title: Nickel (II) complexes of histidyl-peptides as Fenton-reaction catalysts.
abstract: Addition of histidyl-peptides containing the glycyl-glycyl-L-histidyl sequence stimulated the catalysis of Ni(II) hydrogen peroxide reduction. Maximum bleaching of murexide or nitrosodimethylaniline was obtained with glycyl-glycyl-L-histidine. A decrease in the bleaching rates was observed upon addition of SOD or hydroxyl radical scavengers, showing that the hydrogen peroxide/Ni(II)/glycyl-glycyl-L-histidine system generated superoxide anions as well as hydroxyl radicals. In contrast, addition of glycyl-glycyl-L-histidine inhibited the Cu(II) hydrogen peroxide reduction. When peptides or proteins were exposed to oxygen radicals produced by Ni(II)/glycyl-glycyl-L-histidine catalysis of hydrogen peroxide reduction, the observed effects were similar to those produced by oxygen radicals generated by water radiolysis or by Fe(II) or Cu(II) mediated Fenton-reactions: hydroxylation of phenylalanine, interchange of disulfides, destruction of tryptophans and dityrosine formation.
authors.affiliation: INSERM Unité 58-60, Montpellier, France.
authors.forename: J
authors.initials: J
authors.lastname: Torreilles
authors.forename: M C
authors.initials: MC
authors.lastname: Guerin
authors.forename: A
authors.initials: A
authors.lastname: Slaoui-Hasnaoui
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D002614:Chelating Agents / Q000494:pharmacology; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D009114:Murexide; D009532:Nickel / Q000494:pharmacology*; D009603:Nitroso Compounds; D010084:Oxidation-Reduction; D010455:Peptides / Q000494:pharmacology*; D011506:Proteins / Q000187:drug effects; D013481:Superoxides / Q000378:metabolism
chemical_list: D002614:Chelating Agents; D005609:Free Radicals; D009603:Nitroso Compounds; D010455:Peptides; D011506:Proteins; D013481:Superoxides; C008651:4-nitrosodimethylaniline; D009114:Murexide; D009532:Nickel; D006861:Hydrogen Peroxide