title: Mechanism of hydrogen evolution catalyzed by NiFe hydrogenases: insights from a Ni-Ru model compound.
abstract: DFT modeling has been used to investigate a previously proposed mechanism of proton reduction catalyzed by [Ni(xbsms)Ru(CO)(2)Cl(2)] (H(2)xbsms = 1,2-bis(4-mercapto-3,3-dimethyl-2-thiabutyl)benzene), a bio-inspired mimic of NiFe hydrogenases based on a Ni-Ru framework. Protonation of the 2e(-)-reduced compound, from which a chloride anion has been eliminated, results in the formation of a semi-bridging hydride derivative with structural features comparable to those of the Ni-C state catalytic intermediate of native hydrogenases. The present study thus provides structural and functional insights into the enzymatic mechanism including the possible involvement of a bridging hydride derivative and heterolytic formation of a dihydrogen molecule on a {Ni(mu-S)(2)M} framework.
authors.affiliation: Laboratoire de Dynamique Moléculaire, Institut de Biologie Structurale Jean-Pierre Ebel, UMR CNRS/UJF/CEA 5075, 41 rue Jules Horowitz F-38027, Grenoble cedex 1, France.
authors.forename: Loredana
authors.initials: L
authors.lastname: Vaccaro
authors.forename: Vincent
authors.initials: V
authors.lastname: Artero
authors.forename: Sigolène
authors.initials: S
authors.lastname: Canaguier
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Field
mesh_terms: D055162:Biocatalysis; D020134:Catalytic Domain; D004789:Enzyme Activation; D006859:Hydrogen / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D011487:Protein Conformation; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D009532:Nickel; D012428:Ruthenium; D006859:Hydrogen; C043296:nickel-iron hydrogenase; D006864:Hydrogenase