WO1996028558A1

WO1996028558A1 - Thermitase variants having decreased adsorption and increased hydrolysis

Info

Publication number: WO1996028558A1
Application number: PCT/US1996/003009
Authority: WO
Inventors: Philip Frederick Brode, Iii; Bobby Lee Barnett; Donn Nelton Rubingh
Original assignee: The Procter & Gamble Company
Priority date: 1995-03-09
Filing date: 1996-03-06
Publication date: 1996-09-19
Also published as: BR9607756A; CZ280097A3; HUP9802069A2; MX9706846A; EP0815244A1; CN1183118A; MA23819A1; AU5182996A; ZA961822B; IL117352A0; IN187236B; JPH11501816A; CA2214578A1; HUP9802069A3

Abstract

The present invention relates to Thermitase variants having a modified amino acid sequence of wild-type Thermitase amino acid sequence, the wild-type amino acid sequence comprising a first loop region, a second loop region, a third loop region, a fourth loop region, a fifth loop region and a sixth loop region; wherein the modified amino acid sequence comprises different amino acids than that occurring in wild-type Thermitase (i.e., substitution) at specifically identified positions in one or more of the loop regions whereby the Thermitase variant has decreased adsorption to, and increased hydrolysis of, an insoluble substrate as compared to the wild-type Thermitase. The present invention also relates to DNA sequences encoding such Thermitase variants. The present invention also relates to compositions comprising such Thermitase variants for cleaning a variety of surfaces.

Description

THERMITASE VARIANTS HAVING DECREASED ADSORPTION AND INCREASED HYDROLYSIS

TECHNICAL FIELD

The present invention relates to novel enzyme variants useful in a variety of cleaning compositions, and DNA sequences encoding such enzyme variants

BACKGROUND

Enzymes make up the largest class of naturally occurring proteins Each class of enzyme generally catalyzes (accelerates a reaction without being consumed) a different kind of chemical reaction One class of enzymes known as proteases, are known for their ability to hydrolyze (break down a compound into two or more simpler compounds with the uptake of the H and OH parts of a water molecule on either side of the chemical bond cleaved) other proteins This ability to hydrolyze proteins has been taken advantage of by incorporating naturally occurring and protein engineered proteases as an additive to laundry detergent preparations Many stains on clothes are proteinaceous and wide-specificity proteases can substantially improve removal of such stains

Unfortunately, the efficacy level of these proteins in their natural bacterial environment, frequently does not translate into the relatively unnatural wash environment Specifically, protease characteristics such as thermal stability, pH stability, oxidative stability and substrate specificity are not necessarily optimized for utilization outside the natural environment of the enzyme

The amino acid sequence of the protease determines the characteristics of the protease A change of the amino acid sequence of the protease may alter the properties of the enzyme to varying degrees, or may even inactivate the enzyme, depending upon the location, nature and/or magnitude of the change in the amino acid sequence Several approaches have been taken to alter the wild-type amino acid sequence of proteases in an attempt to improve their properties, with the goal of increasing the efficacy of the protease in the wash environment These approaches include altering the amino acid sequence to enhance thermal stability and to improve oxidation stability under quite diverse conditions

Despite the variety of approaches described in the art, there is a continuing need for new effective variants of proteases useful for cleaning a variety of surfaces

Objects of the Present Invention

It is an object of the present invention to provide Thermitase enzyme variants having improved hydrolysis versus the wild-type of the enzyme

It is also an object of the present invention to provide cleaning compositions comprising these subtilisin enzyme variants.

SUMMARY

The present invention relates to Thermitase variants having a modified amino acid sequence of wild-type Thermitase amino acid sequence, the wild-type amino acid sequence comprising a first loop region, a second loop region, a third loop region, a fourth loop region and a fifth loop region, wherein the modified amino acid sequence comprises different amino acids than that occurring in wild-type Thermitase (i.e., substitution) at specifically identified positions in one or more of the loop regions whereby the Thermitase variant has decreased adsorption to, and increased hydrolysis of, an insoluble substrate as compared to the wild-type Thermitase The present invention also relates to DNA sequences encoding such Thermitase variants The present invention also relates to compositions comprising such Thermitase variants for cleaning a variety of surfaces.

DESCRIPTION

I. Thermitase Variants

This invention pertains to subtilisin enzymes, in particular Thermitase, that have been modified by mutating the various nucleotide sequences that code for the enzyme, thereby modifying the amino acid sequence of the enzyme. The modified subtilisin enzymes (hereinafter, "Thermitase variants") of the present invention have decreased adsorption to and increased hydrolysis of an insoluble substrate as compared to the wild-type subtilisin. The present invention also pertains to DNA sequences encoding for such Thermitase variants.

The subtilisin enzymes of this invention belong to a class of enzymes known as proteases. A protease is a catalyst for the cleavage of peptide bonds One type of protease is a serine protease. A serine protease is distinguished by the fact that there is an essential serine residue at the active site

The observation that an enzyme's rate of hydrolysis of soluble substrates increases with enzyme concentration is well documented It would therefore seem plausible that for surface bound substrates, such as is encountered in many cleaning applications, the rate of hydrolysis would increase with increasing surface concentration. This has been shown to be the case (Brode, P.F. III and D. S. Rauch, LANGMUIR, "Subtilisin BPN': Activity on an Immobilized Substrate", Vol. 8, pp. 1325-1329 (1992)) In fact, a linear dependence of rate upon surface concentration was found for insoluble substrates when the surface concentration of the enzyme was varied (Rubingh, D N. and M. D. Bauer, "Catalysis of Hydrolysis by Proteases at the Protein-Solution Interface." in POLYMER SOLUTIONS, BLENDS AND INTERFACES. Ed. by I. Noda and D. N. Rubingh. Elsevier, p. 464 (1992)) Surprisingly, when seeking to apply this principle in the search for variant proteases which give better cleaning performance, we did not find that enzymes which adsorb more give better performance In fact, we surprisingly determined the opposite to be the case: decreased adsorption by an enzyme to a substrate resulted in increased hydrolysis of the substrate (i.e., better cleaning performance).

