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Shijiazhuang, China

Wang L.,Tianjin University of Science and Technology | Wang L.,CAS Tianjin Institute of Industrial Biotechnology | Yuan J.,CAS Tianjin Institute of Industrial Biotechnology | Yao P.,CAS Tianjin Institute of Industrial Biotechnology | And 7 more authors.
Shengwu Gongcheng Xuebao/Chinese Journal of Biotechnology | Year: 2015

Halohydrin dehalogenase is of great significance for biodegradation of the chlorinated pollutants, and also serves as an important biocatalyst in the synthesis of chiral pharmaceutical intermediates. A putative halohydrin dehalogenase (HheTM) gene from Tistrella mobilis KA081020-065 was cloned and over-expressed in Escherichia coli BL21 (DE3). The recombinant enzyme was purified by Ni-NTA column and characterized. Gel filtration and SDS-PAGE analysis showed that the native form of HheTM was a tetramer. It exhibited the highest activity at 50℃. The nature and pH of the buffer had a great effect on its activity. The enzyme maintained high stability under the alkaline conditions and below 30℃. HheTM catalyzed the transformation of ethyl(S)-4-chloro-3-hydroxybutyrate in the presence of cyanide, to give ethyl(R)-4-cyano-3-hydroxybutyrate, a key intermediate for the synthesis of atorvastatin. © 2015 Chin J Biotech, All rights reserved.


Yao P.,CAS Tianjin Institute of Industrial Biotechnology | Wang L.,CAS Tianjin Institute of Industrial Biotechnology | Wang L.,Tianjin University of Science and Technology | Yuan J.,CAS Tianjin Institute of Industrial Biotechnology | And 7 more authors.
ChemCatChem | Year: 2015

An effective one-pot bienzymatic synthesis of ethyl (R)-3-hydroxyglutarate (EHG) from ethyl (S)-4-chloro-3-hydroxybutyrate (ECHB) was achieved by using recombinant Escherichia coli cells expressing separately or co-expressing a mutant halohydrin dehalogenase gene from Agrobacterium radiobacter AD1 and a nitrilase gene from Arabidopsis thaliana. The activity of nitrilase was inhibited by high concentration of ECHB and NaCN. Consequently, the one-pot one-step process was implemented by fed-batch of ECHB and NaCN with high accumulative product concentration (up to 0.9 mol L-1). The biotransformation of ECHB to EHG was successfully achieved at 1.2 mol L-1 substrate concentration by a one-pot two-step process. As such, this one-pot bienzymatic transformation should be useful in synthesizing these important optical pure β-hydroxycarboxylic acids. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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