EP0375740A1 - Complexes de peptides a stabilite augmentee - Google Patents

Complexes de peptides a stabilite augmentee

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Publication number
EP0375740A1
EP0375740A1 EP88908587A EP88908587A EP0375740A1 EP 0375740 A1 EP0375740 A1 EP 0375740A1 EP 88908587 A EP88908587 A EP 88908587A EP 88908587 A EP88908587 A EP 88908587A EP 0375740 A1 EP0375740 A1 EP 0375740A1
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EP
European Patent Office
Prior art keywords
peptide
amino acid
acid sequence
protein
interest
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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EP88908587A
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German (de)
English (en)
Inventor
Peter S. Kim
Terrence G. Oas
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Whitehead Institute for Biomedical Research
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Whitehead Institute for Biomedical Research
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K19/00—Hybrid peptides, i.e. peptides covalently bound to nucleic acids, or non-covalently bound protein-protein complexes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/81—Protease inhibitors
    • C07K14/8107—Endopeptidase (E.C. 3.4.21-99) inhibitors
    • C07K14/811—Serine protease (E.C. 3.4.21) inhibitors
    • C07K14/8114—Kunitz type inhibitors
    • C07K14/8117—Bovine/basic pancreatic trypsin inhibitor (BPTI, aprotinin)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/38—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against protease inhibitors of peptide structure
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies

Definitions

  • Proteins have a key role in essentially every biological process. For example, they serve as enzymes, function in transport and storage of many small molecules and ions, control expression of genetic information, are critical in immune response to and protection against foreign substances and are themselves antigenic (i.e., their introduction into a host which recognizes them as foreign or nonself elicits an immune response) .
  • amino acids each of which consists of a carbon atom (an alpha carbon), to which is bonded an amino group, a carboxyl group, a hydrogen atom and a distinctive side chain or R group.
  • Amino acids are linked by peptide or amide bonds, in which the alpha-carboxyl group of one amino acid is joined to the alpha amino group of a second amino acid, to form polypeptide chains.
  • Each amino acid unit within a polypeptide chain is referred to as an amino acid residue.
  • the main chain or backbone of a polypeptide chain is the regularly repeating unit
  • H of the chain in addition, there is a variable part of the chain, which is made up of the distinctive side chain or R group of each amino acid in the polypeptide.
  • the polypeptide chain generally has considerable flexibility, which results from free rotation of atoms around the bonds between them.
  • a protein molecule which is made up of one or more polypeptide chains, can, in theory, take on any one of many different three-dimensional shapes or conformations.
  • most polypeptide chains fold into only one of the possible conformations and the conformation a protein assumes under biological conditions is determined by the amino acid sequence of the polypeptide chain(s) making up the protein.
  • interactions between the amino acid side chains and between amino acids and water contribute to the force which gives one conformation of a protein particular stability.
  • Important factors contributing to the conformation taken by a given protein are the occurrence and distribution of polar and nonpolar side chains and the formation of disulfide bonds (or S-S bridges) between cysteine-SH groups close to one another in a folded polypeptide chain.
  • the result is that a protein molecule folds spontaneously into a characteristic and unique conformation (e.g., compact and globular or long and fibrous) .
  • the first of these two folding patterns results when a polypeptide chain turns regularly around itself. This results in a rigid cylinder or rod, in which the coiled peptide chain is the inner part of the rodlike structure and the amino acid side chains or R groups extend outward. Hydrogen bonds between NH groups and CO groups of the main peptide chain stabilize the alpha-helix.
  • the second of the folding pattern called a beta pleated sheet, is very different from the alpha-helix.
  • the former is a sheet in which the polypeptide chain is almost fully extended and the latter is tightly coiled. Stabilization of beta-sheets results from hydrogen bonds between NH groups and CO groups in different polypeptide chains in the protein molecule. Adjacent strands in a beta-sheet can be parallel (i.e., they run in the same direction) or anti-parallel (i.e., they run in opposite directions) . Proteins have been shown to exhibit different
  • levels of organization structurally.
  • a protein's amino acid sequence is the first level; this is often referred to as the protein's primary structure.
  • the second level of protein folding or structure is formed by hydrogen-bond interactions of amino acids which are located close to one another.
  • the alpha-helix and the beta-sheet are examples of secondary structure; many other types of secondary structure have been defined, on the basis of the dihedral angles formed between adjacent peptide bonds.
