PROCESSES USING AMINO ACID DEHYDROGENASES AND KETOREDUCTASE-BASED COFACTOR REGENERATING SYSTEM

摘要

The present disclosure relates to the use of an amino acid dehydrogenase in combination with a cofactor regenerating system comprising a ketoreductase. In particular embodiments, the process can be used to prepare L-tert-leucine using a leucine dehydrogenase.

主权项

1. A process for converting a compound of formula I which is a substrate for an amino acid dehydrogenase to a chiral amino acid of formula IIa:comprising contacting the compound of formula I with a reaction medium comprising a leucine dehydrogenase, an ammonium ion donor selected from ammonia or an ammonium salt, a cofactor selected from NAD+/NADH or NADP+/NADPH, and a cofactor regenerating system comprising an engineered ketoreductase having at least 90% sequence identity to SEQ ID NO:18, which has less than 5% of the activity of a leucine dehydrogenase, with compound of formula I and a lower secondary alcohol, under conditions where the compound of formula I is converted to the chiral amino acid of formula IIa and the lower secondary alcohol is converted to a ketone.