Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (12): 3225-3229.doi: 10.3866/PKU.WHXB20101213

• STRUCTURE CHEMISTRY • Previous Articles     Next Articles

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).

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