Microbial trypsin mutants having chymotrypsin activity and nucleic acids encoding same

1. A variant of a trypsin polypeptide, wherein the variant comprises the specific combination of modifications as follows:

(a) substitutions at positions corresponding to positions 144, 193, 198, 201, 218, 223, 227, 228, 229, 230, and 231 of amino acids 25 to 248 of SEQ ID NO: 2;

(b) deletions at positions corresponding to positions 192, 197, and 226 of amino acids 25 to 248 of SEQ ID NO: 2; and

(c) an insertion between positions corresponding to positions 224 and 225 of amino acids 25 to 248 of SEQ ID NO: 2; and

wherein, the variant has chymotrypsin activity and

(i) has at least 90% identity to amino acids 25 to 248 of SEQ ID NO: 2; or

(ii) is encoded by a nucleotide sequence which hybridize under at least medium-high stringency conditions with nucleotides 202 to 801 of SEQ ID NO: 1 or the complete complementary strand thereto, wherein medium-high stringency conditions are defined as prehybridization and hybridization at 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmon sperm DNA, and 35% formamide followed by washing three times each for 15 minutes using 2×SSC, 0.2% SDS at 60° C.

2. The variant of claim 1 , wherein the variant is encoded by the nucleotide sequence contained in pEJG66.1XLGOLD, which is contained in E coli NRRL B-30627.

3. The variant of claim 1 , wherein the variant is in a form of a precursor comprising amino acids 1 to 24 of SEQ ID NO: 2 as a prepro region, or a portion thereof, linked in translation reading frame with the amino terminus of the variant.

4. A laundry detergent composition comprising the variant of claim 1 and a surfactant.

5. The variant of claim 1 , which comprises the substitutions V144T+S193A+D198S+Q201M+A218I+N223S+R227S+P228T+N229S+Y230T+S231P, the deletions V192*+K197*+A226*, and the insertion G224GT of amino acids 25 to 248 of SEQ ID NO: 2.

6. The variant of claim 1 , wherein the trypsin polypeptide has an amino acid sequence which has at least 90% identity to amino acids 25 to 248 of SEQ ID NO. 2.

7. The variant of claim 6 , wherein the trypsin polypeptide has an amino acid sequence which has at least 95% identity to amino acids 25 to 248 of SEQ ID NO: 2.

8. The variant of claim 1 , wherein the trypsin polypeptide has the amino acid sequence of amino acids 25 to 248 of SEQ ID NO: 2.

9. The variant of claim 1 , wherein the trypsin polypeptide is encoded by a nucleotide sequence which hybridizes under medium-high stringency conditions with the complete nucleotide sequence of nucleotides 202 to 801 of SEQ ID NO: 1, wherein medium-high stringency conditions are defined as prehybridization and hybridization at 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmon sperm DNA, and 35% formamide followed by washing three times each for 15 minutes using 2×SSC, 0.2% SDS at 60° C.

10. The variant of claim 9 , wherein the trypsin polypeptide is encoded by a nucleotide sequence which hybridizes under high stringency conditions with nucleotides 202 to 801 of SEQ ID NO: 1 or the nucleotide sequence of nucleotides 202 to 801 of SEQ ID NO 1, wherein high stringency conditions are defined as prehybridization and hybridization at 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmon sperm DNA, and 50% formamide followed by washing three times each for 15 minutes using 2×SSC, 0.2% SDS at 65° C.

11. The variant of claim 1 , wherein the trypsin polypeptide is a wild-type trypsin polypeptide.

12. The variant of claim 7 , wherein the trypsin polypeptide has an amino acid sequence which has at least 97% identity to amino acids 25 to 248 of SEQ ID NO: 2.

13. The variant of claim 1 , which comprises amino acids 25 to 246 of SEQ ID NO: 4.

14. The variant of claim 1 , wherein the variant has at least 95% identity to amino acids 25 to 248 of SEQ ID NO: 2.

15. The variant of claim 14 , wherein the variant has at least 97% identity to amino acids 25 to 248 of SEQ ID NO: 2.