  • quaternary structure is formed by interactions between amino acid residues which are far apart in the amino acid (linear) sequence.
  • quaternary structure refers to the manner in which the multiple polypeptide chains which make up a protein are packed together.
  • the critical determinant of a protein's function is its conformation, or the three-dimensional arrangement of its components. It appears that proteins fold, and achieve their characteristic conformations, by the association or interaction of short regions or stretches in them which transiently assume an alpha-helical or beta-sheet form.
  • short peptides which have the amino acid sequence corresponding to the amino acid sequence in a region of a native or intact protein do not, under physiological conditions, assume the same conformation as does the equivalent region in the native protein.
  • peptides or protein "fragments" usually do not have the same functional characteristics (e.g., as enzymes, antibodies, antigens, etc.) as those evidenced by the intact fragment (the equivalent region in the complete or native protein).
  • short peptides fail to adopt a stable structure similar to that of the native protein under physiological conditions.
  • Peptide complexes which include at least two short peptide units corresponding in amino acid sequence to selected regions of a protein of interest and joined in such a way that the short peptide units interact with one another in much the same manner that the regions of the native or intact protein interact are the subject of the present invention, as are methods of their preparation and use.
  • Short peptide units each generally having approximately five to thirty amino acid residues and corresponding in amino acid sequence to distinct regions of a protein of interest, have been joined by covalent bonding of the short peptide units to produce peptide complexes which are more stable, under physiologic conditions, than presently-available peptides, which are individual or single peptides.
  • two short peptide units each including approximately five to 30 amino acid residues and corresponding in sequence to sequences in an intact protein which form defined secondary structure and, optionally, to sequences which correspond to sequences in other regions of the intact protein, are joined by covalent bonding.
  • the resulting peptide complex forms a structure more stable than either of the two peptide components alone.
  • two short peptide units each includ ⁇ ing a cysteine residue and corresponding to a distinct region of bovine pancreatic trypsin inhibitor (BPTI) , have been joined by means of a disulfide bond between the cysteine residue present in each.
  • One of the peptide units has 16 amino acid residues, including a cysteine residue; all or a portion of the unit corresponds in sequence to a distinct region of bovine pancreatic trypsin inhibitor (BPTI) which folds into an alpha-helix in the intact protein.
  • the other short peptide unit has 14 amino acid residues, also including a cysteine residue.
  • the amino acid se ⁇ quence of the synthetic peptide pair is homologous to a domain of the precursor of the amyloid Beta-protein characteristic of Alzheimer's disease which contains a protease-inhibitor sequence.
  • the resulting peptide complex has been shown, using the temperature dependence of circular dichroism, nuclear magnetic resonance and ultraviolet absorbance spectra as criteria for structure formation, to be more stable than individual short peptides. It has been shown not only that, as expected, the individual short peptides show little, if any, structure formation in aqueous solution, but also that the peptide complex is more stable in aqueous solution than individual short peptides.
  • Peptide complexes of the present invention can be used in the design and production of synthetic vaccines which are peptides whose sequence mimics portions of that of an intact or native protein antigen.
  • the peptide complexes are particularly valuable because they form conformations or structures which are stable under physiological conditions.
  • Such synthetic vaccines can be administered to an individual (e.g., human, other mammal or nonmammalian animal) in whom an immune response is desired.
  • peptide complexes of the present invention can be used as artificial proteins in a therapeutic, prophylactic or diagnostic context.
  • they can be used as drugs or in place of naturally-occurring proteins, such as enzymes and hormones.
  • a peptide complex of the present invention can be constructed to incorporate the func ⁇ tional component(s) or active site(s) of a naturally- occurring enzyme, alone or in combination with other selected regions of the enzyme.
  • peptide complexes of the present invention can be used for diagnostics.
  • a selected peptide complex of the present invention can be used to produce peptide antigens which are more suitable for use in diagnostic tests than are presently-available peptide antigens because of the similarity of the behavior of the peptide complex of the present invention to that of the intact/native protein against which an immune response is mounted in the body.
  • Such peptide complexes can also be used to produce antibodies capable of reacting with the complex and with the corresponding section of the intact/native protein. Such antibodies also have diagnostic applications.
  • Synthetic peptides of the present invention can, because of their homology to an Alzheimer's amyloid protein, be used to produce a diagnostic for detecting the presence of the amyloid protein in tissue and, thus, of the disease.
