Enzymatic Preparation of Optically Active Carboxylic Acids and Their Applications

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.