Mutant-type lipases and applications thereof
First Claim
1. A purified mutant lipase comprising a serine-histidine-aspartic acid catalytic triad;
- wherein the amino acid residue following said serine residue of said triad is replaced with an alanine;
triad wherein said mutant lipase hydrolyzes fatty acid esters or esterifies fatty acids; and
wherein the wild-type lipase of said mutant lipase is isolated from a gram positive or gram negative bacterium or fungus.
0 Assignments
0 Petitions
Accused Products
Abstract
The present invention provides mutant-type lipases which demonstrate superior lipolytic and esterific activities. The mutant-type lipases are characterized by an amino acid alteration at the residue immediately followed either the serine residue or the histidine residue or both residues of the Ser-His-Asp catalytic triad. The Ser-His-Asp catalytic triad is known to be the three residues, although occur far apart in the amino acid sequence of a lipase, that contribute to the hydrolytic activity in the active site of the lipase. The amino acid residue that follows the serine residue of the Ser-His-Asp catalytic triad is alanine. The amino acid residue that follows the histidine residue of the Ser-His-Asp catalytic triad is isoleucine. The wild-type lipase is preferably originated from Staphylococcus, particularly Staphylococcus epidermindis. The present invention also relates to a method for preparing the mutant-type lipases by site-directed mutagenesis using PCR and a method for utilizing the mutant-type lipase to catalyze synthesis of flavor esters to be used in food industry.
26 Citations
28 Claims
-
1. A purified mutant lipase comprising a serine-histidine-aspartic acid catalytic triad;
- wherein the amino acid residue following said serine residue of said triad is replaced with an alanine;
triad wherein said mutant lipase hydrolyzes fatty acid esters or esterifies fatty acids; and
wherein the wild-type lipase of said mutant lipase is isolated from a gram positive or gram negative bacterium or fungus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- wherein the amino acid residue following said serine residue of said triad is replaced with an alanine;
-
27. A purified mutant lipase comprising a serine-histidine-aspartic acid catalytic triad;
- wherein the amino acid residue following said histindine residue of said triad is replaced with an isoleucine, wherein said mutant lipase hydrolyzes fatty acid esters or esterifies fatty acids; and
wherein the wild-type lipase of said mutant lipase is isolated from staphylococcus.
- wherein the amino acid residue following said histindine residue of said triad is replaced with an isoleucine, wherein said mutant lipase hydrolyzes fatty acid esters or esterifies fatty acids; and
-
28. A purified mutant lipase having the amino acid sequence of SEQ ID NO:
- 17.
Specification