title: Cobaloxime-based artificial hydrogenases.
abstract: Cobaloximes are popular H2 evolution molecular catalysts but have so far mainly been studied in nonaqueous conditions. We show here that they are also valuable for the design of artificial hydrogenases for application in neutral aqueous solutions and report on the preparation of two well-defined biohybrid species via the binding of two cobaloxime moieties, {Co(dmgH)2} and {Co(dmgBF2)2} (dmgH2 = dimethylglyoxime), to apo Sperm-whale myoglobin (SwMb). All spectroscopic data confirm that the cobaloxime moieties are inserted within the binding pocket of the SwMb protein and are coordinated to a histidine residue in the axial position of the cobalt complex, resulting in thermodynamically stable complexes. Quantum chemical/molecular mechanical docking calculations indicated a coordination preference for His93 over the other histidine residue (His64) present in the vicinity. Interestingly, the redox activity of the cobalt centers is retained in both biohybrids, which provides them with the catalytic activity for H2 evolution in near-neutral aqueous conditions.
authors.affiliation: Laboratory of Chemistry and Biology of Metals, Université Grenoble Alpes, CNRS, CEA , 17 rue des Martyrs, F-38000 Grenoble, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Bacchi
authors.forename: Gustav
authors.initials: G
authors.lastname: Berggren
authors.forename: Jens
authors.initials: J
authors.lastname: Niklas
authors.forename: Elias
authors.initials: E
authors.lastname: Veinberg
authors.forename: Michael W
authors.initials: MW
authors.lastname: Mara
authors.forename: Megan L
authors.initials: ML
authors.lastname: Shelby
authors.forename: Oleg G
authors.initials: OG
authors.lastname: Poluektov
authors.forename: Lin X
authors.initials: LX
authors.lastname: Chen
authors.forename: David M
authors.initials: DM
authors.lastname: Tiede
authors.forename: Christine
authors.initials: C
authors.lastname: Cavazza
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Field
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.forename: Vincent
authors.initials: V
authors.lastname: Artero
mesh_terms: D002384:Catalysis; D002942:Circular Dichroism; D003035:Cobalt / Q000737:chemistry; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D006864:Hydrogenase / Q000737:chemistry*; D062105:Molecular Docking Simulation; D009942:Organometallic Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009942:Organometallic Compounds; C556179:cobaloxime; D003035:Cobalt; D006864:Hydrogenase