  • each of the two short peptide units in the peptide complex corresponds to a region of BPTI, as described previously.
  • Antibodies against the peptide complex can be produced, .using known techniques.
  • Peptide complexes of the present invention are also useful for mapping and/or screening discontinu ⁇ ous epitopes. Peptides representing discontinuous epitopes are difficult to synthesize.
  • the present invention is useful in the design and construction of peptides to discontinuous epitopes and in construction of synthetic ligands.
  • Synthetic ligands made according to the method of the present invention can be used, for example, to interfere with the ability of an infectious agent (e.g., human immunodeficiency virus, HIV) to bind to a cell receptor (e.g., on T4 lymphocytes) and, thus, prevent infection.
  • an infectious agent e.g., human immunodeficiency virus, HIV
  • a cell receptor e.g., on T4 lymphocytes
  • peptide complexes which include the catalytic subdomains or regions of a protein. For example, it is possible to determine the catalytic subdomain, or enzyme subdomain, of an enzyme of interest and produce a peptide complex of two or more short peptide units which will exhibit the enzymatic activity of the intact or native protein.
  • a synthetic analog of an immunogenic protein which is less immunogenic than the intact or native protein. This can be done by determining the necessary characteristics and sequence of the protein binding sites and producing a peptide complex which has similar characteristics but lacks the remainder of the protein, which is responsible for the immunogenicity.
  • Figure 1 represents an approach to the design of peptide complexes of the present invention.
  • Figure 2 is the H NMR spectrum of the alpha/beta peptide complex of bovine pancrease trypsin inhibitor (BPTI).
  • Figure 3 is the H NMR spectrum of the aromatic region of the alpha/beta peptide complex of BPTI.
  • Figure 4 is a graphic representation of the chemical shifts of aromatic peak A in the 1H NMR spectrum of the alpha/beta peptide complex (See Figure 3) at various temperatures.
  • Figure 5 is a graphic representation of the chemical shifts of all assigned amide and alpha protons of the alpha/beta complex (P ⁇ P ⁇ ) versus those observed for the corresponding residues in BPTI. The range of chemical shift values for amide and alpha protons in model "random coil" peptides shown with squares.
  • Figure 6 presents circular dichroism spectra of the alpha and the beta peptides and the alpha/beta peptide complex.
  • Figure 7 presents the circular dichroism ellipticity at varying temperatures and a wavelength of 222 nM of the alpha and the beta peptides and the alpha/beta peptide complex.
  • Figure 8 is a graphic represention of the tempera ⁇ ture dependence of the CD signal at 218 nm for the alpha/beta complex in the presence or absence of guanidine hydrochloride (GuHCl) .
  • the inset shows the first derivative of the temperature dependence in the absence of GuHCl.
  • Figure 9 presents ultraviolet absorbance due to tyrosine at varying temperatures and at 285.5 nM.
  • Figure 10 compares the amino acid sequence of the amyloid precursor protein (APP) domain with the amino acid sequence of the BPTI alpha/beta complex of the present invention and also presents the amino acid sequence of naturally-occurring BPTI and of bovine serum inhibitor (BSI) protein.
  • APP amyloid precursor protein
  • Figure 11 is a graphic representation of results of an assay for production of antibody to the alpha/beta peptide complex of the present invention in three rabbits injected with the complex. Pre indicates the control (pre injection) value for an animal; 1st indicates the post injection value for an animal. Animals are indicated by number (276,277,278).
  • the present invention is based on the discovery that short peptides can be joined (e.g., by covalent bonding) to form a peptide complex which interact in much the same manner as the corresponding region in the intact or native protein.
  • the present invention relates to peptide complexes which are comprised of at least two short peptide units, each of which has an amino acid sequence (primary sequence) corresponding to the amino acid sequence of a selected segment of a protein of interest and which are joined in such a manner that they interact much as the regions in the native or intact protein interact.
  • Such peptide complexes are useful as synthetic vaccines, as synthetic ligands in raising antibodies to be used in diagnostic tests, as drugs (e.g., hormones, enzymes), in epitope mapping and in designing proteins.
  • drugs e.g., hormones, enzymes
  • a key element in the development of the peptide complexes of the present invention is the joining of at least two short peptide units by covalent bonding as a means of enhancing the stability of the resulting complex.
  • the amino acid sequences of the peptide units in the complex correspond to the amino acid sequences of regions of defined secondary structure which interact in the native or intact protein.
