earticle

영어

Enzyme flexibility is thought to be related to enzyme activity conceptually. But there has been no attempt to enhance enzyme activity by modulation of enzyme flexibility. In this study, enzyme mutations of Candida antarctica lipase B were performed with the aim of activity enhancement. In the analysis using spring model developed in our laboratory and the molecular dynamics simulation in the organic solvents, the forced or twisted residues and residues showing solvent-dependent flexibility change were mostly located at the active site surroundings. Accordingly, the target sites were selected the edges of helices surrounding active site. The flexible amino acids, D and E, were preferentially chosen as the alternatives. In the E.coli expression system, three mutations among seven target sites showed activity enhancement. And two mutants among three activity enhanced mutants were obtained in the Pichia pastoris expression system and they all showed enhanced activity.