Development of a Thioredoxin‐Based Cofactor Regeneration System for NADPH‐Dependent Oxidoreductases
Ningning Zhang, B Müller, Tanja Ørtoft Kirkeby, Selin Kara, Christoph Loderer
Abstract
Abstract Nicotinamide cofactor‐dependent oxidoreductases have become a valuable tool for the synthesis of high value chiral compounds. The feasibility of biocatalytic processes involving these enzymes stands and falls with the efficiency of the regeneration of cofactors. In this study, we describe a novel NADPH regeneration method based on the natural thioredoxin electron delivery system. Thioredoxin 1 (Trx1) and thioredoxin reductase (TR) from Thermus thermophilus were characterized for the dithiol‐dependent reduction of NADP + , revealing good catalytic activities and a particularly remarkable thermostability. The TR/Trx1 system was then coupled with two representative NADPH‐dependent oxidoreductases, alcohol dehydrogenase and cyclohexanone monooxygenase. Reaction conditions for both systems were optimized for reaction yield and selectivity. The results demonstrate the feasibility of the TR/Trx1‐system for its application as NADPH regeneration system.