  • the short peptides units which comprise peptide complexes of the present invention are selected, by the methods described below, on the basis of interactions occurring in the intact protein.
  • the peptide units selected in this manner correspond in sequence to segments in the intact protein which form defined secondary structure (e.g., alpha-helix, beta-sheet) .
  • the peptide units may also include sequences which correspond to other segments of the intact protein which enhance the stability of the peptide complex.
  • the sequence of a peptide unit which corresponds to a selected segment in the intact protein can be identical to that of the selected segment or, alternatively, can include one or more amino acid substitutions.
  • a substitution is by an amino acid which has the same propensity to form the secondary structure observed in the native or intact protein of interest. For example, an alanine or a serine residue can be substituted for the cysteine residue present at residue 55 of the peptide complex represented in Figure 1.
  • Bonding of the two units will generally be covalent in nature ahd, in particular, will be disulfide bonding (between at least one cysteine residue on each of the peptide units) .
  • Covalent bonding is used because the bond between the short peptide units must be strong enough to hold the units together and overcome their tendency to diffuse away from each other in solution.
  • any covalent bond which does not destroy or alter the conformation can be used (e.g., carboxyl/amino amide linkages, such as a glu/lys link) .
  • short peptide units to be incorporated into a peptide complex of the present invention can be carried out in at least two different ways: one for those proteins whose crystal structure is known and one for those proteins for which the crystal structure is not known. In both cases, the length of the short peptide units used will be defined or limited by the number of amino acid residues needed to produce stable, non-random structure under physiological conditions. Selection of short peptide units if protein crystal structure is known
  • the crystal structure of a protein of interest is assessed for defined areas of contact between protein regions. Once these areas have been defined, the location(s) of disulfide bond(s) is determined, followed by a determination of the occurrence and location of other types of contacts between protein regions.
  • sequence 1 One sequence which resulted (sequence 1) includes the 10 amino acid sequence of the alpha-helix (residues 47-56 in Figure 1) and, in addition, a 4 amino acid residue segment (residues 43-46) in which numerous contacts were made with a beta sheet.
  • sequence 2 a sequence which resulted includes 14 amino acid residues (sequence 2) .
  • peptide units corresponding in sequence to the amino acid sequence of each of these two regions in the native protein are made.
  • Such peptides can be made mechanically (i.e., on a protein synthesizing machine); can be produced using known genetic engineering techniques, in which DNA encoding each peptide is cloned or synthesized and expressed,' followed by recovery of the peptide units; or can be isolated or purified from naturally-occurring sources.
  • BPTI Bovine pancreatic trypsin inhibitor
  • BPTI is one of a series of enzymes that inhibit proteolytic activity. Travis, J. and G.A. Salvesen. Rev. Biochem. 52, 655-709 (1982) .
  • Such enzymes are important in cell growth and differentiation which requires a series of surface-related proteolytic events involving serine proteinases.
  • BPTI is a single domain protein which contains three disulfide bonds, an alpha helix, a short 3. helix and a 3-stranded beta sheet. The structure of BPTI (58 residues) has been determined in three different crystal forms.
  • Residues 47-56, inclusive are those which make up the BPTI alpha-helix.
  • Residues 43-46, inclusive, as described above, make contacts closer than 4A with residues m the beta peptide, which are ref rred to as a hydrophobic "pocket".
  • an alanine (Ala) residue was substituted at residue 55 for the cysteine (Cys) which occurs at that location in the native protein.
  • the alpha peptide used includes only one cysteine residue, rather than two, as is the case with natural BPTI.
  • beta peptide The second short peptide, referred to as beta peptide and also synthesized mechanically, has the following sequence:
  • This amino acid sequence is the same as that of the native sequence. Disulfide bonding between cysteine residues 30 and 51 was used to join the components to produce the peptide complex, referred to as the alpha/ beta complex.
  • the 30-51 disulphide connects the C-terminal ⁇ -helical region (containing Cys-51) to a strand of the central antiparallel ⁇ -sheet (containing Cys-30) .
  • the core region of the alpha/beta complex therefore includes residues corresponding to the a-helix and to a substantial part of the central antiparallel ⁇ -sheet. Residues outside this core region were also included.
  • the complex represents approximately half of BPTI (30 of 58 residues) and it includes the majority of one of the hydrophobic cores of the protein.
  • Other forms of bonding can be used to join the two or more peptide units which make up a peptide complex; any covalent bond which does not destroy or alter the conformation can be used.
