH 6.5) and is eluted by linear gradient with 4 "C Elution Buffer (50 mM sodium phosphate, 1 M sodium chloride, pH 6.5) as follows: step 1, 5.0 mL of 5% Elution Buffer at a flow rate of 1 mUminute; step 2, 20.0 mL of 5-30% Elution Buffer at a flow rate of 1 mUminute; step 3, 2.0 mL of 50% Elution Buffer at a flow rate of 1.0 mUminute; step 4, 4.0 mL of 100% Elutlon Buffer at a flow rate of 1.0 mUminute; and step 5, 5.0 mL of 0% Elution Buffer at a flow rate of 1.0 mUminute. Elution of modified Clostridial toxin from the column is monitored at 280, 260, and 214 nm, and peaks absorbing above a minimum threshold (0.01 au) at 280 nm are collected. Most of the modified 295 of 316 WO 2006/101809 PCT/US2006/008956 Clostridial toxin will elute at a sodium chloride concentration of approximately 100 to 200 mM. Average total yields of modified Clostridial toxin will be determined by a Bradford assay. (0701] Expression of a modified Clostridial toxin is analyzed by polyacrylamide gel electrophoresis. Samples purified using the procedure described above are added to 2x LDS Sample Buffer (Invitrogen, Inc, Carlsbad, CA) and are separated by MOPS polyacrylamide gel electrophoresis using NuPAGE Novex 4-12% Bis-Tris precast polyacrylamide gels (Invitrogen, Inc, Carlsbad, CA) under denaturing, reducing conditions. Gels are stained with SYPRO* Ruby (Bio-Rad Laboratories, Hercules, CA) and the separated polypeptides are Imaged using a Fluor-S MAX Multilmager (Bio-Rad Laboratories, Hercules, CA) for quantification of modified Clostridial toxin expression levels. The size and amount of modified Clostridial toxin is determined by comparison to MagicMarkTM protein molecular weight standards (Invitrogen, Inc, Carlsbad, CA). [07021 Expression of modified Clostridial toxin is also analyzed by Western blot analysis. Protein samples purified using the procedure described above are added to 2x LDS Sample Buffer (Invitrogen, Inc, Carlsbad, CA) and are separated by MOPS polyacrylamide gel electrophoresis using NuPAGE* Novex 4-12% Bis-Tris precast polyacrylamide gels (Invitrogen, Inc, Carlsbad, CA) under denaturing, reducing conditions. Separated polypeptides are transferred from the gel onto polyvinylidene fluoride (PVDF) membranes (Invitrogen, Inc, Carlsbad, CA) by Western blotting using a Trans-Blot* SD semi-dry electrophoretic transfer cell apparatus (Bio-Rad Laboratories, Hercules, CA). PVDF membranes are blocked by incubating at room temperature for 2 hours in a solution containing 25 mM Tris-Buffered Saline (25 mM 2-amino-2-hydroxymethyl-1,3-propanediol hydrochloric acid (Tris-HCI)(pH 7.4), 137 mM sodium chloride, 2.7 mM potassium chloride), 0.1% TWEEN-20", polyoxyethylene (20) sorbitan monolaureate, 2% bovine serum albumin, 5% nonfat dry milk. Blocked membranes are incubated at 4 *C for overnight in Tris-Buffered Saline TWEEN-20* (25 mM Tris-Buffered Saline, 0.1% TWEEN-20*, polyoxyethylene (20) sorbitan monolaureate) containing appropriate primary antibodies as a probe. Primary antibody probed blots are washed three times for 15 minutes each time in Tris-Buffered Saline TWEEN-20*. Washed membranes are Incubated at room temperature for 2 hours in Tris-Buffered Saline TWEEN-20" containing an appropriate Immunoglobulin G antibody conjugated to horseradish peroxidase as a secondary antibody. Secondary antibody-probed blots are washed three times for 15 minutes each time In Tris-Buffered Saline TWEEN-20*. Signal detection of the labeled modified Clostridial toxin are visualized using the ECL PIuSTM Western Blot Detection System (Amersham Biosciences, Piscataway, NJ) and are imaged with a Typhoon 9410 Variable Mode Imager (Amersham Biosciences, Piscataway, NJ) for quantification of modified Clostridial toxin expression levels. [0703] Although aspects of the present invention have been described with reference to the disclosed embodiments, one skilled in the art will readily appreciate that the specific examples disclosed are only illustrative of these aspects and in no way limit the present invention. Various modifications can be made without departing from the spirit of the present invention. 296 of 316

Claims (91)

1. A modified Clostridial toxin comprising: a) a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) an enhanced targeting domain comprising a modified Clostridial binding domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a protease cleavage site wherein cleavage of the protease cJeavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form; and wherein the modified Clostridial binding domain exhibits enhanced binding activity for an endogenous Clostridial toxin receptor system relative to the binding activity of a naturally-occurring Clostridial binding domain from which the modified Clostridial binding domain Is derived.

2. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, In a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the Clostridial toxin translocation domain and the enhanced targeting domain.

3. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the enhanced targeting domain and the Clostridial toxin translocation domain.

4. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin translocation domain, the protease cleavage site and the Clostridial toxin enzymatic domain.

S. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin enzymatic domain, the protease cleavage site and the Clostridial toxin translocation domain.

6. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, In a linear amino-to-carboxyl single polypeptide order, the Clostridlal toxin translocation domain, the protease cleavage site, the Clostridial toxin enzymatic domain and the enhanced targeting domain. 297 of 316 WO 2006/101809 PCT/US2006/008956

7. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin translocation domain, the protease cleavage site, the enhanced targeting domain and the Ciostridial toxin enzymatic domain.

