title: Orientation-Controlled Electrocatalytic Efficiency of an Adsorbed Oxygen-Tolerant Hydrogenase.
abstract: Protein immobilization on electrodes is a key concept in exploiting enzymatic processes for bioelectronic devices. For optimum performance, an in-depth understanding of the enzyme-surface interactions is required. Here, we introduce an integral approach of experimental and theoretical methods that provides detailed insights into the adsorption of an oxygen-tolerant [NiFe] hydrogenase on a biocompatible gold electrode. Using atomic force microscopy, ellipsometry, surface-enhanced IR spectroscopy, and protein film voltammetry, we explore enzyme coverage, integrity, and activity, thereby probing both structure and catalytic H2 conversion of the enzyme. Electrocatalytic efficiencies can be correlated with the mode of protein adsorption on the electrode as estimated theoretically by molecular dynamics simulations. Our results reveal that pre-activation at low potentials results in increased current densities, which can be rationalized in terms of a potential-induced re-orientation of the immobilized enzyme.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Heidary
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Tillmann
authors.initials: T
authors.lastname: Utesch
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Zerball
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Horch
authors.affiliation: Biomolecular Spectroscopy/LaserLaB Amsterdam, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands.
authors.forename: Diego
authors.initials: D
authors.lastname: Millo
authors.affiliation: Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Chausseestraße 117, D-10115, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Fritsch
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Lenz
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: von Klitzing
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hildebrandt
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.|Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, D-79104, Freiburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Fischer
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Maria Andrea
authors.initials: MA
authors.lastname: Mroginski
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135 & 124, D-10623, Berlin, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Zebger
mesh_terms: D000327:Adsorption; D055162:Biocatalysis / Q000187:drug effects; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004795:Enzyme Stability / Q000187:drug effects; D004800:Enzymes, Immobilized / Q000378:metabolism; D006864:Hydrogenase / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry; D010100:Oxygen / Q000494:pharmacology*; D043367:Ralstonia / Q000201:enzymology; D013055:Spectrophotometry, Infrared
chemical_list: D004800:Enzymes, Immobilized; C043296:nickel-iron hydrogenase; D006864:Hydrogenase; D010100:Oxygen