Infrared Spectroscopy During Electrocatalytic Turnover Reveals the Ni-L Active Site State During H2 Oxidation by a NiFe Hydrogenase.
journal contributionposted on 2019-06-03, 13:40 authored by Ricardo Hidalgo, Philip A. Ash, Adam J. Healy, Kylie A. Vincent
A novel in situ IR spectroscopic approach is demonstrated for the characterization of hydrogenase during catalytic turnover. E. coli hydrogenase 1 (Hyd-1) is adsorbed on a high surface-area carbon electrode and subjected to the same electrochemical control and efficient supply of substrate as in protein film electrochemistry during spectral acquisition. The spectra reveal that the active site state known as Ni-L, observed in other NiFe hydrogenases only under illumination or at cryogenic temperatures, can be generated reversibly in the dark at ambient temperature under both turnover and non-turnover conditions. The observation that Ni-L is present at all potentials during turnover under H2 suggests that the final steps in the catalytic cycle of H2 oxidation by Hyd-1 involve sequential proton and electron transfer via Ni-L. A broadly applicable IR spectroscopic technique is presented for addressing electrode-adsorbed redox enzymes under fast catalytic turnover.
This work was supported by: European Research Council (EnergyBioCatalysis‐ERC‐2010‐StG‐258600); Biotechnology and Biological Sciences Research Council (BB/L009722/1); Engineering and Physical Sciences Research Council (EP/K031503/1). R.H. is supported by Ministerio de Ciencia y Tecnología, Universidad de Costa Rica, and Lincoln College, Oxford. We thank E. Nomerotskaia for preparing E. coli Hyd‐1.
CitationAngewandte Chemie International Edition English, 2015, 54 (24), pp. 7110-7113
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Chemistry
- VoR (Version of Record)
Published inAngewandte Chemie International Edition English
PublisherWiley for Gesellschaft Deutscher Chemiker (GDCh)
NotesSupporting information for this article is available on the WWW under http://dx.doi.org/10.1002/anie.201502338.
IR spectroscopybiocatalysiselectrochemistryhydrogenasein situ spectroscopyBiocatalysisCatalytic DomainElectrochemical TechniquesElectrodesElectron Spin Resonance SpectroscopyElectron TransportEscherichia coliEscherichia coli ProteinsHydrogenHydrogenaseLigandsNickelOxidation-ReductionProtonsSpectrophotometry, Infrared