文献类型：期刊文献

英文题名：Characterization of a Putative Stereoselective Oxidoreductase from Gluconobacter oxydans and Its Application in Producing Ethyl (R)-4-Chloro-3-Hydroxybutanoate Ester

作者：Liu, Xu[1];Chen, Rong[1,2];Yang, Zhongwei[1];Wang, Jiale[1];Lin, Jinping[1];Wei, Dongzhi[1]

机构：[1]E China Univ Sci & Technol, New World Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Hangzhou Normal Univ, Ctr Biomed & Hlth, Hangzhou 310012, Zhejiang, Peoples R China

年份：2014

卷号：56

期号：4

起止页码：285

外文期刊名：MOLECULAR BIOTECHNOLOGY

收录：;EI(收录号：20141417530406);WOS:【SCI-EXPANDED(收录号:WOS:000332972300001)】；

基金：This work was financially supported by the National Key Basic Research. Development Program of China ("973'' Program, No. 2012CB721003), the Natural Science Foundation of China (No. 21002029/B020706 and 21276084/B060804) and National Major Science and Technology Projects of China (No. 2012ZX09304009).

语种：英文

外文关键词：Gluconobacter oxydans; Oxidoreductase; Ethyl (R)-4-chloro-3-hydroxybutanoate ester

摘要：A gene encoding an NADH-dependent short-chain dehydrogenase/reductase (gox2036) from Gluconobacter oxydans 621H was cloned and heterogeneously expressed in Escherichia coli. The protein (Gox2036) was purified to homogeneity and biochemically characterized. Gox2036 was a homotetramer with a subunit size of approximately 28 kDa. Gox2036 had a strict requirement for NAD(+)/NADH as the cofactor. Gox2036 displayed preference for oxidation of secondary alcohols and 2,3-diols as well as for reduction of alpha-diketones, hydroxy ketones, alpha-ketoesters, and beta-ketoesters. However, Gox2036 was poorly active on 1,2-diols and acetoin and showed no activity on primary alcohols, polyols, and aldehydes. The optimum pH values for the oxidation and reduction reactions were 9 and 6, respectively. Gox2036 was highly selective in the reduction of various beta-ketones and beta-ketoesters. Among the substrates tested, ethyl 4-chloro acetoacetate was reduced to ethyl (R)-4-chloro-3-hydroxybutanoate ester with an excellent conversion yield of 96.9 % and optical purity of > 99 % e.e. using an efficient in situ NADH-recycling system involving glucose and a glucose dehydrogenase from Bacillus subtilis (BsGDH).