Characterization of an excellent anti-Prelog short-chain dehydrogenase/reductase EbSDR8 from Empedobacter brevis ZJUY-1401

Empedobacter brevis ZJUY-1401 is capable of producing anti-Prelog alcohols with excellent stereoselectivity. The gene encoding a short-chain dehydrogenase/reductase from E. brevis ZJUY-1401 (EbSDR8) was cloned and heterologously expressed in Escherichia coil, and the purified recombinant protein was characterized. The subunit of EbSDR8 is composed of 250 amino acids with a calculated molecular mass of 26.4 kDa. Important properties regarding the application of EbSDR8 include utilization of cheaper coenzyme, the excellent catalytic performance over a broad pH range from 7.0 to 10.5, and temperature optimum of 35 degrees C. The enzyme showed moderate thermostability, with half-lives of 4.4 h at 35 degrees C and 3.1 h at 45 degrees C, respectively. In the presence of isopropanol as a cosubstrate, the whole-cell of recombinant E. coil expressing EbSDR8 could efficiently catalyze the asymmetric reduction without addition of any NADH into the reaction system. EbSDR8 displayed good activity and excellent stereoselectivity toward a spectrum of acetophenone derivatives, providing anti-Prelog alcohols with >99% ee for the majority of the substrates. These results suggest that EbSDR8 is a powerful chiral tool for the production of anti-Prelog alcohols. (C) 2015 Elsevier B.V. All rights reserved.