文献类型：期刊文献

英文题名：Stereoselective synthesis of L-tert-leucine by a newly cloned leucine dehydrogenase from Exiguobacterium sibiricum

作者：Li, Jing[1];Pan, Jiang[1];Zhang, Jie[1];Xu, Jian-He[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biocatalysis & Synthet Biotechnol, Shanghai 200237, Peoples R China

年份：2014

卷号：105

起止页码：11

外文期刊名：JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC

收录：;EI(收录号：20141717618037);WOS:【SCI-EXPANDED(收录号:WOS:000337551900003)】；

基金：Thanks to financial supports from National Natural Science Foundation of China (Nos. 31200050 and 21276082), and Ministry of Science and Technology of the People's Republic of China (Nos. 2011AA02A210 and 2011CB710800).

语种：英文

外文关键词：Leucine dehydrogenase; Exiguobacterium sibiricum; Reductive amination; Dual enzyme co-expression; L-tert-Leucine

摘要：A leucine dehydrogenase from Exiguobacterium sibiricum (EsLeuDH) was discovered by genome mining approach. The EsLeuDH was over expressed in Escherichia coli BL21, purified to homogeneity and characterized. This enzyme showed good thermostability with a half-life of 3.1 h at 60 C. Furthermore, EsLeuDH has a broad spectrum of substrate specificity, showing activities toward many aliphatic a-keto acids and L-amino acids, in addition to some aryl alpha-keto acids and aryl a-amino acids, such as alpha-oxobenzeneacetic and L-phenylglycine. The EsLeuDH was successfully coexpressed with Bacillus megaterium glucose dehydrogenase (BmGDH) in Escherichia coli BL21 for the production of L-tert-leucine. By using the coexpressed whole cells, a decagram preparation of L-tert-leucine was performed at a substrate concentration of 0.6 M (78.1 g L-1) in 1 L scale with 99% conversion after 5.5 h, resulting in 80.1% yield and > 99% ee (enantiomeric excess). (C) 2014 Published by Elsevier B.V.