文献类型：期刊文献

英文题名：Efficient production of (R)-o-chloromandelic acid by deracemization of o-chloromandelonitrile with a new nitrilase mined from Labrenzia aggregata

作者：Zhang, Chen-Sheng[1];Zhang, Zhi-Jun[1];Li, Chun-Xiu[1];Yu, Hui-Lei[1];Zheng, Gao-Wei[1];Xu, Jian-He[1]

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

年份：2012

卷号：95

期号：1

起止页码：91

外文期刊名：APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000304868000007)】；

基金：This work was financially supported by National Natural Science Foundation of China (grant number 20902023), Ministry of Science and Technology, People's Republic of China (numbers 2011CB710800, 2011AA02A210), Shanghai Committee of Science and Technology (grant number 11431921600), Innovation Program of Shanghai Municipal Education Commission (grant number 11CXY24), and China National Special Fund for State Key Laboratory of Bioreactor Engineering (grant number 2060204).

语种：英文

外文关键词：Nitrilase; Labrenzia aggregate; Enantioselective hydrolysis; (R)-o-Chloromandelic acid; Biphasic system

摘要：(R)-o-Chloromandelic acid is the key precursor for the synthesis of ClopidogrelA (R), a best-selling cardiovascular drug. Although nitrilases are often used as an efficient tool in the production of alpha-hydroxy acids, there is no practical nitrilase specifically developed for (R)-o-chloromandelic acid. In this work, a new nitrilase from Labrenzia aggregata (LaN) was discovered for the first time by genomic data mining, which hydrolyzed o-chloromandelonitrile with high enantioselectivity, yielding (R)-o-chloromandelic acid in 96.5% ee. The LaN was overexpressed in Escherichia coli BL21 (DE3), purified, and its catalytic properties were studied. When o-chloromandelonitrile was used as the substrate, the V (max) and K (m) of LaN were 2.53 mu mol min(-1) mg(-1) protein and 0.39 mM, respectively, indicating its high catalytic efficiency. In addition, a study of substrate spectrum showed that LaN prefers to hydrolyze arylacetonitriles. To relieve the substrate inhibition and to improve the productivity of LaN, a biphasic system of toluene-water (1:9, v/v) was adopted, in which o-chloromandelonitrile of 300 mM (apparent concentration, based on total volume) could be transformed by LaN in 8 h, giving an isolated yield of 94.5%. The development of LaN makes it possible to produce (R)-o-chloromandelic acid by deracemizing o-chloromandelonitrile with good ee value and high substrate concentration.