While not wishing to be bound by theory, it is believed that improved performance, when comparing one variant to another, is a result of the fact that enzymes which adsorb less are also less tightly bound and therefore more highly mobile on the surface from which the insoluble protein substrate is to be removed. At comparable enzyme solution concentrations this increased mobility is sufficient to outweigh any advantage that is conferred by delivering a higher concentration of enzyme to the surface

The mutations described herein are designed to change (i.e., decrease) the adsorption of the enzyme to surface-bound soils In Thermitase, certain amino acids form exterior loops on the enzyme molecule. For purposes of discussion, these loops shall be referred to as first, second, third, fourth and fifth loop regions. Specifically, positions 66- 73 form the first loop region; positions 103-115 form the second loop region; positions 134-141 form the third loop region; positions 162-171 form the fourth loop region; positions 191-195 form the fifth loop region; and positions 204-224 form the sixth loop region (position numbering analogous to positions in the amino acid sequence for wild-type subtilisin Thermitase (SEQ ID NO:1 )). It is believed that these loop regions play a significant role in the adsorption of the enzyme molecule to a surface-bound peptide, and specific mutations in one or more of these loop regions will have a significant effect on this adsorption. While not wishing to be bound by theory, it is believed that the loop regions are important to the adsorption of the Thermitase molecule for at least two reasons. First, the amino acids which comprise the loop regions can make close contacts with any surfaces to which the molecule is exposed. Second, the proximity of the loop regions to the active-site and binding pocket of the Thermitase molecule gives them a role in the catalytically productive adsorption of the enzyme to surface-bound substrates (peptides/protein soils).

As used herein, "variant" means an enzyme having an amino acid sequence which differs from that of wild-type.

As used herein, "mutant Thermitase DNA" means a DNA sequence coding for a Thermitase variant.

As used herein, "wild-type Thermitase" refers to an enzyme represented by SEQ ID NO:1. The amino acid sequence for Thermitase is further described by Meloun, B., Baudys, M., Kostka, V., Hausdorf, G., Frommel, C, and Hohne, W.E., FEBS LETT., Vol. 183, pp. 195-200 (1985), incorporated herein by reference.

As used herein, the term "Thermitase wild-type amino acid sequence" encompasses SEQ ID NO:1 as well as SEQ ID NO:1 having modifications to the amino acid sequence other than at any of positions 66, 67, 68, 69, 70, 72, 73, 103, 104, 105, 106, 107, 108, 109, 110, 111 , 112, 113, 114, 115, 134, 135, 136, 137, 138, 139, 140, 141 , 162, 163, 164, 165, 166, 167, 168, 169, 170, 171 , 191 , 192,193,194, 195, 204, 205, 206, 207, 208, 209, 210, 211 , 212, 213, 214, 215, 216, 217, 218, 219, 220, 221 , 222, 223 or 224.

As used herein, "more hydrophilic amino acid" refers to any other amino acid having greater hydrophilicity than a subject amino acid with reference to the hydrophilicity table below. The following hydrophilicity table (Table 1 ) lists amino acids in descending order of increasing hydrophilicity (see Hopp, T.P., and Woods, K.R., "Prediction of Protein Antigenic Determinants from Amino Acid Sequences", PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCE USA, Vol. 78, pp. 3824-3828, 1981 , incorporated herein by reference).

