title: Nuclear magnetic resonance studies of the solution chemistry of metal complexes. 26. Mixed ligand complexes of cadmium, nitrilotriacetic acid, glutathione, and related ligands.
abstract: The complexation of glutathione and related ligands by the nitrilotriacetic acid complex of Cd2+ (Cd(NTA)-) has been investigated by 1H NMR as a model for the coordination chemistry of Cd2+ and GSH in biological systems. Related ligands included glycine, glutamic acid, cysteine, N-acetylcysteine, penicillamine, N-acetylpenicillamine, mercaptosuccinic acid, and the S-methyl derivative of glutathione. The nature of the complexes formed was deduced from 1H NMR spectra of Cd(NTA)- and the ligands. Mixed ligand complexes (Cd(NTA)L) and single ligand complexes (CdLx) are formed with the thiol ligands, whereas only mixed ligand complexes form with glycine, glutamic acid and S-methylglutathione. Formation constants of the mixed and the single ligand complexes were determined from NMR data. The results indicate that formation constants for binding of a thiolate donor group by Cd2+, either as the free ion or in a coordinately unsaturated complex, are in the range 10(5)-10(6).
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Kadima
authors.forename: D L
authors.initials: DL
authors.lastname: Rabenstein
mesh_terms: D000085:Acetates / Q000032:analysis*; D002104:Cadmium / Q000032:analysis*; D002614:Chelating Agents; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005978:Glutathione / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D009571:Nitrilotriacetic Acid / Q000032:analysis*; D012996:Solutions
chemical_list: D000085:Acetates; D002614:Chelating Agents; D008024:Ligands; D012996:Solutions; D002104:Cadmium; D005978:Glutathione; D009571:Nitrilotriacetic Acid