Ruan Li-Tao, Zheng Ren-Chao, Zheng Yu-Guo, Shen Yin-Chu
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
Int J Biol Macromol. 2016 May;86:893-900. doi: 10.1016/j.ijbiomac.2016.02.020. Epub 2016 Feb 8.
A R-stereospecific amidase was purified from Brevibacterium epidermidis ZJB-07021 and characterized in detail. The amidase was purified to homogeneity by three chromatographic steps for up to 328.9-fold with specific activity of 31.9 U mg(-1). The enzyme was a homodimer with a molecular mass of 94 kDa. It exhibited maximum activity at 40 °C and pH 7.5. The enzyme was strongly inactivated by serine protease inhibitor PMSF. The values of Km and Vmax for racemic 2,2-dimethylcyclopropane carboxamide (DMCPCA) were 4.58 mM and 35.03 μmol min(-1) mg(-1) protein, respectively. The amidase showed a broad substrate spectrum toward aliphatic, aromatic and heterocyclic amides, but could hardly hydrolyze the bulky side-chain-containing amides. Furthermore, kinetic resolution of racemic DMCPCA by the amidase afforded S-DMCPCA in 46.3% yield and 99% ee with an average E-value of 67. These unique properties of the amidase imply that it is a promising biocatalyst for the production of chiral amides and carboxylic acids.