Example 1

Mutant Thermitase DNA

A phagemid ("TP") containing the wild type Thermitase gene is constructed The 2 8 Kbp Pvu II restriction enzyme fragment of plasmid pUC119, (Vieira, J and Messing, J , "Production of Single-Stranded Plasmid DNA", 153 METHODS IN ENZYMOLOGY 3-11 (1989)) is cloned into the Pvu II site of plasmid pUB110 (Bacillus Genetic Stock Center, Columbus OH 1 E9) The pUC119-pUB110 hybrid plasmid is named pJMA601 Into the 8amH1 restriction site of PJMA601 is cloned the polymerase chain reaction-amplified Thermitase gene gene giving TP Phagemid TP is transformed into Escherichia coli Ung- strain CJ236 and a single stranded uracil-contaming DNA template is produced using the VCSM13 helper phage (Kunkel, T.A., J D Roberts and R A Zakour, "Rapid and efficient site-specific mutagenesis without phenotypic selection", METHODS IN ENZYMOLOGY, Vol 154, pp 367-382, (1987), as modified by Yuckenberg, P.D., F Witney, J Geisselsoder and J. McClary, "Site-directed in vitro mutagenesis using uracil-contaming DNA and phagemid vectors", DIRECTED MUTAGENESIS - A PRACTICAL APPROACH, ed M.J McPherson, pp. 27-48, (1991 ); both of which are incorporated herein by reference) A single primer site-directed mutagenesis modification of the method of Zoller and Smith (Zoller, M. J., and M. Smith, "Oligonucleotide-directed mutagenesis using M13-derived vectors: an efficient and general procedure for the production of point mutations in any fragment of DNA", NUCLEIC ACIDS RESEARCH, Vol 10, pp 6487-6500, (1982), incorporated herein by reference) is used to produce all mutants (basically as presented by Yuckenberg, et al. , 1991 , above). Oligonucleotides are made using an Applied Biosystem Inc. 380B DNA synthesizer Mutagenesis reaction products are transformed into Escherichia coli strain MM294 (American Type Culture Collection E. coli 33625) All mutants are confirmed by DNA sequencing and the isolated DNA is transformed into the Bacillus subtilis expression strain BG2036 (Yang, M Y., E Ferrari and D. J. Henner, (1984), "Cloning of the Neutral Protease Gene of Bacillus subtilis and the Use of the Cloned Gene to Create an In Vitro-derived Deletion Mutation", JOURNAL OF BACTERIOLOGY, Vol 160, pp 15-21 ) For some of the mutants a modified TP with a frameshift-stop codon mutation in the corresponding loop is used to produce the uracil template Oligonucleotides are designed to restore the proper reading frame and to encode for random substitutions at positions 66, 67, 68, 69, 70, 72, 73, 103, 104, 105, 106, 107, 108, 109, 110, 111 , 112, 113, 114, 115, 134, 135, 136, 137, 138, 139, 140, 141 , 162, 163, 164, 165, 166, 167, 168, 169, 170, 171 , 191 , 192,193,194, 195, 204, 205, 206, 207, 208, 209, 210, 211 , 212, 213, 214, 215, 216, 217, 218, 219, 220, 221 , 222, 223 or 224 (equimolar and/or variable mixtures of all four nucleotides for all three bases at these codons) Mutations that correct for the frameshift-stop and produce a functional enzyme are identified by their ability to digest casein. The random substitutions are determined by DNA sequencing.

Example 2

Fermentation

The Bacillus subtilis cells (BG2036) containing a subtilisin mutant of interest are grown to mid-log phase in a one liter culture of LB-glucose broth and inoculated into a Biostat ED fermenter (B Braun Biotech, Inc., Allentown, Pennsylvania) in a total volume of 10 liters The fermentation media contains Yeast Extract, starch, antifoam, buffers and trace minerals (see FERMENTATION A PRACTICAL APPROACH, Ed. B McNeil and L M Harvey, 1990) The broth is kept at a constant pH of 7.0 during the fermentation run. Chloramphenical is added for antibiotic selection of mutagenized plasmid The cells are grown overnight at 37°C to an A₆₀₀ of about 60 and harvested. Example 3

Purification

The fermentation broth is taken through the following steps to obtain pure enzyme The broth is cleared of Bacillus subtilis cells by centnfugation, and clarified by removing fine particulates with a 100K cutoff membrane This is followed by concentration on a 10K cutoff membrane, and flow dialysis to reduce the ionic strength and adjust the pH to 5 5 using 0 025M MES buffer (2-(N-morpholino)ethanesulfonic acid) The enzyme is further purified by loading it onto either a cation exchange chromatography column or an affinity adsorption chromatography column and eluting it from the column with a NaCl or a propylene glycol gradient (see Scopes, R. K. , PROTEIN PURIFICATION PRINCIPLES AND PRACTICE, Springer-Verlag, New York (1984), incorporated herein by reference)

The pNA assay (DelMar, E.G., C Largman, J W Brodrick and M. C . Geokas, ANAL BIOCHEM , Vol 99, pp 316-320, (1979), incorporated herein by reference) is used to determine the active enzyme concentration for fractions collected during gradient elution This assay measures the rate at which p-nitroaniline is released as the enzyme hydrolyzes the soluble synthetic substrate, succinyl-alanine-alanine-proline-phenylalanine-p-nitroanilide (sAAPF-pNA) The rate of production of yellow color from the hydrolysis reaction is measured at 410 nm on a spectrophotometer and is proportional to the active enzyme concentration In addition, absorbance measurements at 280 nm are used to determine the total protein concentration The active enzyme/total-protein ratio gives the enzyme purity, and is used to identify fractions to be pooled for the stock solution

To avoid autolysis of the enzyme during storage, an equal weight of propylene glycol is added to the pooled fractions obtained from the chromatography column Upon completion of the purification procedure the purity of the stock enzyme solution is checked with SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) and the absolute enzyme concentration is determined via an active site titration method using trypsm inhibitor type ll-T turkey egg white purchased from Sigma Chemical Company (St. Louis, Missouri) The measured conversion factors will show which changes made in the enzyme molecule at the various positions result in the enzyme variant having increased activity over the wild-type, against the soluble substrate pNA

In preparation for use, the enzyme stock solution is eluted through a Sephadex-G25 (Pharmacia, Piscataway, New Jersey) size exclusion column to remove the propylene glycol and exchange the buffer. The MES buffer in the enzyme stock solution is exchanged for 0.1 M Tris buffer (Tris(hydroxymethyl-aminomethane) containing 0.01 M CaCl₂ and pH adjusted to 8.6 with HCl. All experiments are carried out at pH 8.6 in Tris buffer thermostated at 25°C.