8. The modified Clostridial toxin according to Claim 1, wherein the Clostridial toxin enzymatic domain is selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

9. The modified Clostridial toxin according to Claim 1, wherein the Clostridial toxin translocation domain is selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

10. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain is selected from the group consisting of a modified BoNT/A binding domain, a modified BoNT/B binding domain, a modified BoNT/C1 binding domain, a modified BoNT/D binding domain, a modified BoNT/E binding domain, a modified BoNT/F binding domain, a modified BoNT/G binding domain and a modified TeNT binding domain.

11. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/A binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1101, Gly 1102, Leu 1105, Tyr 1111, Tyr 1112, Gly 1158, Ile 1163, Asp 1179, Glu 1203, Phe 1252, Ser 1264, Trp 1266, Tyr 1267, Gin 1270, Gly 1279 and Trp 1282 of SEQ ID NO: 1, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/A binding domain for a BoNT/A receptor system.

12. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/B binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1088, Gly 1089, Leu 1092, Tyr 1098, Tyr 1099, Gly 1142, Ile 1147, Asp 1165, Giu 1191, Ile 1240, Ser 1260, Trp 1262, Tyr 1263, Giu 1266, Gly 1277 and Trp 1280 of SEQ ID NO: 2, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/B binding domain for a BoNT/B receptor system. 298 of 316 WO 2006/101809 PCT/US2006/008956

13. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/C1 binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1102, Gly 1103, Leu 1106, Tyr 1112, Tyr 1113, Gly 1145, lie 1150, Asp 1166, Glu 1196, Ie 1247, Gly 1256, Trp 1258, Tyr 1259, His 1261, Gly 1281 and Trp 1284 of SEQ ID NO: 3, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/C1 binding domain for a BoNT/Ci receptor system.

14. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/D binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1089, Gly 1090, Leu 1093, Tyr 1099, Tyr 1100, Gly 1132, lie 1137, Asp 1153, Asn 1186, Lys 1236, Trp 1238, Arg 1239, Phe 1242, Ser 1262 and Trp 1265 of SEQ ID NO: 4, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/D binding domain for a BoNT/D receptor system.

15. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/E binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1076, Gly 1077, Leu 1080, Tyr 1086, Tyr 1087, Gly 1124, Ile 1129, Asp 1146, Giu 1172, Phe 1213, Ser 1221, Trp 1223, Tyr 1224, His 1227, Gly 1236 and Trp 1239 of SEQ ID NO: 5, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/E binding domain for a BoNT/E receptor system.

16. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/F binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1147, lie 1152, Asp 1171, Glu 1195, Phe 1237, Ser 1245, Trp 1247, Tyr 1248, Asn 1251, Gly 1260 and Trp 1263 of SEQ ID NO: 6, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified BoNT/F binding domain for a BoNT/F receptor system.

17. The modified Clostridial toxin according to Claim 10, wherein the modified BoNT/G binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1096, Gly 1097, Leu 1100, Tyr 1106, Tyr 1107, Gly 1148, lie 1153, Asp 1172, Gin 1198, lie 1245, Ser 1266, Trp 1268, Tyr 1269, Arg 1272, Gly 1283 and Trp 1285 of SEQ ID NO: 7, and any combination thereof; 299 of 316 WO 2006/101809 PCT/US2006/008956 wherein the amino acid substitution enhances the binding activity of the modified BoNT/G binding domain for a BoNT/G receptor system.

18. The modified Clostridial toxin according to Claim 10, wherein the modified TeNT binding domain comprises an amino acid substitution at a position selected from the group consisting of Trp 1118, Gly 1119, Leu 1122, Tyr 1128, Tyr 1129, Gly 1172, lie 1177, Asp 1194, Asp 1222, Thr 1270, Ser 1287, Trp 1289, Tyr 1290, His 1293, Gly 1300 and Trp 1303 of SEQ ID NO: 8, and any combination thereof; wherein the amino acid substitution enhances the binding activity of the modified TeNT binding domain for a TeNT receptor system.

19. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises at least one amino acid substitution in a 0-trefoil domain.

20. The modified Clostridial toxin according to Claim 19, wherein the amino acid substitution is located within an a-fold, a 13-fold or a y-fold of the p-trefoil domain.

21. The modified Clostridial toxin according to Claim 19, wherein the amino acid substitution is located within a 04/P5 0-hairpin turn or a 08/09 0-hairpin turn of the 1-trefoil domain.

22. The modified Clostridial toxin according to Claim 21, wherein the amino acid substitution is a glycine or a phenylalanine.

23. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises a substitution of a Clostridial toxin binding domain a-fold for an a-fold selected from the group consisting of a Clostridial botulinum serotype A HA-33 la-fold, a Ciostridial botulinum serotype B HA-33 la-fold, a Clostridial botulinum serotype C1 HA-33 la-fold, a Clostridial botulinum serotype D HA-33 la-fold, a Clostridial botulinum serotype A HA-33 2a-fold, a Clostridial botulinum serotype B HA-33 2a-fold, a Clostridial botulinum serotype C1 HA-33 2a-fold, a Clostridial botulinum serotype D HA-33 2a-fold, a Clostridial botulinum serotype A HA-17 a-fold, a Clostridial botulinum serotype B HA-17 a-fold, a Clostridial botulinum serotype C1 HA-17 a-fold, a Clostridial botulinum serotype D HA-17 a-fold, a Clostridial botulinum serotype A NTNH a-fold, a Clostridial botulinum serotype B NTNH a-fold, a Clostridial botulinum serotype C1 NTNH a-fold, a Clostridial botulinum serotype D NTNH a-fold, a Ciostridial botulinum serotype E NTNH a-fold, a Clostridial botulinum serotype F NTNH a-fold, a Clostridial botulinum serotype G NTNH a-fold, a FGF-1 a-fold, a FGF-2 a fold, a FGF-4 a-fold, a FGF-8 a-fold, a FGF-9 a-fold, a FGF-17 a-fold and a FGF-18 a-fold. 300 of 316 WO 2006/101809 PCT/US2006/008956

24. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises a substitution of a Clostridial toxin binding domain 1-fold for a 5-fold selected from the group consisting of a Clostridial botulinum serotype A HA-33 10-fold, a Clostridial botulinum serotype B HA-33 1p-fold, a Clostridial botulinum serotype C1 HA-33 1I1-fold, a Clostridial botulinum serotype D HA-33 10-fold, a Clostridial botulinum serotype A HA-33 2p-fold, a Clostridial botulinum serotype B HA-33 20-fold, a Clostridial botulinum serotype C1 HA-33 21-fold, a Clostridial botulinum serotype D HA-33 20-fold, a Clostridial botulinum serotype A HA-17 0-fold, a Clostridial botulinum serotype B HA-17 0-fold, a Clostridial botulinum serotype C1 HA-17 1-fold, a Clostridial botulinum serotype D HA-17 O-fold, a Clostridial botulinum serotype A NTNH 1-fold, a Clostridial botulinum serotype B NTNH 0-fold, a Clostridial botulinum serotype C1 NTNH 1-fold, a Clostridial botulinum serotype D NTNH 1-fold, a Clostridial botulinum serotype E NTNH p-fold, a Clostridial botulinum serotype F NTNH 0-fold, a Clostridial botulinum serotype G NTNH p-fold, a FGF-1 p-fold, a FGF-2 p fold, a FGF-4 0-fold, a FGF-8 0-fold, a FGF-9 P-fold, a FGF-17 p-fold and a FGF-18 0-fold.

25. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises a substitution of a Clostridial toxin binding domain y-fold for a y-fold selected from the group consisting of a Clostridial botulinum serotype A HA-33 ly-fold, a Clostridial botulinum serotype B HA-33 ly-fold, a Clostridial botulinum serotype C1 HA-33 ly-fold, a Clostridial botulinum serotype D HA-33 1y-fold, a Clostridial botulinum serotype A HA-33 2y-fold, a Clostridial botulinum serotype B HA-33 2y-fold, a Clostridial botulinum serotype C1 HA-33 2y-fold, a Clostridial botulinum serotype D HA-33 2y-fold, a Clostridial botulinum serotype A HA-17 y-fold, a Clostridial botulinum serotype B HA-17 y-fold, a Clostridial botulinum serotype C1 HA-17 y-fold, a Clostridial botulinum serotype D HA-17 V-fold, a Clostridial botulinum serotype A NTNH y-fold, a Clostridial botulinum serotype B NTNH y-fold, a Clostridial botulinum serotype C1 NTNH y-fold, a Clostridial botulinum serotype D NTNH y-fold, a Clostridial botulinum serotype E NTNH V-fold, a Clostridial botulinum serotype F NTNH y-fold, a Clostridial botulinum serotype G NTNH y-fold, a FGF-1 y-fold, a FGF-2 y fold, a FGF-4 y-fold, a FGF-8 y-fold, a FGF-9 y-fold, a FGF-1 7 y-fold and a FGF-1 8 V-fold.

26. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises a substitution of a Clostridial toxin binding domain P4/05 P-hairpin turn for a 04/15 p-hairpin turn selected from the group consisting of a Clostridial botulinum serotype A HA-33 14/05 0 hairpin tum, a Clostridial botulinum serotype B HA-33 104/05 0-hairpin turn, a Clostridial botulinum serotype C1 HA-33 104/p5 0-hairpin turn, a Clostridial botulinum serotype D HA-33 104/05 P-hairpin turn, a Clostridial botulinum serotype A HA-33 2p4/P5 1-hairpin turn, a Clostridial botulinum serotype B HA-33 204/P5 P-hairpin turn, a Clostridial botulinum serotype C1 HA-33 2p4/P5 P-hairpin turn, a Clostridial botulinum serotype D HA-33 214/05 P-hairpin turn, a Clostridial botulinum serotype A HA 17 4/05 1-hairpin turn, a Clostridial botulinum serotype B HA-17 14/05 P-hairpin turn, a Clostridial botulinum serotype C1 HA-17 54/05 0-hairpin turn, a Clostridial botulinum serotype D HA-17 04/05 p hairpin turn, a Clostridial botulinum serotype A NTNH 04/05 0-hairpin turn, a Clostridial botulinum 301 of 316 WO 2006/101809 PCT/US2006/008956 serotype B NTNH 0405 P-hairpin turn, a Clostridial botulinum serotype C1 NTNH 04/05 P-hairpin turn, a Clostridial botulinum serotype D NTNH 04/$5 P-hairpin turn, a Clostridial botulinum serotype E NTNH 04/05 1-hairpin turn, a Clostridial botulinurn serotype F NTNH 04/05 -hairpin turn, a Clostridial botulinum serotype G NTNH 4/05 0-hairpin turn, a FGF-1 04/05 1-hairpin turn, a FGF-2 P4/p5 p-hairpin turn, a FGF-4 04/05 P-hairpin turn, a FGF-8 04/05 p-hairpin turn, a FGF-9 04/05 (3 hairpin turn, a FGF-1 7 04/05 P-hairpin turn and a FGF-1 8 34/p5 1-hairpin turn.

