Laboratory Evolved Biocatalysts for Stereoselective Syntheses of Substituted Benzaldehyde Cyanohydrins

Abstract

Random mutagenesis and recombination of PaHNL5 was carried out in Pichia pastoris by employment of an overlap extension PCR-based strategy. New fast and stereoselective enzyme variants were obtained, and these led to improved turnover rates with the nonnatural substrate 2-chlorobenzaldehyde. A new catalyst combining all favorable mutations was generated, and even very small amounts of this variant enabled complete conversion of 2-chlorobenzaldehyde into the (R)-hydroxynitrile with >99 % ee in only 4 h. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2268/2008/z700514_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.