title: Redox activities of mono- and binuclear forms of low-molecular and protein-bound dinitrosyl iron complexes with thiol-containing ligands.
abstract: EPR, optical, electrochemical and stopped-flow methods were used to demonstrate that Fe(NO)2 fragments in paramagnetic mononuclear and diamagnetic binuclear forms of dinitrosyl iron complexes with glutathione are reversibly reduced by a two-electron mechanism to be further transformed from the initial state with d(7) configuration into states with the d(8) and d(9) electronic configurations of the iron atom. Under these conditions, both forms of DNIC display identical optical and EPR characteristics in state d(9) suggesting that reduction of the binuclear form of DNIC initiates their reversible decomposition into two mononuclear dinitrosyl iron fragments, one of which is EPR-silent (d(8)) and the other one is EPR-active (d(9)). Both forms of DNIC produce EPR signals with the following values of the g-factor: g⊥=2.01, g||=1.97, gaver.=2.0. M-DNIC with glutathione manifest an ability to pass into state d(9), however, only in solutions with a low content of free glutathione. Similar transitions were established for protein-bound М- and B-DNIC with thiol-containing ligands.
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Rostislav R
authors.initials: RR
authors.lastname: Borodulin
authors.affiliation: Ivanovo State University of Chemistry and Technology, Ivanovo, Russia; Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Germany.
authors.forename: Ilia А
authors.initials: IА
authors.lastname: Dereven'kov
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Dosymzhan Sh
authors.initials: DSh
authors.lastname: Burbaev
authors.affiliation: Ivanovo State University of Chemistry and Technology, Ivanovo, Russia.
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Makarov
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Vasak D
authors.initials: VD
authors.lastname: Mikoyan
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Vladimir А
authors.initials: VА
authors.lastname: Serezhenkov
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Lyudmila N
authors.initials: LN
authors.lastname: Kubrina
authors.affiliation: Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Germany.
authors.forename: Ivana
authors.initials: I
authors.lastname: Ivanovic-Burmazovic
authors.affiliation: N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia. Electronic address: vanin@polymer.chph.ras.ru.
authors.forename: Anatoly F
authors.initials: AF
authors.lastname: Vanin
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005978:Glutathione / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008970:Molecular Weight; D009589:Nitrogen Oxides / Q000737:chemistry*; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D008024:Ligands; D009589:Nitrogen Oxides; D013438:Sulfhydryl Compounds; C073661:dinitrosyl iron complex; D007501:Iron; D005978:Glutathione
keywords: Cyclic voltammetry; Dinitrosyl iron complexes; Redox conversions