H. Characterization of enzyme variants

Example 4

Model Surface Preparation

Aminopropyl controlled pore glass (CPG) purchased from CPG Inc. (Fairfield, New Jersey) is used as a support for covalently attaching the sAAPF-pNA substrate purchased from Bachem, Inc. (Torrence, California). The reaction is carried out in dimethyl sulfoxide and (1-ethyl-3-[3- (dimethylamino)propyl] carbodiimide hydrochloride) (EDC) is used as a coupling agent. Upon completion (monitored by pNA assay), the excess solvent is removed, and the CPG:sAAPF-pNA is rinsed with dimethyl sulfoxide (DMSO) and doubly-distilled water. This is followed by oven drying with a N2 purge at about 70°C. The reaction scheme and preparation of the immobilized substrate are conducted as described by Brode, P.F. III, and D.S. Rauch, "Subtilisin BPN': Activity on an Immobilized Substrate," LANGMUIR, Vol. 8, p. 1325-1329, (1992), incorporated herein by reference.

The CPG surface will have 62,000 ± 7,000 pNA molecules/μm². The surface area will remain unchanged from the value of 50.0m2/g reported by CPG Inc. for the CPG as received. This suggests that the procedure used to add sAAPF-pNA to CPG does not damage the porous structure (mean diameter is 486 Å).

Example 5

Surface Hydrolysis Assay

Using CPG:sAAPF-pNA, adsorption of an enzyme variant and hydrolysis of a CPG-bound peptide can be measured in a single experiment. A small volume of enzyme variant stock solution is added to a flask containing Tris buffer and CPG:sAAPF-pNA which has been degassed. The flask is shaken on a wrist-action shaker for a period of 90 minutes during which the shaker is stopped at various time intervals (for example, every 2 minutes during the early stages of adsorption hydrolysis - e.g., the first 20 minutes - and every 10 minutes towards the end of the experiment) The CPG:sAAPF-pNA is allowed to settle and the solution is sampled Both the experimental procedure and the calculation of the adsorption and hydrolysis are conducted as described by Brode et al. , 1992. above

All enzymes are monitored for stability against autolysis and should show no appreciable autolytic loss over the time course of this experiment Therefore, enzyme adsorption can be determined by measuring solution depletion The difference between the initial enzyme variant concentration and the concentration measured at each individual time point gives the amount of enzyme variant adsorbed The amount of pNA hydrolyzed from the surface is measured by taking an absorbance reading on an aliquot of the sample at 410 nm The total amount of pNA hydrolyzed is calculated by adding the amount sampled and the amount remaining in the flask This value is corrected by subtracting the amount of pNA that is hydrolyzed by Tris buffer at pH 8.6 when no enzyme is present. This base-hydrolysis ranges from 7-29% of the total hydrolysis depending on the efficiency of the enzyme

Example 6

Soluble Substrate Kinetic Analysis

The rates of hydrolysis of the soluble substrate sAAPF-pNA are monitored by measuring the adsorbance increase as a function of time at 410 nm on a DU-70 spectrophotometer. The enzyme concentration is held constant and is prepared to be in the range of 6-10 nanomolar while the substrate concentration is varied from 90-700 μM sAAPF-pNA for each kinetic determination. An adsorbance data point is taken each second over a period of 900 seconds and the data are transferred to a LOTUS™ spreadsheet (Lotus Development Corporation, Cambridge, Massachusetts). Analysis for kinetic parameters is conducted by the standard Lineweaver Burk analysis in which the data in the initial part of the run (generally the first minute) are fit to a linear regression curve to give v₀. The v₀ and s₀ data are plotted in the standard inverse fashion to give KM and k_cat. I. Example Thermitase variants

Thermitase variants of the present invention which have decreased adsorption to and increased hydrolysis of surface bound substrates are exemplified in Tables 2-36, below. In describing the specific mutations, the original amino acid occurring in wild-type is given first, the position number second, and the substituted amino acid third.

II. Cleaning Compositions

In ano

her embodiment of the present invention, an effective amount of one or more of the enzyme variants are included in compositions useful for cleaning a variety of surfaces in need of proteinaceous stain removal. Such cleaning compositions include detergent compositions for cleaning hard surfaces, unlimited in form (e.g., liquid and granular); detergent compositions for cleaning fabrics, unlimited in form (e.g., granular, liquid and bar formulations); dishwashing compositions (unlimited in form); oral cleaning compositions, unlimited in form (e.g., dentifrice, toothpaste and mouthwash formulations); denture cleaning compositions, unlimited in form (e.g., liquid, tablet); and contact lens cleaning compositions, unlimited in form (e.g., liquid, tablet).

The cleaning compositions also comprise, in addition to the Thermitase variants described hereinbefore, one or more cleaning composition materials compatible with the protease enzyme, the term "cleaning composition material", as used herein, means any liquid, solid or gaseous material selected for the particular type of cleaning composition desired and the form of the product (e.g., liquid, granule, bar, spray, stick, paste, gel), which materials are also compatible with the Thermitase variant used in the composition, the specific selection of cleaning composition materials are readily made by considering the surface material to be cleaned, the desired form of the composition for the cleaning condition during use (e.g., through the wash detergent use). The term "compatible", as used herein, means the cleaning composition materials do not reduce the proteolytic activity of the Thermitase variant to such an extent that the protease is not effective as desired during normal use situations. Specific cleaning composition materials are exemplified in detail hereinafter.

As used herein, "effective amount of enzyme variant" refers to the quantity of enzyme variant necessary to achieve the enzymatic activity necessary in the specific cleaning composition. Such effective amounts are readily ascertained by one of ordinary skill in the art and is based on many factors, such as the particular enzyme variant used, the cleaning application, the specific composition of the cleaning composition, and whether a liquid or dry (e.g., granular, bar) composition is required, and the like. Preferably the cleaning compositions comprise from about 0.0001 % to about 10% of one or more enzyme variants of the present invention, more preferably from about 0.001% to about 1 %, more preferably still from about 0.01 % to about 0.1 %. Several examples of various cleaning compositions wherein the enzyme variants may be employed are discussed in further detail below. All parts, percentages and ratios used herein are by weight unless otherwise specified.