  • the synthetic peptide complex of the present inven ⁇ tion is very soluble in aqueous solution and does not aggregate. As judged by circular dichroism (CD) and NMR, the peptide complex is over 90% folded in aqueous solu ⁇ tion (pH 6) at 4 ⁇ C. The structure unfolds when the disulphide bond is reduced.
  • H High Resolution Nuclear Magnetic Resonance High resolution proton (H) nuclear magnetic resonance * H NMR) spectra have been obtained for the BPTI alpha/beta complex of BPTI (described above and in Example 1) .
  • Figure 2 is the entire H NMR spectrum for the alpha beta complex and
  • Figure 3 is the aromatic chemical shift region of the H NMR spectrum tempera ⁇ tures.
  • the spectrum represented in Figure 3 is that for the left-most series of peaks (e.g., from about 6.5 to 7.5 ppm) in Figure 2.
  • the resonances shown correspond to protons on (the benzene rings found in) the side chains of the aromatic amino acids phenylalanine and tyrosine; phenylalanine occurs twice in peptide sequence 2 and once in sequence 1 and tyrosine occurs twice in the sequence 2, as shown in Figure 1.
  • one of the phenylalanine residues and both tyrosine residues present in sequence 2, as well as the phenylalanine present in sequence 1 participate in contacts closer than 4A m what is referred to as a hydrophobia "pocket.”
  • the frequencies (chemical shift) of some of the resonances change with temperature, while others do not.
  • the resonance of peak A shows a temperature-dependent chemical shift; that of peak B does not.
  • the chemical shift of A is the time average of the resonances of at least two rapidly interconverting species whose relative populations change with temperature.
  • One of these species is probably an unstructured complex while the others are likely to have structure.
  • Figure 4 shows the chemical shift of peak A at several temperatures. Many factors other than peptide structure might lead to temperature-dependent chemical shifts. However, these factors would typically give rise to a linear temperature dependence. The deviation from linearity depicted in Figure 4 for the chemical shift of peak A can be taken as evidence that the region of the peptide that gives rise to this resonance undergoes a thermal transition at about 40 C. It is likely that this thermal transition results from the loss of structure in alpha/beta complex as the temperature is raised above 40°C. This indicates the presence of structured alpha/ ' beta complex at temperatures below 40°C.
  • NOE's were observed as cross-peaks which could be unambiguously assigned (i.e., definitive assign ⁇ ments of resonances to the associated protons, and no possibility of overlap with other resonances) in NOESY spectra of the alpha/beta complex at 4°C. Cross-peaks were observed both in spectra accumulated using 250 msec and 350 msec mixing times. For comparison, the distances between the corresponding protons in the crystal struc ⁇ ture of BPTI are indicated. Wlodawer, A. et al. , . Mol ⁇ Biol., 180:301-329 (1984).
  • Circular Dichroism Circular dichroism (CD) is useful in measuring the overall helix content of peptides in solution.
  • the n >* absorbance band centered at 222 nM is due to the amide bonds found in the backbone of the peptide.
  • the CD ellipticity of this band has been used as an indicator of the alpha helix content of peptides and proteins.
  • Figure 6 shows the CD spectra of the alpha peptide unit at 0 and 60°C (5A) , the beta peptide unit at 5 C
  • Figures 7A, 7B and 7C show the CD ellipticity at 222 nM for peptides alpha, beta and alpha/beta complex, respectively, at various temperatures.
  • NMR chemical shifts a non-linear temperature dependence of
  • alpha/beta complex has much more stable non-random structure than either of its component peptides and that 0 there is likely to be significant amounts of structure present in this complex under physiological conditions.
  • CD spectras indicate that the alpha/beta complex folds into a native-like conformation in aqueous solution and that this structure can be unfolded with increasing temperature, whereas there is no evidence for substantial folded structure when the disulphide bond is reduced.
  • the thermal unfolding transition for the complex is broad, spanning over 60°C, and a fully folded baseline is not reached even at 0°C ( Figure 8) .
  • the transition is completely reversible up to 80°C provided that the sample is degassed before use, and can be eliminated by adding the denaturant, GuHCl.
  • the complex does not aggregate, as judged by gel filtration, and there is no significant dependence of the CD signal on peptide concentration over a 20-fold range.
