物理化学学报 >> 2010, Vol. 26 >> Issue (12): 3225-3229.doi: 10.3866/PKU.WHXB20101213

结构化学 上一篇    下一篇

硒代蛋氨酸与铜离子的相互作用

王锐1, 白燕1, 梁志红2, 刘莺1, 黄莉莉1, 郑文杰1   

  1. 1. 暨南大学化学系, 广州510632;
    2. 暨南大学分析测试中心, 广州510632
  • 收稿日期:2010-07-02 修回日期:2010-10-08 发布日期:2010-12-01
  • 通讯作者: 白燕, 郑文杰 E-mail:tbaiyan@jnu.edu.cn, tzhengwj@jnu.edu.cn
  • 基金资助:

    国家自然科学基金(20771044)和广东省自然科学基金(8251063201000008)资助项目

Interaction between Selenomethionine and Copper Ions

WANG Rui1, BAI Yan1, LIANG Zhi-Hong2, LIU Ying1, HUANG Li-Li1, ZHENG Wen-Jie1   

  1. 1. Department of Chemistry, Jinan University, Guangzhou 510632, P. R. China;
    2. Experiment and Technology Center, Jinan University, Guangzhou 510632, P. R. China
  • Received:2010-07-02 Revised:2010-10-08 Published:2010-12-01
  • Contact: BAI Yan, ZHENG Wen-Jie E-mail:tbaiyan@jnu.edu.cn, tzhengwj@jnu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20771044) and Natural Science Foundation of Guangdong Province, China (8251063201000008).

摘要:

采用循环伏安法和库仑法研究了硒代蛋氨酸(SeMet)与铜离子的相互作用. 当SeMet不存在时, 铜离子在-132和71 mV有一对氧化还原峰(峰V, VI). 当铜离子与SeMet共存时, 配合物在14, 128, 271, -194 mV有4 个峰(峰I, II, III, IV). 扫描电位从600 mV 到-600 mV 时, Cu(II)-(SeMet)2 配合物在14 mV 时被还原为Cu(I)-SeMet 配合物; Cu(I)-SeMet 配合物在-194 mV被还原为Cu(0)和SeMet. 由-600 mV回扫时, 还原产物被逐次氧化为Cu(I)-SeMet 配合物(128 mV)和Cu(II)-(SeMet)2配合物(271 mV). 同时发现Cu(I)-SeMet 配合物在电位-100 mV至200 mV间是稳定的, Cu(I)的氧化还原过程被观察到. 此外, 采用毛细管电泳法测得二元Cu-SeMet配合物的稳定常数(K1K2)分别为2.24×107和2.24×106. 最后, 推测Cu-SeMet配合物的结构为: 在pH 3.9 时, 铜离子通过Cu—Se和Cu—OCO键与SeMet发生配位作用; 在生理条件时, 铜离子通过Cu—N和Cu—OCO键与SeMet发生配位作用.

关键词: 铜离子, 硒代蛋氨酸, 电化学特性, 配位结构, 毛细管电泳

Abstract:

The binary Cu-selenomethionine (SeMet) complex was investigated using voltammetry and chronocoulometry. A pair of peaks (V, VI) were observed at -132 and 71 mV in the Cu(NO3)2 solution. When SeMet and Cu(NO3)2 coexisted, four peaks (I, II, III, and IV) were observed at 14, 128, 271, and -194 mV, respectively. From the 600 to -600 mV potential scan, we observed that the Cu(II)-(SeMet)2 complex was reduced to Cu(I)-SeMet complex at 14 mV and then the Cu(I)-SeMet complex was reduced to Cu(0) and SeMet at -194 mV. After reaching -600 mV the potential was reversed and the reduced product was oxidized to the Cu(I)-SeMet complex at 128 mV and Cu(II)-(SeMet)2 complex at 271 mV. The Cu(I)-SeMet complex was stable from about -100 to 200 mV and a redox process was observed for Cu(I). The stability constants of the binary Cu-SeMet complex, 2.24×107 (K1) and 2.24×106 (K2), were determined by capillary electrophoresis. We proposed the structures of Cu-SeMet complexes: Copper coordinated with SeMet by the formation of Cu—Se and Cu—OCO bonds at pH 3.9 or by the formation of Cu—N and Cu—OCO bonds under physiological conditions.

Key words: Copper ion, Selenomethionine, Electrochemical characteristic, Coordination structure, Capillary electrophoresis

MSC2000: 

  • O641