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Directed evolution of an enantioselective lipase with broad substrate scope for hydrolysis of alpha-substituted esters.

Research paper by Karin K Engström, Jonas J Nyhlén, Anders G AG Sandström, Jan-E JE Bäckvall

Indexed on: 11 May '10Published on: 11 May '10Published in: Journal of the American Chemical Society



Abstract

A variant of Candida antarctica lipase A (CalA) was developed for the hydrolysis of alpha-substituted p-nitrophenyl esters by directed evolution. The E values of this variant for 7 different esters was 45-276, which is a large improvement compared to 2-20 for the wild type. The broad substrate scope of this enzyme variant is of synthetic use, and hydrolysis of the tested substrates proceeded with an enantiomeric excess between 95-99%. A 30-fold increase in activity was also observed for most substrates. The developed enzyme variant shows (R)-selectivity, which is reversed compared to the wild type that is (S)-selective for most substrates.