27. The modified Clostridial toxin according to Claim 1, wherein the modified Clostridial toxin binding domain comprises a substitution of a Clostridial toxin binding domain 18/09 1-hairpin turn for a 08/09 P-hairpin turn selected from the group consisting of a Clostridial botulinum serotype A HA-33 08/09 p hairpin turn, a Clostridial botulinum serotype B HA-33 1$8/19 1-hairpin turn, a Clostridial botulinum serotype C1 HA-33 1 p8/09 p-hairpin turn, a Clostridial botulinum serotype D HA-33 108/P9 P-hairpin turn, a Clostridial botulinum serotype A HA-33 2p8/p9 p-hairpin turn, a Clostridial botulinum serotype B HA-33 2p8/p9 1-hairpin turn, a Clostridial botulinum serotype C1 HA-33 208/09 P-hairpin turn, a Clostridial botulinum serotype D HA-33 208/09 1-hairpin turn, a Clostridial botulinum serotype A HA 17 08/P9 p-hairpin turn, a Clostridial botulinum serotype B HA-17 08/09 P-hairpin turn, a Clostridial botulinum serotype C1 HA-1 7 18/09 P-hairpin turn, a Clostridial botulinum serotype D HA-1 7 18/09 p hairpin turn, a Ciostridial botulinum serotype A NTNH 08/09 0-hairpin turn, a Clostridial botulinum serotype B NTNH 08/19 P-hairpin turn, a Clostridial botulinum serotype C1 NTNH P8/09 P-hairpin turn, a Clostridial botulinum serotype D NTNH 08/09 1-hairpin turn, a Ciostridial botulinum serotype E NTNH 08/19 0-hairpin turn, a Clostridial botulinum serotype F NTNH 08/9 0-hairpin turn, a Clostridial botulinum serotype G NTNH 08/09 0-hairpin turn, a FGF-1 08/09 p-hairpin turn, a FGF-2 08/09 P-hairpin turn, a FGF-4 08/P9 P-hairpin turn, a FGF-8 08/09 1-hairpin turn, a FGF-9 18/19 p hairpin turn, a FGF-17 18/19 P-hairpin turn and a FGF-18 P8/P9 P-hairpin turn.

28. The modified Clostridial toxin according to Claim 1, wherein the protease cleavage site is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site.

29. The modified Clostridial toxin according to Claim 28, wherein the endogenous Clostridial toxin di chain loop protease cleavage site is selected from the group consisting of a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site and a TeNT di-chain loop protease cleavage site.

30. The modified Clostridial toxin according to Claim 28, wherein the exogenous protease cleavage site is selected from the group consisting of an enterokinase cleavage site, a Thrombin cleavage site, a Factor Xa cleavage site, a human rhinovirus 3C protease cleavage site, a tobacco etch virus protease cleavage site, a dipeptidyl aminopeptidase cleavage site, a small ubiquitin-like modifier 302 of 316 WO 2006/101809 PCT/US2006/008956 (SUMO)/ubiquitin-like protein-1(ULP-1) protease cleavage site, and a Clostridial toxin substrate cleavage she.

31. The modified Clostridial toxin according to Claim 30, wherein the Clostridial toxin substrate cleavage site is selected from the group consisting of a BoNT/A substrate cleavage site, a BoNT/B substrate cleavage site, a BoNT/C1 substrate cleavage site, a BoNT/D substrate cleavage site, a BoNT/E substrate cleavage site, a BoNT/F substrate cleavage site, a BoNT/G substrate cleavage site and a TeNT substrate cleavage site.

32. A modified Clostridial toxin comprising: a) a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) an enhanced targeting domain comprising a Clostridial non-toxin associated protein p-trefoil domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form.

33. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the Clostridial toxin translocation domain and the enhanced targeting domain.

34. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the enhanced targeting domain and the Clostridial toxin translocation domain.

35. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin translocation domain, the protease cleavage site and the Clostridial toxin enzymatic domain.

36. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin enzymatic domain, the protease cleavage site and the Clostridial toxin translocation domain. 303 of 316 WO 2006/101809 PCT/US2006/008956

37. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin translocation domain, the protease cleavage site, the Clostridial toxin enzymatic domain and the enhanced targeting domain.

38. The modified Clostridial toxin according to Claim 32, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin translocation domain, the protease cleavage site, the enhanced targeting domain and the Clostridial toxin enzymatic domain.