As used herein, "non-fabric cleaning compositions" include hard surface cleaning compositions, dishwashing compositions, oral cleaning compositions, denture cleaning compositions and contact lens cleaning compositions.

A. Cleaning Compositions for Hard Surfaces. Dishes and Fabrics

The enzyme variants of the present invention can be used in a variety of detergent compositions where high sudsing and good insoluble substrate removal are desired. Thus the enzyme variants can be used with various conventional ingredients to provide fully-formulated hard-surface cleaners, dishwashing compositions, fabric laundering compositions and the like. Such compositions can be in the form of liquids, granules, bars and the like. Such compositions can be formulated as modern "concentrated" detergents which contain as much as 30%-60% by weight of surfactants.

The cleaning compositions herein can optionally, and preferably, contain various anionic, nonionic, zwitterionic, etc., surfactants. Such surfactants are typically present at levels of from about 5% to about 35% of the compositions.

Nonlimiting examples of surfactants useful herein include the conventional C₁₁-C₁₈ alkyl benzene sulfonates and primary and random alkyl sulfates, the C₁₀-C_{1 8} secondary (2,3) alkyl sulfates of the formulas CH₃(CH₂)x(CHOSO₃)-M⁺)CH₃ and CH₃(CH₂)y(CHOSO₃-M⁺) CH₂CH₃ wherein x and (y+1 ) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, the C _{1 0}-C₁₈ alkyl alkoxy sulfates (especially EO 1 -5 ethoxy sulfates), C _{1 0}-C_{1 8} alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates), the C₁₀-C_{1 8} alkyl polyglycosides, and their corresponding sulfated polyglycosides, C₁₂-C _{1 8} alpha-sulfonated fatty acid esters, C₁₂-C_{1 8} alkyl and alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C ₁₂-C ₁₈ betaines and sulfobetaines ("sultaines"), C _{1 0}-C _{1 8} amine oxides, and the like. The alkyl alkoxy sulfates (AES) and alkyl alkoxy carboxylates (AEC) are preferred herein. (Use of such surfactants in combination with the aforesaid amine oxide and/or betaine or sultaine surfactants is also preferred, depending on the desires of the formulator.) Other conventional useful surfactants are listed in standard texts. Particularly useful surfactants include the C₁₀-C₁₈ N-methyl glucamides disclosed in US Patent 5, 194,639, Connor et al., issued March 16, 1993, incorporated herein by reference.

A wide variety of other ingredients useful in detergent cleaning compositions can be included in the compositions herein, including other active ingredients, carriers, hydrotropes, processing aids, dyes or pigments, solvents for liquid formulations, etc. If an additional increment of sudsing is desired, suds boosters such as the C₁₀-C₁₆ alkolamides can be incorporated into the compositions, typically at about 1 % to about 10% levels. The C₁₀-C₁₄ monoethanol and diethanol amides illustrate a typical class of such suds boosters. Use of such suds boosters with high sudsing adjunct surfactants such as the amine oxides, betaines and sultaines noted above is also advantageous. If desired, soluble magnesium salts such as MgCl₂, MgSO₄, and the like, can be added at levels of, typically, from about 0.1 % to about 2%, to provide additionally sudsing.

The liquid detergent compositions herein can contain water and other solvents as carriers. Low molecular weight primary or secondary alcohols exemplified by methanol, ethanol, propanol, and isopropanol are suitable. Monohydnc alcohols are preferred for solubilizing surfactants, but polyols such as those containing from about 2 to about 6 carbon atoms and from about 2 to about 6 hydroxy groups (e.g., 1 ,3-propanediol, ethylene glycol, glycerine, and 1 ,2-propanediol) can also be used. The compositions may contain from about 5% to about 90%, typically from about 10% to about 50% of such carriers.

The detergent compositions herein will preferably be formulated such that during use in aqueous cleaning operations, the wash water will have a pH between about 6.8 and about 11.0. Finished products thus are typically formulated at this range. Techniques for controlling pH at recommended usage levels include the use of buffers, alkalis, acids, etc., and are well known to those skilled in the art.

When formulating the hard surface cleaning compositions and fabric cleaning compositions of the present invention, the formulator may wish to employ various builders at levels from about 5% to about 50% by weight. Typical builders include the 1 -10 micron zeolites, polycarboxylates such as citrate and oxydisuccinates, layered silicates, phosphates, and the like. Other conventional builders are listed in standard formularies.

Likewise, the formulator may wish to employ various additional enzymes, such as cellulases, lipases, amylases and proteases in such compositions, typically at levels of from about 0.001 % to about 1 % by weight. Various detersive and fabric care enzymes are well-known in the layndry detergent art.

Various bleaching compounds, such as the percarbonates, perborates and the like, can be used in such compositions, typically at levels from about 1 % to about 15% by weight. If desired, such compositions can also contain bleach activators such as tetraacetyl ethylenediamine, nonanoyloxybenzene sulfonate, and the like, which are also known in the art. Usage levels typically range from about 1 % to about 10% by weight.

