Screening, Molecular Cloning, and Biochemical Characterization of an Alcohol Dehydrogenase from Pichia pastoris Useful for the Kinetic Resolution of a Racemic β-Hydroxy-β-trifluoromethyl Ketone.

The stereoselective synthesis of chiral 1,3-diols with the aid of biocatalysts is an attractive tool in organic chemistry. Besides the reduction of diketones, an alternative approach consists of the stereoselective reduction of β-hydroxy ketones (aldols). Thus, we screened for an alcohol dehydrogenase (ADH) that would selectively reduce a β-hydroxy-β-trifluoromethyl ketone.

Development of a growth-dependent selection system for identification of L-threonine aldolases.

Threonine aldolases (TAs) are useful enzymes for the synthesis of β-hydroxy-α-amino acids due to their capability to catalyze asymmetric aldol reactions. Starting from two prochiral compounds, an aldehyde and glycine, two chiral stereocenters were formed in a single step via C-C bond formation. Owing to poor diastereoselectivity and low activity, the enzymatic synthesis of β-hydroxy-α-amino acids by TAs is still a challenge.