Preparation and Coordination Characterization of Glutathione-Zn2+ Complex

Abstract

Glutathione (GSH)-Zn²⁺ complex was prepared using a dialysis-lyophilization method, the coordination ratio of the prepared complex was determined to be: GSH:Zn²⁺ » 2:1. IR, ¹H NMR and atomic force microscope tests indicated that the binding sites between glutathione and Zn²⁺ are the carbonyl oxygen in the amide group (Cys residue) and sulfur atom in the thiol groups. A coordination structure of the complex was proposed according to the coordination ratio and the bonding sites of glutathione. Further investigation demonstrated that the capability of GSHZn²⁺ complex to restrain hydroxyl and super-oxide radicals is stronger than that of free glutathione molecule.