Various soil release agents, especially of the anionic oligoester type, various chelating agents, especially the aminophosphonates and ethylenediaminedisuccinates, various clay soil removal agents, especially ethoxylated tetraethylene pentamine, various dispersing agents, especially polyacrylates and polyasparatates, various brighteners, especially anionic brighteners, various suds suppressors, especially silicones and secondary alcohols, various fabric softeners, especially smectite clays, and the like can all be used in such compositions at levels ranging from about 1 % to about 35% by weight Standard formularies and published patents contain multiple, detailed descriptions of such conventional materials

Enzyme stabilizers may also be used in the cleaning compositions Such enzyme stabilizers include propylene glycol (preferably from about 1% to about 10%), sodium formate (preferably from about 0 1 % to about 1 %) and calcium formate (preferably from about 0 1 % to about 1 %)

1 Hard surface cleaning compositions

As used herein "hard surface cleaning composition" refers to liquid and granular detergent compositions for cleaning hard surfaces such as floors, walls, bathroom tile, and the like Hard surface cleaning compositions of the present invention comprise an effective amount of one or more enzyme variants of the present invention, preferably from about 0 001 % to about 10%, more preferably from about 01 % to about 5%, more preferably still from about 05% to about 1% by weight of active enzyme of the composition In addition to comprising one or more of the enzyme variants, such hard surface cleaning compositions typically comprise a surfactant and a water-soluble sequestering builder In certain specialized products such as spray window cleaners, however, the surfactants are sometimes not used since they may produce a filmy/streaky residue on the glass surface

The surfactant component, when present, may comprise as little as 0 1 % of the compositions herein, but typically the compositions will contain from about 0.25% to about 10%, more preferably from about 1 % to about 5% of surfactant.

Typically the compositions will contain from about 0 5% to about 50% of a detergency builder, preferably from about 1 % to about 10%

Preferably the pH should be in the range of about 8 to 12 Conventional pH adjustment agents such as sodium hydroxide, sodium carbonate or hydrochloric acid can be used if adjustment is necessary

Solvents may be included in the compositions Useful solvents include, but are not limited to, glycol ethers such as diethyleneglycol monohexyl ether, diethyleneglycol monobutyl ether, ethyleneglycol monobutyl ether, ethyleneglycol monohexyl ether, propyleneglycol monobutyl ether, dipropyleneglycol monobutyl ether, and diols such as 2,2,4-trimethyl-1 ,3-pentanediol and 2-ethyl-1 ,3-hexanediol. When used, such solvents are typically present at levels of from about 0.5% to about 15%, preferably from about 3% to about 11 %.

Additionally, highly volatile solvents such as isopropanol or ethanol can be used in the present compositions to facilitate faster evaporation of the composition from surfaces when the surface is not rinsed after "full strength" application of the composition to the surface. When used, volatile solvents are typically present at levels of from about 2% to about 12% in the compositions.

The hard surface cleaning composition embodiment of the present invention is illustrated by the following examples.

In Examples 7-10, the Thermitase variants recited in Tables 2-36, among others, are substituted for Gln66Asn, with substantially similar results.

In Examples 11-12, any combination of the Thermitase variants recited in Tables 2-36, among others, are substituted for Gln66Asn and Gly206Asn, with substantially similar results.

2. Dishwashing Compositions

In another embodiment of the present invention, dishwashing compositions comprise one or more enzyme variants of the present invention. As used herein, "dishwashing composition" refers to all forms for compositions for cleaning dishes, including but not limited to, granular and liquid forms. The dishwashing composition embodiment of the present invention is illustrated by the following examples.

3. Fabric cleaning compositions

In another embodiment of the present invention, fabric cleaning compositions comprise one or more enzyme variants of the present invention. As used herein, "fabric cleaning composition" refers to all forms for detergent compositions for cleaning fabrics, including but not limited to, granular, liquid and bar forms. Preferred fabric cleaning compositions are those in the liquid form.

a. Granular fabric cleaning compositions

The granular fabric cleaning compositions of the present invention contain an effective amount of one or more enzyme variants of the present invention, preferably from about 0.001 % to about 10%, more preferably from about 0 005% to about 5%, more preferably from about 0 01 % to about 1 % by weight of active enzyme of the composition In addition to one or more enzyme variants, the granular fabric cleaning compositions typically comprise at least one surfactant, one or more builders, and, in some cases, a bleaching agent

The granular fabric cleaning composition embodiment of the present invention is illustrated by the following examples

b. Liguid fabric cleaning compositions

Liquid fabric cleaning compositions of the present invention comprise an effective amount of one or more enzyme variants of the present invention, preferably from about 0 005% to about 5%, more preferably from about 0 01 % to about 1 %, by weight of active enzyme of the composition Such liquid fabric cleaning compositions typically additionally comprise an anionic surfactant, a fatty acid, a water-soluble detergency builder and water

The liquid fabric cleaning composition embodiment of the present invention is illustrated by the following examples

c. Bar fabric cleaning compositions

Bar fabric cleaning compositions of the present invention suitable for hand-washing soiled fabrics contain an effective amount of one or more enzyme variants of the present invention, preferably from about 0.001 % to about 10%, more preferably from about 0.01% to about 1 % by weight of the composition.

The bar fabric cleaning composition embodiment of the present invention is illustrated by the following examples.

