文献类型：期刊文献

英文题名：Purification and partial characterization of recombinant Cu, Zn containing superoxide dismutase of Cordyceps militaris in E. coli

作者：Wang, Zunsheng[1,2]; He, Zhuojing[1]; Shen, Qiong[1]; Gu, Yuxiang[1]; Li, Suxia[1]; Yuan, Qinsheng[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; [2] Department of Biology, Shenyang Normal University, Shenyang 110034, China

年份：2005

卷号：826

期号：1-2

起止页码：114

外文期刊名：Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences

收录：EI(收录号：2005429426124)

语种：英文

外文关键词：Amino acids - Characterization - Copper oxides - DNA - Escherichia coli - pH - Purification - Zinc oxide

摘要：The cDNA of Cu, Zn containing superoxide dismutase from the Cordyceps militaris SH (cm-SOD) was overexpressed in Escherichia coli BL 21 (DE3) using the pET-21a expression vector. The recombinant cell overexpressed the protein corresponding to 35 ± 3% of total bacterial protein in cytosol. The purification was performed through three steps: DEAE-FF, CM-52, and G-100. After this purification procedure, a specific activity of 27272.7 U/mg of protein was reached, corresponding to 6.1-fold purification with a yield of 85.0%. The purity was homogeneous by SDS-PAGE analysis and 94.2 ± 1.0% by CZE analysis. A subunit molecular mass of the recombinant enzyme was 15704 Da with a Cu and Zn element. In addition, the dimeric and polymeric structures were observed on MALDI-TOF-MS. Isoelectric point value of 7.0 was obtained for the recombinant enzyme that was sensitive to H2O2 and KCN. The recombinant enzyme remained 80 ± 2% residual activity at pH 7.8, at 50°C for 4 h incubation. The properties: N-terminal amino acid sequence (the first 12 amino acid residues), pI, subunit molecular mass, thermo-stability of the purified recombinant SOD are similar to that of the native Cu, Zn-SOD from C. militaris (N-cm-SOD). ? 2005 Elsevier B.V. All rights reserved.