title: May GSH and L-His contribute to intracellular binding of zinc? Thermodynamic and solution structural study of a ternary complex.
abstract: GSH and L-His are abundant biomolecules and likely biological ligands for Zn(II) under certain conditions. Potentiometric titrations provide evidence of formation of ternary Zn(II) complexes with GSH and L-His or D-His with slight stereoselectivity in favour of L-His (ca. 1 log unit of stability constant). The solution structure of the ZnH(GSH)(L-His)(H2O) complex at pH 6.8, determined by NMR, includes tridentate L-His, monodentate (sulfur) GSH, and weak interligand interactions. Calculations of competitivity of this complex for Zn(II) binding at pH 7.4 indicate that it is likely to be formed in vivo under conditions of GSH depletion. Otherwise, GSH alone emerges as a likely Zn(II) carrier.
authors.affiliation: Faculty of Chemistry, University of Wrocław, Joliot-Curie 14, 50-383 Wrocław, Poland. arti@wchuwr.chem.uni.wroc.pl
authors.forename: Artur
authors.initials: A
authors.lastname: Krezel
authors.forename: Jacek
authors.initials: J
authors.lastname: Wójcik
authors.forename: Maciej
authors.initials: M
authors.lastname: Maciejczyk
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bal
mesh_terms: D005978:Glutathione / Q000737:chemistry / Q000378:metabolism*; D006639:Histidine / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011199:Potentiometry / Q000379:methods; D011522:Protons; D012996:Solutions; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008024:Ligands; D011522:Protons; D012996:Solutions; D006639:Histidine; D005978:Glutathione; D015032:Zinc