B. Additional Cleaning Compositions

In addition to the hard surface cleaning, dishwashing and fabric cleaning compositions discussed above, one or more enzyme variants of the present invention may be incorporated into a variety of other cleaning compositions where hydrolysis of an insoluble substrate is desired. Such additional cleaning compositions include but are not limited to, oral cleaning compositions, denture cleaning compositions, and contact lens cleaning compositions

1 Oral cleaning compositions

In another embodiment of the present invention, a pharmaceutically-acceptable amount of one or more enzyme variants of the present invention are included in compositions useful for removing proteinaceous stains from teeth or dentures As used herein, "oral cleaning compositions" refers to dentifrices, toothpastes, toothgels, toothpowders, mouthwashes, mouth sprays mouth gels, chewing gums, lozenges, sachets, tablets, biogels, prophylaxis pastes, dental treatment solutions, and the like Preferably, the oral cleaning compositions comprise from about 0 0001 % to about 20% of one or more enzyme variants of the present invention, more preferably from about 0 001 % to about 10%, more preferably still from about 0 01 % to about 5%, by weight of the composition, and a pharmaceutically-acceptable carrier As used herein, "pharmaceutically-acceptable" means that drugs, medicaments or inert ingredients which the term describes are suitable for use in contact with the tissues of humans and lower animals without undue toxicity, incompatibility, instability, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio

Typically, the pharmaceutically-acceptable oral cleaning carrier components of the oral cleaning components of the oral cleaning compositions will generally comprise from about 50% to about 99.99%, preferably from about 65% to about 99.99%, more preferably from about 65% to about 99%, by weight of the composition

The pharmaceutically-acceptable carrier components and optional components which may be included in the oral cleaning compositions of the present invention are well known to those skilled in the art A wide variety of composition types, carrier components and optional components useful in the oral cleaning compositions are disclosed in U.S Patent 5,096,700, Seibel, issued March 17, 1992, U.S. Patent 5,028,414, Sampathkumar, issued July 2, 1991 , and U.S. Patent 5,028,415, Benedict, Bush and Sunberg, issued July 2, 1991; all of which are incorporated herein by reference

The oral cleaning composition embodiment of the present invention is illustrated by the following examples

2. Denture cleaning compositions

In another embodiment of the present invention, denture cleaning compositions for cleaning dentures outside of the oral cavity comprise one or more enzyme variants of the present invention. Such denture cleaning compositions comprise an effective amount of one or more of the enzyme variants, preferably from about 0.0001 % to about 50% of one or more of the enzyme variants, more preferably from about 0.001 % to about 35%, more preferably still from about 0.01 % to about 20%, by weight of the composition, and a denture cleansing carrier. Various denture cleansing composition formats such as effervescent tablets and the like are well known in the art (see for example U.S. Patent 5,055,305, Young, incorporated herein by reference), and are generally appropriate for incorporation of one or more of the enzyme variants for removing proteinaceous stains from dentures.

The denture cleaning composition embodiment of the present invention is illustrated by the following examples.

3. Contact Lens Cleaning Compositions

In another embodiment of the present invention, contact lens cleaning compositions comprise one or more enzyme variants of the present invention Such contact lens cleaning compositions comprise an effective amount of one or more of the enzyme variants, preferably from about 0.01 % to about 50% of one or more of the enzyme variants, more preferably from about 0 01 % to about 20%, more preferably still from about 1 % to about 5%, by weight of the composition and a contact lens cleaning carrier Various contact lens cleaning composition formats such as tablets, liquids and the like are well known in the art (see for example U.S. Patent 4,863,627, Davies, Meaken and Rees, issued September 5, 1989, U.S. Patent Re 32,672, Huth, Lam and Kirai, reissued May 24, 1988, U.S. Patent 4,609 493, Schafer, issued September 2, 1986, U.S. Patent, 4,690,793, Ogunbiyi and Smith, issued September 1 , 1987, U.S. Patent 4,614,549, Ogunbiyi, Riedhammer and Smith, issued September 30, 1986, and U.S. Patent 4,285,738, Ogata, issued August 25, 1981 , each of which are incorporated herein by reference), and are generally appropriate for incorporation of one or more enzyme variants of the present invention for removing proteinaceous stains from contact lens

The contact lens cleaning composition embodiment of the present invention is illustrated by the following examples

In Examples 91-94, the Thermitase variants recited in Tables 2-36, among others, are substituted for Leu221 Gln, with substantially similar results

While particular embodiments of the subject invention have been described, it will be obvious to those skilled in the art that various changes and modifications of the subject invention can be made without departing from the spirit and scope of the invention. It is intended to cover, in the appended claims, all such modifications that are within the scope of the invention.

Missing upon filing

Claims

What is Claimed is:

1 A Thermitase variant having a modified amino acid sequence of

Thermitase wild-type amino acid sequence, the wild-type amino acid sequence comprising a first loop region, a second loop region, a third loop region, a fourth loop region, a fifth loop region and a sixth loop region, wherein the modified amino acid sequence comprises a substitution at one or more positions in one or more of the loop regions, wherein

A. when a substitution occurs in the first loop region, the substitution occurs at one or more of positions 66, 69, 70, 72 or 73, wherein

a. when a substitution occurs at position 66, the substituting amino acid is Asn;

b. when a substitution occurs at position 69, the substituting amino acid is Gln;

c. when a substitution occurs at position 70, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or Ser;

d. when a substitution occurs at position 72, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or Ser; and

e. when a substitution occurs at position 73, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or Ser;

B when a substitution occurs in the second loop region, the substitution occurs at one or more of positions 103, 104, 105 106, 108, 110, 112, 113 or 114, wherein

a. when a substitution occurs at position 103, the substituting amino acid is Ala, Asn, Asp, Cys, Gln, Glu, Gly, His, Met, Pro, Ser or Thr;

b. when a substitution occurs at position 104, the substituting amino acid is Ala, Asn, Asp, Cys, Gln, Gly, His, Ile, Met, Pro or Ser;

c. when a substitution occurs at position 105, the substituting amino acid is Glu;

d. when a substitution occurs at position 106, the substituting amino acid is Gln; e. when a substitution occurs at position 108, the substituting amino acid is Asn, Gln, Pro or Ser;

f. when a substitution occurs at position 110, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

g. when a substitution occurs at position 112, the substituting amino acid is Asn, Asp, Cys, Gln, Glu, His, Ile, Met, Phe, Pro, Thr or Tyr;

h. when a substitution occurs at position 113, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser; and

i. when a substitution occurs at position 114, the substituting amino acid is Asn, Asp, Gln, Glu, Gly, His,

