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] Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, 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：EI(收录号：20122415118205)

语种：英文

外文关键词：Data mining - Hydrolysis - Lanthanum compounds - Enantioselectivity

摘要：(R)-o-Chloromandelic acid is the key precursor for the synthesis of Clopidogrel?, a best-selling cardiovascular drug. Although nitrilases are often used as an efficient tool in the production of α-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 Vmax and K m of LaN were 2.53 μmol 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. ? 2012 Springer-Verlag.