The role of glutathione in cadmium ion detoxification: coordination modes and binding properties--a density functional study.

In this investigation the reduced form of glutathione molecule (GSH) was considered as a model in the coordination chemistry of Cd(2+) and group thiol-containing peptides. Three different forms of GSH, corresponding to the prevalent ones in gas-phase and in aqueous solution, were taken into account in the metallation process. The obtained complexes were characterized at the density functional B3LYP level with the purpose to give better insight in the chelation mechanism of GSH with heavy metal ions in living organisms. Solvent effects, whether with explicit water molecules or with polarizable continuum model (PCM), were considered on the most stable cadmium-complexes obtained by every GSH charged species examined.