Patent ID: 6969600

Claim:
A purified carbonyl reductase having the following physicochemical properties: reduces 4-haloacetoacetate ester to produce (S)-4-halo-3-hydroxybutyrate ester using reduced Î²-nicotinamide ademne dinucleotide as an electron donor; has high reductase activity for 4-chloroacetoacetate ester but does not substantially dehydrogenate any optical isomers of 4-halo-3-hydroxybutyrate ester; shows higher enzymatic activity when used with reduced Î²-nicotinamide adenine dinucleotide as an electron donor than when used with reduced Î²-nicotinamide adenine dinucleotide phosphate; has an optimal pH of 5.0 to 6.0; does not substantially dehydrogenate isopropanol and does not reduce acetoacetate; and has a molecular weight of about 32,000 daltons when determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis; wherein the carbonyl reductase is a Kluyveromyces aestuarii carbonyl reductase.