  • the individual short peptide units i.e., the alpha peptide sequence and the beta peptide sequence
  • the alpha/beta complex does exhibit a thermal transition, as evidenced by the deviations from linearity in temperature dependence evidenced by the complex in all three measurements;
  • regions of a protein of interest which are involved in (responsible for) folding Of the protein and, thus, for stable conformation of the protein can be identified for any protein of interest.
  • Short peptide units corresponding in amino acid sequence to the selected regions can be synthesized, using known techniques. At least two of the short peptide units are then joined, preferably by covalent bonding, which can be disulfide bonding, to produce a peptide complex. The resulting complex will be more stable in aqueous solution than individual short peptides.
  • the conformation of the peptide complex can be assessed, if necessary, by one or more of the three methods described for assessment of stable structure formation of the BPTI peptide complex.
  • Alpha/beta complex formation Alpha/beta complex was produced using G-15 purified alpha and beta.
  • the oxidation of the disulfide bond was carried out in 0.1 M Tris, 0.2 M KC1 at pH 8.7, using peptide concentrations of approximately 20 mM. Creighton, T.E., Journal of Molecular Biology, 113:275-293 (1977).
  • the oxidation reaction was catalyzed in air by vigorous stirring for 30 h at 4°C.
  • the crude reaction mixture was lyophilized and stored dessicated at -20°C.
  • Alpha/beta complex was also produced by the following method: Beta peptide was reacted with oxidized glutathione (GSSG) and the mixed disulfide was purified by HPLC, to produce P-beta SSG. P-beta SSG was then reacted with P alpha to produce P alpha P beta. Alpha, beta and alpha/beta complex HPLC purification
  • Each of the peptides studied were purified by semi-preparative reverse phase HPLC using a C-18 (1 x 20 cm) column (Vydac) .
  • the peptides were eluted in 0.1% TFA in H 2 0/0.1% TFA, 30% CH 3 C in H 2 0 linear gradients optimized for each peptide.
  • the elution was monitored by __ g and fractions were collected and lyophilized.
  • the purity of each peptide, as assessed by analytical reverse phase HPLC was greater than 99%.
  • alpha beta complex was confirmed by reduction of the disulfide bond in lOmM DTT, 0.1M Tris, pH 7.0, followed by analytical reverse phase HPLC to produce peaks with retention times identical to those of alpha and beta.
  • sequences of alpha and beta were confirmed using an Applied Biosystems Model 470A gas-phase sequencer «
  • EXAMPLE 2 Homology of the alpha/beta complex of BPTI to protease inhibitor sequence within amyloid Beta-protein precursor
  • This Example illustrates that the amino acid sequence of the alpha/beta complex synthesized in this invention demonstrates homology with the protein domain containing a protease-inhibitor sequence, within the precursor of the amyloid Beta-protein characteristics of Alzheimer's disease.
  • Amyloid Beta-protein/amyloid A4 has been shown to be a peptide present in the neuritic plaques, neurofibril- lary tangles and cerebrovascular deposits in individuals with Alzheimer's disease or Down's Syndrome (trisomy 21). It may be involved in the pathogenesis of Alzheimer's disease.
  • Tanzi, R.E. et al. Nature, 331:528-530 (1988).
  • Amyloid protein has recently been shown to be encoded as part of a larger protein (amyloid protein precursor) by a gene referred to as the amyloid protein precursor (APP) gene.
  • APP amyloid protein precursor
  • Figure 10 compares the amyloid precursor protein (APP) domain with the BPTI alpha/beta complex of the present invention. Also shown are residues of naturally- ocurring bovine pancreatic typsin inhibitor precursor protein and bovine serum inhibitor protein (BSI) . The sequence of the peptides of alpha/beta complex of BPTI are shown in Figure 10 (see underlining of the BPTI sequence and of the homologous sequences of the amyloid precursor protein) .
  • APP amyloid precursor protein
  • BBI bovine serum inhibitor protein
  • Numbering is based on the predicted amyloid protein sequence as defined in Ponte, P. et al. , and Kitaguchi et al. , see id.
  • Residues homologous to the highly conserved sequences of the basic typsin inhibitor family which includes BPTI, bovine inter-alpha typsin inhibitor, human inter-alpha typsin inhibitor, sea anemone proteinase inhibitor, and Russell's viper venom basic protease inhibitor (Kitaguchi, N. , et al id) are shown in Figure 8 by the dark overlining. The basic amino acid residue (arginine) in the active site is indicated by an asterisk.