39. The modified Clostridial toxin according to Claim 32, wherein the Clostridial toxin enzymatic domain is selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

40. The modified Clostridial toxin according to Claim 32, wherein the Clostridial toxin translocation domain is selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

41. The modified Clostridial toxin according to Claim 32, wherein the Clostridial non-toxin associated protein P-trefoil domain is selected from the group consisting of a Clostridial botulinum serotype A HA-33 P-trefoil domain, a Clostridial botulinum serotype B HA-33 p-trefoil domain, a Ciostridial botulinum serotype C1 HA-33 P-trefoil domain, a Clostridial botulinum serotype D HA-33 p-trefoil domain, a Clostridial botulinum serotype A HA-17 P-trefol domain, a Clostridial botulinum serotype B HA-17 0-trefoil domain, a Clostridial botulinum serotype C1 HA-17 P-trefoil domain, a Clostridial botulinum serotype D HA-17 0-trefoil domain, a Clostridial botulinum serotype A NTNH P-trefoil domain, a Ciostridial botulinum serotype B NTNH 0-trefoil domain, a Clostridial botulinum serotype C1 NTNH (.-trefoil domain, a Clostridial botulinum serotype D NTNH 0-trefoil domain, a Clostridial botulinum serotype E NTNH P-trefoil domain, a Clostridial botulinum serotype F NTNH 0-trefoil domain and a Clostridial botulinum serotype G NTNH P-trefoil domain.

42. The modified Clostridial toxin according to Claim 32, wherein the protease cleavage site is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site.

43. The modified Clostridial toxin according to Claim 42, wherein the endogenous Clostridial toxin di chain loop protease cleavage site is selected from the group consisting of a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop 304 of 316 WO 2006/101809 PCT/US2006/008956 protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site and a TeNT di-chain loop protease cleavage site.

44. The modified Clostridial toxin according to Claim 42, wherein the exogenous protease cleavage site is selected from the group consisting of an enterokinase cleavage site, a Thrombin cleavage site, a Factor Xa cleavage site, a human rhinovirus 3C protease cleavage site, a tobacco etch virus protease cleavage site, a dipeptidyl aminopeptidase cleavage site, a small ubiquitin-like modifier (SUMO)/ubiquitin-like protein-1 (ULP-1) protease cleavage site, and a Clostridial toxin substrate cleavage site.

45. The modified Clostridial toxin according to Claim 44, wherein the Clostridial toxin substrate cleavage site is selected from the group consisting of a BoNT/A substrate cleavage site, a BoNT/B substrate cleavage site, a BoNT/C1 substrate cleavage site, a BoNT/D substrate cleavage site, a BoNT/E substrate cleavage site, a BoNT/F substrate cleavage site, a BoNT/G substrate cleavage site and a TeNT substrate cleavage site.

46. A modified Clostridial toxin comprising: a) a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin Intoxication process; c) an enhanced targeting domain comprising a FGF P-trefoil domain capable of selectively binding an FGFR3; and d) a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form.

47. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the Clostridial toxin translocation domain and the enhanced targeting domain.

48. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin enzymatic domain, the protease cleavage site, the enhanced targeting domain and the Clostridial toxin translocation domain. 305 of 316 WO 2006/101809 PCTIUS2006/008956

49. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin translocation domain, the protease cleavage site and the Clostridial toxin enzymatic domain.

50. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the enhanced targeting domain, the Clostridial toxin enzymatic domain, the protease cleavage site and the Clostridial toxin translocation domain.

51. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin translocation domain, the protease cleavage site, the Clostridial toxin enzymatic domain and the enhanced targeting domain.

52. The modified Clostridial toxin according to Claim 46, wherein the modified Clostridial toxin comprises, in a linear amino-to-carboxyl single polypeptide order, the Clostridial toxin translocation domain, the protease cleavage site, the enhanced targeting domain and the Clostridial toxin enzymatic domain.

53. The modified Clostridial toxin according to Claim 46, wherein the Clostridial toxin enzymatic domain Is selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

54. The modified Clostridial toxin according to Claim 46, wherein the Clostridial toxin translocation domain is selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

55. The modified Clostridial toxin according to Claim 46, wherein the FGF P-trefoil domain is selected from the group consisting of a FGF-1 p-trefoil domain, a FGF-2 P-trefoil domain, a FGF-4 p-trefoil domain, a FGF-8 p-trefoil domain, a FGF-9 p-trefoil domain, a FGF-17 p-trefoil domain and a FGF-18 p-trefoil domain.

56. The modified Clostridial toxin according to Claim 46, wherein the protease cleavage site is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site.

57. The modified Clostridial toxin according to Claim 56, wherein the endogenous Clostridial toxin di chain loop protease cleavage site is selected from the group consisting of a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop 306 of 316 WO 2006/101809 PCT/US2006/008956 protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site and a TeNT di-chain loop protease cleavage site.

58. The modified Clostridial toxin according to Claim 56, wherein the exogenous protease cleavage site is selected from the group consisting of an enterokinase cleavage site, a Thrombin cleavage site, a Factor Xa cleavage site, a human rhinovirus 3C protease cleavage site, a tobacco etch virus protease cleavage site, a dipeptidyl aminopeptidase cleavage site, a small ubiquitin-like modifier (SUMO)/ubiquitin-like protein-1 (ULP-1) protease cleavage site, and a Clostridial toxin substrate cleavage site.

59. The modified Clostridial toxin according to Claim 58, wherein the Clostridial toxin substrate cleavage site is selected from the group consisting of a BoNT/A substrate cleavage site, a BoNT/B substrate cleavage site, a BoNT/C1 substrate cleavage site, a BoNT/D substrate cleavage site, a BoNT/E substrate cleavage site, a BoNT/F substrate cleavage site, a BoNT/G substrate cleavage site and a TeNT substrate cleavage site.

60. A polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) a polynucleotide molecule encoding an enhanced targeting domain comprising a modified Clostridial binding domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin Into the di-chain form; and wherein the modified Clostridial binding domain exhibits enhanced binding activity for an endogenous Clostridial toxin receptor system relative to the binding activity of a naturally-occurring Clostridial binding domain from which the modified Clostridial binding domain is derived.

61. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes the modified Clostridial toxin of any one of Claims 2-7. 307 of 316 WO 2006/101809 PCTIUS2006/008956

62. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a Clostridial toxin enzymatic domain selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

63. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a Clostridial toxin translocation domain selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

64. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain selected from the group consisting of a modified BoNT/A binding domain, a modified BoNT/B binding domain, a modified BoNT/C1 binding domain, a modified BoNT/D binding domain, a modified BoNT/E binding domain, a modified BoNT/F binding domain, a modified BoNT/G binding domain and a modified TeNT binding domain.

65. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain comprising a substitution of a Clostridial toxin binding domain a-fold for an a-fold selected from the group consisting of a Clostridial botulinum serotype A HA-33 la-fold, a Clostridial botulinum serotype B HA-33 ia-fold, a Clostridial botulinum serotype C1 HA-33 la-fold, a Clostridial botulinum serotype D HA-33 ia-fold, a Clostridial botulinum serotype A HA-33 2a-fold, a Clostridial botulinum serotype B HA-33 2a-fold, a Clostridial botulinum serotype C1 HA-33 2a-fold, a Clostridial botulinum serotype D HA-33 2a-fold, a Clostridial botulinum serotype A HA-17 a-fold, a Clostridial botulinum serotype B HA-17 a-fold, a Clostridial botulinum serotype C1 HA-17 a-fold, a Clostridial botulinum serotype D HA-17 a-fold, a Clostridial botulinum serotype A NTNH a-fold, a Clostridial botulinum serotype B NTNH a-fold, a Clostridial botulinum serotype C1 NTNH a-fold, a Clostridial botulinum serotype D NTNH a-fold, a Clostridial botulinum serotype E NTNH a-fold, a Clostridial botulinum serotype F NTNH a-fold, a Clostridial botulinum serotype G NTNH a-fold, a FGF-1 a-fold, a FGF-2 a-fold, a FGF-4 a-fold, a FGF-8 a-fold, a FGF-9 a-fold, a FGF 17 a-fold and a FGF-18 a-fold.

66. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain comprising a substitution of a Clostridial toxin binding domain p-fold for a p-fold selected from the group consisting of a Clostridial botulinum serotype A HA 33 11p-fold, a Clostridial botulinum serotype B HA-33 1p0-fold, a Clostridial botulinum serotype C1 HA 33 10-fold, a Clostridial botulinum serotype D HA-33 11P-fold, a Clostridial botulinum serotype A HA 33 2p-fold, a Clostridial botulinum serotype B HA-33 2P-fold, a Clostridial botulinum serotype C1 HA 308 of 316 WO 2006/101809 PCT/US2006/008956 33 20-fold, a Clostridial botulinum serotype D HA-33 20-fold, a Clostridial botulinum serotype A HA 17 p-fold, a Clostridial botulinum serotype B HA-17 p-fold, a Clostridial botulinum serotype C1 HA-17 p-fold, a Clostridial botulinum serotype D HA-17 -fold, a Clostridial botulinum serotype A NTNH 1 fold, a Clostridial botulinum serotype B NTNH 0-fold, a Clostridial botulinum serotype CI NTNH 1 fold, a Clostridial botulinum serotype D NTNH -fold, a Clostridial botulinum serotype E NTNH p-fold, a Clostridial botulinum serotype F NTNH 1-fold, a Clostridial botulinum serotype G NTNH -fold, a FGF-1 1-fold, a FGF-2 P-fold, a FGF-4 1-fold, a FGF-8 p-fold, a FGF-9 P-fold, a FGF-17 p-fold and a FGF-18 0-fold.

67. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain comprising a substitution of a Clostridial toxin binding domain y-fold for a y-fold selected from the group consisting of a Clostridial botulinum serotype A HA 33 1y-fold, a Clostridial botulinum serotype B HA-33 ly-fold, a Clostridial botulinum serotype C1 HA 33 1 y-fold, a Clostridial botulinum serotype D HA-33 1 y-fold, a Clostridial botulinum serotype A HA-33 2y-fold, a Clostridial botulinum serotype B HA-33 2y-fold, a Clostridial botulinum serotype C1 HA-33 2y-fold, a Clostridial botulinum serotype D HA-33 2y-fold, a Clostidial botulinum serotype A HA-17 y fold, a Clostridial botulinum serotype B HA-17 y-fold, a Clostridial botulinum serotype C1 HA-17 y fold, a Clostridial botulinum serotype D HA-17 y-fold, a Clostridial botulinum serotype A NTNH y-fold, a Clostridial botulinum serotype B NTNH y-fold, a Clostridial botulinum serotype C1 NTNH y-fold, a Clostridial botulinum serotype D NTNH y-fold, a Clostridial botulinum serotype E NTNH y-fold, a Clostridial botulinum serotype F NTNH y-fold, a Clostridial botulinum serotype G NTNH y-fold, a FGF 1 y-fold, a FGF-2 y-fold, a FGF-4 y-fold, a FGF-8 y-fold, a FGF-9 y-fold, a FGF-17 y-fold and a FGF 18 y-fold.

68. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain comprising a substitution of a Clostridial toxin binding domain 04/05 P-hairpin turn for a 34/05 p-hairpin turn selected from the group consisting of a Clostridial botulinum serotype A HA-33 4/05 p-hairpin turn, a Clostridial botulinum serotype B HA-33 114/05 P-hairpin turn, a Clostridial botulinum serotype C1 HA-33 104/05 P-hairpin turn, a Clostridial botulinum serotype D HA-33 104/P5 p-hairpin turn, a Clostridial botulinum serotype A HA-33 204/P5 P-hairpin turn, a Clostridial botulinum serotype B HA-33 2p4/p5 p-hairpin turn, a Clostridial botulinum serotype C1 HA-33 204/p5 P-hairpin turn, a Clostridial botulinum serotype D HA-33 2P4/05 P-hairpin turn, a Clostridial botulinum serotype A HA-17 04/15 1-hairpin turn, a Clostridial botulinum serotype B HA-17 p4/05 P-hairpin turn, a Clostridial botulinum serotype C1 HA-17 p4/p5 p-hairpin turn, a Clostridial botulinum serotype D HA-17 14/15 P-hairpin turn, a Clostridial botulinum serotype A NTNH P4/p5 1-hairpin tum, a Clostridial botulinum serotype B NTNH 14/p5 P-hairpin turn, a Clostridial botulinum serotype C1 NTNH 04/P5 P-hairpin turn, a Clostridial botulinum serotype D NTNH p4/P5 p hairpin turn, a Clostridial botulinum serotype E NTNH 14/p5 p-hairpin turn, a Clostridial botulinum serotype F NTNH $4/05 p-hairpin turn, a Clostridial botulinum serotype G NTNH p4/p5 p-hairpin turn, 309 of 316 WO 2006/101809 PCTIUS2006/008956 a FGF-1 4/R5 p-hairpin turn, a FGF-2 p4/p5 p-hairpin turn, a FGF-4 P4/05 P-hairpin turn, a FGF-8 04/05 p-hairpin turn, a FGF-9 04/35 0-hairpin turn, a FGF-17 04/05 p-hairpin turn and a FGF-18 04/05 1-hairpin turn.

69. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encodes a modified Clostridial toxin binding domain comprising a substitution of a Clostridial toxin binding domain 08/$9 p-hairpin turn for a 08/$9 p-hairpin turn selected from the group consisting of a Clostridial botulinum serotype A HA-33 P8/09 p-hairpin turn, a Clostridial botulinum serotype B HA-33 108/09 P-hairpin turn, a Clostridial botulinum serotype C1 HA-33 108/09 p-hairpin turn, a Clostridial botulinum serotype D HA-33 138/09 p-hairpin turn, a Clostridial botulinum serotype A HA-33 208/09 p-hairpin turn, a Clostridial botulinum serotype B HA-33 2p8/19 p-hairpin turn, a Clostridial botulinum serotype C1 HA-33 2p8/09 p-hairpin turn, a Clostridial botulinum serotype D HA-33 2p8/p9 p-hairpin turn, a Clostridial botulinum serotype A HA-17 p8/19 P-hairpin turn, a Clostridial botulinum serotype B HA-17 18/19 P-hairpin turn, a Clostridial botulinum serotype C1 HA-17 08/09 P-hairpin turn, a Clostridial botulinum serotype D HA-1 7 $8/$9 P-hairpin turn, a Clostridial botulinum serotype A NTNH 08/09 p-hairpin turn, a Clostridial botulinum serotype B NTNH 08/19 P-hairpin turn, a Clostridial botulinum serotype C1 NTNH 08/09 0-hairpin turn, a Clostridial botulinum serotype D NTNH 08/9 0 hairpin turn, a Clostridial botulinum serotype E NTNH 8/109 1-hairpin turn, a Clostridial botulinum serotype F NTNH 58/59 P-hairpin turn, a Clostridial botulinum serotype G NTNH 18/P9 p-hairpin turn, a FGF-1 18/1p9 p-hairpin turn, a FGF-2 P8/19 p-hairpin turn, a FGF-4 08/09 P-hairpIn turn, a FGF-8 p819 p-hairpin turn, a FGF-9 08/19 P-hairpin turn, a FGF-17 18/09 p-hairpin turn and a FGF-18 P8/P9 P-hairpin turn.

70. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule encoding the protease cleavage site is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site.

71. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule comprises an expression vector.

72. A polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin Intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; 310 of 316 WO 2006/101809 PCT/US2006/008956 c) a polynucleotide molecule encoding an enhanced targeting domain comprising a Clostridial non toxin associated protein P-trefoil domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin Into the di-chain form.

73. The polynucleotide molecule according to Claim 72, wherein the polynucleotide molecule encodes a modified Clostridial toxin of any one of Claims 33-38.

74. The polynucleotide molecule according to Claim 72, wherein the polynucleotide molecule encodes a Clostridial toxin enzymatic domain selected from the group consisting of a BoNT/A enzymatic domain, a BoNTIB enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

75. The polynucleotide molecule according to Claim 72, wherein the polynucleotide molecule encodes a Clostridial toxin translocation domain selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

76. The polynucleotide molecule according to Claim 72, wherein the polynucleotide molecule encodes a Clostridial non-toxin associated protein 0-trefoil domain selected from the group consisting of a Clostridial botulinum serotype A HA-33 s-trefoil domain, a Clostridial botulinum serotype B HA-33 P trefoil domain, a Clostridial botulinum serotype C1 HA-33 p-trefoil domain, a Clostridial botulinum serotype D HA-33 0-trefoil domain, a Clostridial botulinum serotype A HA-17 p-trefoil domain, a Clostridial botulinum serotype B HA-1 7 p-trefoil domain, a Clostridial botulinum serotype C1 HA-1 7 p trefoil domain, a Clostridlal botulinum serotype D HA-17 P-trefoil domain, a Clostridial botulinum serotype A NTNH P-trefoil domain, a Clostridial botulinum serotype B NTNH 0-trefoil domain, a Clostridial botulinum serotype C1 NTNH A-trefoil domain, a Clostridial botulinum serotype D NTNH p trefoil domain, a Clostridial botulinum serotype E NTNH P-trefoil domain, a Clostridial botulinum serotype F NTNH p-trefoil domain and a Clostridial botulinum serotype G NTNH p-trefoil domain.

