文献类型：期刊文献

英文题名：A novel nitrilase from Rhodobacter sphaeroides LHS-305: cloning, heterologous expression and biochemical characterization

作者：Wang, Hualei[1];Li, Guinan[1];Li, Mingyang[1];Wei, Dongzhi[1];Wang, Xuedong[1]

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

年份：2014

卷号：30

期号：1

起止页码：245

外文期刊名：WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

收录：;EI(收录号：20140217188895);WOS:【SCI-EXPANDED(收录号:WOS:000329248200025)】；

语种：英文

外文关键词：Nitrilase; Rhodobacter sphaeroides; 3-Cyanopyridine; Substrate specificity; Regioselectivity

摘要：In this study, a novel nitrilase gene from Rhodobacter sphaeroides was cloned and overexpressed in Escherichia coli. The open reading frame of the nitrilase gene includes 969 base pairs, which encodes a putative polypeptide of 322 amino acid residues. The molecular weight of the purified native nitrilase was about 560 kDa determined by size exclusion chromatography. This nitrilase showed one single band on SDS-PAGE with a molecular weight of 40 kDa. This suggested that the native nitrilase consisted of 14 subunits with identical size. The optimal pH and temperature of the purified enzyme were 7.0 and 40 A degrees C, respectively. The kinetic parameters V (max) and K (m) toward 3-cyanopyridine were 77.5 mu mol min(-1) mg(-1) and 73.1 mmol/l, respectively. The enzyme can easily convert aliphatic nitrile and aromatic nitriles to their corresponding acids. Furthermore, this enzyme demonstrated regioselectivity in hydrolysis of aliphatic dinitriles. This specific characteristic makes this nitrilase have a great potential for commercial production of various cyanocarboxylic acids by hydrolyzing readily available dinitriles.