Pro, Ser or Thr;

C. when a substitution occurs in the third loop region, the substitution occurs at one or more of positions 134, 135, 136, 137, 138, 139 or 141 , wherein

a. when a substitution occurs at position 134, the substituting amino acid is Ala, Asn, Cys, Gln, Gly, His,

Met, Pro, Ser, Thr or Val,

b. when a substitution occurs at position 135, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser,

c. when a substitution occurs at position 136, the substituting amino acid is Pro,

d. when a substitution occurs at position 137, the substituting amino acid is Asn, Asp, Gln, Glu or Ser; e. when a substitution occurs at position 138, the substituting amino acid is Ala, Asn, Asp, Cys, Gln, Glu,

Gly, His, Met, Pro, Ser or Thr;

f. when a substitution occurs at position 139, the substituting amino acid is Asn, Gln, Pro or Ser; and g. when a substitution occurs at position 141 , the substituting amino acid is Asp or Glu,

D . when a substitution occurs in the fourth loop region, the substitution occurs at one or more of positions 167, 169, or 171 , wherein a. when a substitution occurs at position 167, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

b. when a substitution occurs at position 169, the substituting amino acid is Asn, Asp, Gln, Glu, Gly or

Ser; and

c. when a substitution occurs at position 171 , the substituting amino acid is His, Ile, Leu, Met or Pro, E. when a substitution occurs in the fifth loop region, the substitution occurs at one or more of position 193, wherein a. when a substitution occurs at position 193, the substituting amino acid is Asn, Cys, Gln, His, Ile, Met,

Thr or Tyr;

F. when a substitution occurs in the sixth loop region, the substitution occurs at one or more of positions 204, 205 206, 207, 208, 209, 210, 211 , 212, 213, 214, 215, 216, 217, 220, 221 , 223 or 224, wherein

a. when a substitution occurs at position 204, the substituting amino acid is Asn, Asp, Gln, Glu, Gly, His,

Pro, Ser or Thr;

b. when a substitution occurs at position 205, the substituting amino acid is Asn, Asp, Gln, Glu, Gly or

Ser;

c. when a substitution occurs at position 206, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

d. when a substitution occurs at position 207, the substituting amino acid is Asp or Glu,

e. when a substitution occurs at position 208, the substituting amino acid is Asp or Glu,

f. when a substitution occurs at position 209, the substituting amino acid is Ala, Asn, Asp, Cys, Gln, Glu,

Gly, His, Leu, Met, Pro, Ser; Thr or Val,

g. when a substitution occurs at position 210, the substituting amino acid is Asp, His, Ile, Leu, Met or Pro, h . when a substitution occurs at position 211 , the substituting amino acid is Asp or Glu, i. when a substitution occurs at position 212, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

j. when a substitution occurs at position 213, the substituting amino acid is Asp, Glu, His, Ile, Leu, Met,

Phe, Pro or Val,

k. when a substitution occurs at position 214, the substituting amino acid is Asn, Gln, Gly, or Ser;

I. when a substitution occurs at position 215, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

m. when a substitution occurs at position 216, the substituting amino acid is Asp or Glu, n. when a substitution occurs at position 217, the substituting amino acid is Asp, Glu or Pro,

o. when a substitution occurs at position 220, the substituting amino acid is Asp or Glu, p. when a substitution occurs at position 221 , the substituting amino acid is Ala, Asn, Asp, Cys, Gln, Glu,

Gly, His, Ile, Met, Pro, Ser; Thr or Val, q. when a substitution occurs at position 222, the substituting amino acid is Asp or Glu, r. when a substitution occurs at position 223, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser; and

s. when a substitution occurs at position 224, the substituting amino acid is Asn, Asp, Gln, Glu, Pro or

Ser;

whereby the Thermitase variant has decreased adsorption to, and increased hydrolysis of, an insoluble substrate as compared to wild-type Thermitase.

2 The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the first loop region.

3 The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the second loop region .

4. The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the third loop region.

5. The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the fourth loop region.

6. The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the fifth loop region.

7. The Thermitase variant of Claim 1 , wherein one or more substitutions occur in the sixth loop region.

8. A cleaning composition selected from the group consisting of a hard surface cleaning composition, a dishwashing composition, an oral cleaning composition, a denture cleansing composition, a contact lens cleaning composition and a fabric cleaning composition, characterized in that the cleaning composition comprises the Thermitase variant of any of Claims 1-7 and a cleaning composition carrier; preferably the cleaning composition is a hard surface cleaning composition or the cleaning composition is a fabric cleaning composition; preferably the composition comprises at least about 5% surfactant and at least about 5% builder; by weight of the composition; preferably the composition further comprises cleaning composition materials selected from the group consisting of solvents, buffers, enzymes, soil release agents, clay soil removal agents, dispersing agents, brighteners, suds suppressors, fabric softeners, suds boosters, enzyme stabilizers, bleaching agents, dyes, perfumes, and mixtures thereof.

9. A DNA sequence encoding the Thermitase variant of any of Claims 1-7.