title: Oriented immobilization of Desulfovibrio gigas hydrogenase onto carbon electrodes by covalent bonds for nonmediated oxidation of H2.
abstract: The orientation of hydrogenase bound covalently to a pyrolytic graphite edge electrode modified with a 4-aminophenyl monolayer can be modulated via electrostatic interactions during the immobilization step. At low ionic strength and when the amino groups of the electrode surface are mostly protonated, the hydrogenase is immobilized with the negatively charged region that surrounds its 4Fe4S cluster nearer to the protein surface facing the electrode. This allows direct electron transfer between the immobilized hydrogenase and the electrode, which is observed by the strong catalytic currents measured in the presence of the H2 substrate. Therefore, a very stable enzymatic electrode is produced that catalyzes nonmediated H2 oxidation.
authors.affiliation: Instituto de Catalisis, CSIC, C/Marie Curie 2, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Olaf
authors.initials: O
authors.lastname: Rüdiger
authors.forename: Jose M
authors.initials: JM
authors.lastname: Abad
authors.forename: E Claude
authors.initials: EC
authors.lastname: Hatchikian
authors.forename: Victor M
authors.initials: VM
authors.lastname: Fernandez
authors.forename: Antonio L
authors.initials: AL
authors.lastname: De Lacey
mesh_terms: D002244:Carbon / Q000737:chemistry*; D045286:Desulfovibrio gigas / Q000201:enzymology*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D017434:Protein Structure, Tertiary
chemical_list: D004800:Enzymes, Immobilized; D002244:Carbon; D006859:Hydrogen; D006864:Hydrogenase