1997 年 55 巻 7 号 p. 642-650
The application of enzymes or microorganisms to an organic synthesis is one of the most useful and practical methods for the preparation of optically active compounds. We have developed a novel process for enzymatic preparation of D- (-) -β-acetylthioisobutyric acid. A newly isolated strain, Pseudomonas putida MR-2068, produced an attractive esterase. A gene for the esterase was cloned and expressed in the Escherichia coli cells. The result of a sequence analysis and some characteristics of the purified enzyme are described. This esterase also catalyzed regio- and enantioselective hydrolysis of α-substituted carboxylic acid esters. Considering the results of enzymatic reactions, the active site model of enzyme is tentatively proposed.