title: Versatile methodology toward NiN(2)S(2) complexes as nickel superoxide dismutase models: structure and proton affinity.
abstract: Structural features of the reduced form of the nickel superoxide dismutase (Ni-SOD) active site have been modeled with asymmetric NiN(2)S(2) complexes (Et(4)N)[Ni(nmp)(SR)] (R = C(6)H(4)-p-Cl (2) and (S(t)Bu) (3)) obtained via S,S-bridge splitting of the dimeric metallosynthon, [Ni(2)(nmp)(2)] (1). Complexes 2 and 3 are irreversibly oxidized at potentials within the window needed for SOD activity, 236 and 75 mV versus Ag/AgCl, respectively. The exogenous thiolato-S in 2 and 3 serves as a proton acceptor, suggesting potential involvement of Cys6 in Ni-SOD for H(+) storage between SOD half reactions.
authors.affiliation: Department of Chemistry, University of Georgia, 1001 Cedar St, Athens, Georgia 30602, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Gale
authors.forename: Ashis K
authors.initials: AK
authors.lastname: Patra
authors.forename: Todd C
authors.initials: TC
authors.lastname: Harrop
mesh_terms: D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D011522:Protons; D013482:Superoxide Dismutase / Q000737:chemistry*
chemical_list: D011522:Protons; D009532:Nickel; D013482:Superoxide Dismutase