77. The polynucleotide molecule according to Claim 72, wherein the polynucleotlde molecule encoding the protease cleavage site Is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site. 311 of 316 WO 2006/101809 PCT/US2006/008956

78. The polynucleotide molecule according to Claim 60, wherein the polynucleotide molecule comprises an expression vector.

79. A polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) a polynucleotide molecule encoding an enhanced targeting domain comprising a FGF 0-trefoil domain capable of selectively binding an FGFR3; and d) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form.

80. The polynucleotide molecule according to Claim 79, wherein the polynucleotide molecule encodes a modified Clostridial toxin of any one of Claims 47-52.

81. The polynucleotide molecule according to Claim 79, wherein the polynucleotide molecule encodes a Clostridial toxin enzymatic domain selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

82. The polynucleotide molecule according to Claim 79, wherein the polynucleotide molecule encodes a Clostridial toxin translocation domain selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

83. The polynucleotide molecule according to Claim 79, wherein the polynucleotide molecule encodes a FGF p-trefoil domain selected from the group consisting of a FGF-1 p-trefoil domain, a FGF-2 p-trefoil domain, a FGF-4 1-trefoil domain, a FGF-8 P-trefoil domain, a FGF-9 P-trefoil domain, a FGF-17 p trefoil domain and a FGF-18 p-trefoil domain. 312 of 316 WO 2006/101809 PCT/US2006/008956

84. The polynucleotide molecule according to Claim 79, wherein the polynucleotlde molecule encoding the protease cleavage site is an endogenous Clostridial toxin di-chain loop protease cleavage site or an exogenous cleavage site.

85. The polynucleotide molecule according to Claim 79, wherein the polynucleotide molecule comprises an expression vector.

86. A method of producing a modified Clostridial toxin comprising the step of expressing a polynucleotide molecule encoding a modified Clostridial toxin in a cell, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) a polynucleotide molecule encoding an enhanced targeting domain comprising a modified Clostridial binding domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form; and wherein the modified Clostridial binding domain exhibits enhanced binding activity for an endogenous Clostridial toxin receptor system relative to the binding activity of a naturally-occurring Clostridlal binding domain from which the modified Clostridial binding domain is derived.

87. A method of producing a modified Clostridial toxin comprising the step of expressing a polynucleotide molecule encoding a modified Clostridial toxin in a cell, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) a polynucleotide molecule encoding an enhanced targeting domain comprising a Clostridial non toxin associated protein P-trefoil domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and d) a polynucleotide molecule encoding a protease cleavage site 313 of 316 WO 2006/101809 PCTIUS2006/008956 wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form.

88. A method of producing a modified Clostridial toxin comprising the step of expressing a polynucleotide molecule encoding a modified Clostridiai toxin in a cell, the polynucleotide molecule comprising: a) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; b) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; c) a polynucleotide molecule encoding an enhanced targeting domain comprising a FGF P-trefoil domain capable of selectively binding an FGFR3; and d) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin Into the di-chain form.

89. A method of producing a modified Clostridial toxin comprising the steps of: a) introducing into a cell a polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: I) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; ii) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; iii) a polynucleotide molecule encoding an enhanced targeting domain comprising a modified Clostridial binding domain capable of executing a cell binding step of a Clostridial toxin intoxication process; and iv) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form; and wherein the modified Clostridial binding domain exhibits enhanced binding activity for an endogenous Clostridial toxin receptor system relative to the binding activity of a naturally occurring Clostridial binding domain from which the modified Clostridial binding domain is derived. 314 of 316 WO 2006/101809 PCT/US2006/008956 b) expressing the modified Clostridial toxin encoded by the polynucleotide molecule.

90. A method of producing a modified Clostridial toxin comprising the steps of: a) introducing into a cell a polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: I) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; ii) a polynucleotide molecule encoding a Clostridial toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; iii) a polynucleotide molecule encoding an enhanced targeting domain comprising a Clostridial non-toxin associated protein P-trefoil domain capable of executing a cell binding step of a Clostridial toxin Intoxication process; and iv) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin Into the di-chain form. b) expressing the modified Clostridial toxin encoded by the polynucleotide molecule.

91. A method of producing a modified Clostridial toxin comprising the steps of: a) introducing into a cell a polynucleotide molecule encoding a modified Clostridial toxin, the polynucleotide molecule comprising: i) a polynucleotide molecule encoding a Clostridial toxin enzymatic domain capable of executing an enzymatic target modification step of a Clostridial toxin intoxication process; ii) a polynucleotide molecule encoding a Clostridlal toxin translocation domain capable of executing a translocation step of a Clostridial toxin intoxication process; iii) a polynucleotide molecule encoding an enhanced targeting domain comprising a FGF 0 trefoil domain capable of selectively binding an FGFR3; and iv) a polynucleotide molecule encoding a protease cleavage site wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form. b) expressing the modified Clostridial toxin encoded by the polynucleotide molecule. 315 of 316