title: Kinetic study of nickel-thiolate oxygenation by hydrogen peroxide. Implications for nickel-containing superoxide dismutase.
abstract: The rate of metal-thiolate oxygenation by hydrogen peroxide has been measured for a model complex of nickel-containing superoxide dismutase (NiSOD) as 0.47 ± 0.03 M(-1) s(-1) at 303 K. Under typical synthetic conditions the reaction proceeds within seconds yielding S-oxygenate products. At biologically relevant H(2)O(2) concentrations, half-life times extend to several hours or days. The results suggest H(2)O(2) oxidation of NiSOD is not kinetically competent on the SOD timescale accounting for the lack of S-oxygenation byproducts.
authors: Department of Chemistry, University of Louisville, Louisville, KY 40292, USA.
authors: Donald R
authors: DR
authors: Herdt
authors: Craig A
authors: CA
authors: Grapperhaus
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D009532:Nickel; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D010100:Oxygen