  • the CD spectra of alpha, beta and alpha-beta complex were obtained on an AVIV 6OH CD spectrophotometer.
  • Temperature was controlled using an HP 89100A thermoelectric temperature controller. Spectra were collected at various temperatures and wavelengths and were corrected by subtraction of a buffer blank collected at each temperature. The concentration of peptide was
  • a buffers consisting of 5mM potassium phos- phate, 0.1M potassium fluoride at pH 6.7 or 0.2 M sodium sulfate, 10 mM disodium hydrogen phosphate at pH 6.0.
  • Double-quantum COSY, RELAY, TOCSY and phase- sensitive NOESY spectra (800 t ⁇ X 2048 t_) were collected on a 500 MHz Bruker spectrometer at the Fox Chase Medical Center (Philadelphia, PA) with a recycle delay of 2.5 sec.
  • the mixing times for the NOESY spectra were 250 or 350 msec.
  • Peptide concentration was 15 mM.
  • a sweep width of 5 kHz was used in both dimensions, and a phase- shifted sine-bell function was used to enhance resolu- tion.
  • the ultra-violet absorbance spectrum from 325 to 250 nM of alpha beta complex was obtained at various temperatures on an AVIV Model 118DS spectrophotometer.
  • Alpha-beta complex was dissolved in the same buffer used for CD spectra to a concentration of 3 mg/ml.
  • the difference in absorbance at 285.5 nM between the spectrum obtained at various temperatures and that obtained at 2°C was calculated using spectral subtraction.
  • Peptide complexes and methods disclosed herein are useful in creating peptide complexes, which include at least two short peptide units, each of which corresponds to the amino acid sequence of selected regions of a protein of interest and which are joined in such a manner that the peptide units interact in much the same way that the regions of the intact or native protein which they "mimic" interact.
  • the peptide complexes of the present invention also mimic the function or activity of the corresponding region of the intact or native protein.
  • they can be used, as described herein, for production of antibodies directed against them.
  • Synthetic ligands produced according to this invention are especially useful in investigating protein binding sites.
  • antibodies raised against the alpha/beta BPTI can be used for detection of Alzheimer's amyloid protein and, thus, can be used in diagnostic and immunotherapeutic reagents directed against this protein.

Abstract

Complexes de peptides comportant au moins deux unités de peptides courts correspondant, en séquence d'acides aminés, aux séquences d'acides aminés des segments d'une protéine intacte d'intérêt, formant une structure secondaire définie dans la protéine intacte, et procédés permettant leur préparation. Les unités de peptides dans les complexes de peptides, se composent généralement approximativement de 5 à 30 résidus d'acides aminés en longueur et sont joints par liaison covalente, par exemple par des liaisons au bisulfure formées entre un résidu de cystéine, dans chaque unité de peptide court.
EP88908587A 1987-09-04 1988-09-01 Complexes de peptides a stabilite augmentee Ceased EP0375740A1 (fr)

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US9295387A 1987-09-04 1987-09-04
US92953 1987-09-04
US20910488A 1988-06-20 1988-06-20
US209104 1998-12-10

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EP (1) EP0375740A1 (fr)
JP (1) JPH03500408A (fr)
WO (1) WO1989001943A1 (fr)

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NL9001709A (nl) * 1990-07-27 1992-02-17 Stichting Centr Diergeneeskund Peptiden en farmaceutische preparaten met een glycoprotene hormoon agonistische of antagonistische werking.
US6287787B1 (en) * 1993-11-24 2001-09-11 Torrey Pines Institute For Molecular Studies Dimeric oligopeptide mixture sets
US6271198B1 (en) 1996-11-06 2001-08-07 Genentech, Inc. Constrained helical peptides and methods of making same
CA2337153A1 (fr) * 1998-07-21 2000-02-03 Stephen Anderson Etablissement de lien entre une sequence de gene et une fonction de gene par determination de la structure de proteine en trois dimensions (3d)

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WO1985004103A1 (fr) * 1984-03-09 1985-09-26 Scripps Clinic And Research Foundation Vaccin synthetique du virus de l'hepatite b comprenant des determinants aussi bien des cellules t que des cellules b
DK160944C (da) * 1986-01-16 1991-10-21 Novo Industri As Modificerede beta2-mikroglobuliner og farmaceutiske praeparater indeholdende disse

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WO1989001943A1 (fr) 1989-03-09

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