title: Antioxidant and electron donating function of hypothalamic polypeptides: galarmin and Gx-NH2.
abstract: Chemical mechanisms of antioxidant and electron donating function of the hypothalamic proline-rich polypeptides have been clarified on the molecular level. The antioxidant-chelating property of Galarmin and Gx-NH(2) was established by their capability to inhibit copper(II) dichloride catalyzed H(2)O(2) decomposition, thus preventing formation of HO(*) and HOO(*) radicals. The antiradical activity of Galarmin and Gx-NH(2) was determined by their ability to react with 2,2-diphenyl-1-picrylhydrazyl radical applying differential pulse voltammetry and UV-Vis spectrophotometry methods. Galarmin manifest antiradical activity towards 2,2-diphenyl-1-picrylhydrazyl radical, depending on the existence of phenolic OH group in tyrosine residue at the end of the molecule. The presence of antiradical activity and reduction properties of Galarmin are confirmed by the existence of an oxidation specific peak in voltammograms made by differential pulse voltammetry at E ( composite function) = 0.795 V vs. Ag/Ag(+) aq.
authors.affiliation: Laboratory of Liquid Phase Free Radical Reactions, A.B.Nalbandyan Institute of Chemical Physics NAS RA, 5/2 Sevak str, Yerevan, 0014, Armenia. tavadyan@ichph.sci.am
authors.forename: L A
authors.initials: LA
authors.lastname: Tavadyan
authors.forename: K A
authors.initials: KA
authors.lastname: Galoian
authors.forename: L A
authors.initials: LA
authors.lastname: Harutunyan
authors.forename: H G
authors.initials: HG
authors.lastname: Tonikyan
authors.forename: A A
authors.initials: AA
authors.lastname: Galoyan
mesh_terms: D023181:Antimicrobial Cationic Peptides; D000975:Antioxidants / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D055664:Electrochemical Techniques; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*
chemical_list: D023181:Antimicrobial Cationic Peptides; D000975:Antioxidants; D016166:Free Radical Scavengers; C540268:PRP-1 peptide; D010455:Peptides; D003300:Copper; D006861:Hydrogen Peroxide; C029892:cupric chloride; D010100:Oxygen