Coordination chemistry of glutathione

The metal ion coordination abilities of reduced and oxidized glutathione ar e reviewed. Reduced glutathione (GSH) is a very versatile ligand, forming s table complexes with both hard and soft metal ions. Several general binding modes of GSH are described. Soft metal ions coordinate exclusively or prim arily through thiol sulfur. Hard ones prefer the amino acid-like moiety of the glutamic acid residue. Several transition metal ions can additionally c oordinate to the peptide nitrogen of the gamma-Glu-Cys bond. Oxidized gluta thione lacks the thiol function. Nevertheless, it proves to be a surprising ly efficient ligand for a range of metal ions, coordinating them primarily through the donors of the glutamic acid residue.