title: Purification and characterization of R-stereospecific amidase from Brevibacterium epidermidis ZJB-07021.
abstract: 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.
authors: 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.
authors: Li-Tao
authors: LT
authors: Ruan
authors: 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.
authors: Ren-Chao
authors: RC
authors: Zheng
authors: 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. Electronic address: zhengyg88320630@163.com.
authors: Yu-Guo
authors: YG
authors: Zheng
authors: 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.
authors: Yin-Chu
authors: YC
authors: Shen
mesh_terms: D000581:Amidohydrolases / Q000302:isolation & purification* / Q000378:metabolism*; D001951:Brevibacterium / Q000201:enzymology*; D003521:Cyclopropanes / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: C522704:2,2-dimethylcyclopropanecarboxamide; D003521:Cyclopropanes; D008670:Metals; D000581:Amidohydrolases; C019665:amidase
keywords: 2,2-Dimethylcyclopropane carboxamide; Amidase; Brevibacterium epidermidis; Kinetic resolution