The role of cupric in maintaining the structure of CopC

作     者：ZHENG XiaoYan PANG ErGuo LI HuiQin ZHAO YaQin YANG BinShengt 

作者机构：Institute of Molecular Science Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education ShanxiUniversity Taiyuan 030006 China 

出 版 物：《Chinese Science Bulletin》 (CHINESE SCIENCE BULLETIN)

年 卷 期：2007年第52卷第6期

页      面：743-747页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Supported by the National Natural Science Foundation of China (Grant No.20371031) the Natural Science Foundation of Shanxi Province (Grant No.20031017) 

主　　题：二价铜 CopC 蛋白质结构 构象稳定性 作用 尿素变性 

摘      要：The CopC protein from pseudomonas syringae pathovar tomato is expressed as one of four proteins encoded by the operon CopABCD that is responsible for copper resistance. And there are one trypto-phan (83), one tyrosine (79), and three phenylalanines (35, 43, 99) in apoCopC. The fluorescence peak of apoCopC is located near 320 nm, and the peak shifts toward 353 nm in the presence of 10 mmol·L^(-1) urea with excitation at 280 nm. Using urea as a chemical agent, the conformational stabilities of apoCopC and Cu_N^(2+) -CopC were monitored by fluorescence spectrum in 20 mmol·L^(-1) phosphate buffer and 100 mmol·L^(-1) sodium chloride at pH 6.0. The free energy of stabilization for apoCopC and Cu_N^(2+)-CopC is 16.29±0.65 kJ·mol^(-1) and 26.26±0.35 kJ·mol^(-1), respectively. The distance between the tryptophan residue and the Cu^(2+) in Cu_N^(2+) -CopC has been studied by observing Frster type nonradia-tive energy transfer. And it is calculated to be 11.6 .