Purification and Some Properties of Carboxylesterase from Arthrobacter globiformis; Stereoselective Hydrolysis of Ethyl Chrysanthemate

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An esterase with excellent stereoselectivity for (+)-trans-ethyl chrysanthemate was purified to homogeneity from Arthrobacter globiformis SC-6-98-28. The purified enzyme hydrolyzed a mixture of ethyl chrysanthemate isomers stereoselectively to produce (+)-trans-acid with 100% stereoisomeric purity. The apparent molecular weight of the purified enzyme was 43, 000 on SDS-polyacrylamide gel electrophoresis, and 94, 000 on gel filtration chromatography. The optimum conditions for the ester hydrolysis were pH 10.0 at 45°C. The purified esterase hydrolyzed short-chain fatty acid esters, but did not have detectable activity on long-chain water-insoluble fatty acid esters. The enzyme activity was inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride.