A novel NADPH-dependent aldehyde reductase, catalyzing asymmetric reduction of ß-keto acid esters, fromSporobolomyces salmonicolor: purification and characterization

Abstract

NADPH-dependent aldehyde reductase (EC 1.1.1.2) was purified 23-fold with an overall yield of 11% from Sporobolomyces salmonicolor AKU 4429, in 4 steps and, by adding ammonium sulfate, the enzyme was crystallized. The enzyme has a strict requirement for NADPH and irrversibly reduces a number of aldehydes, such as p-nitrobenzaldehyde, pyridine-3-aldehyde and d-glyceraldehyde. Furthermore, it was found that the enzyme catalyses stereospecific reduction of 4-halo-3-oxobutanoate esters to the corresponding (R)-4-halo-3-hydroxybutanoate esters, which are promising chiral compounds for the chemical synthesis of l-carnitine.