dc.contributor.author | Murphy, BJ | en_US |
dc.contributor.author | Hidalgo, R | en_US |
dc.contributor.author | Roessler, MM | en_US |
dc.contributor.author | Evans, RM | en_US |
dc.contributor.author | Ash, PA | en_US |
dc.contributor.author | Myers, WK | en_US |
dc.contributor.author | Vincent, KA | en_US |
dc.contributor.author | Armstrong, FA | en_US |
dc.date.accessioned | 2016-04-25T09:50:01Z | |
dc.date.issued | 2015-07-08 | en_US |
dc.date.submitted | 2016-03-30T21:46:24.461Z | |
dc.identifier.uri | http://qmro.qmul.ac.uk/xmlui/handle/123456789/12036 | |
dc.description.abstract | Despite extensive studies on [NiFe]-hydrogenases, the mechanism by which these enzymes produce and activate H2 so efficiently remains unclear. A well-known EPR-active state produced under H2 and known as Ni-C is assigned as a Ni(III)-Fe(II) species with a hydrido ligand in the bridging position between the two metals. It has long been known that low-temperature photolysis of Ni-C yields distinctive EPR-active states, collectively termed Ni-L, that are attributed to migration of the bridging-H species as a proton; however, Ni-L has mainly been regarded as an artifact with no mechanistic relevance. It is now demonstrated, based on EPR and infrared spectroscopic studies, that the Ni-C to Ni-L interconversion in Hydrogenase-1 (Hyd-1) from Escherichia coli is a pH-dependent process that proceeds readily in the dark-proton migration from Ni-C being favored as the pH is increased. The persistence of Ni-L in Hyd-1 must relate to unassigned differences in proton affinities of metal and adjacent amino acid sites, although the unusually high reduction potentials of the adjacent Fe-S centers in this O2-tolerant hydrogenase might also be a contributory factor, impeding elementary electron transfer off the [NiFe] site after proton departure. The results provide compelling evidence that Ni-L is a true, albeit elusive, catalytic intermediate of [NiFe]-hydrogenases. | en_US |
dc.description.sponsorship | The research was supported by the UK BBSRC (BB/I022309/1 and BB/L009722/1). F.A.A. is a Royal Society-Wolfson Research Merit Award holder. W.K.M. is supported by the UK EPSRC (EP/L011972/1, grant to CAESR, the Centre for Advanced Spin Resonance). K.A.V. and P.A.A. are supported by the European Research Council (EnergyBioCatalysis-ERC-2010-StG-258600). R.H. is supported by Ministerio de Ciencia y Tecnología, Universidad de Costa Rica and Lincoln College, Oxford. | en_US |
dc.format.extent | 8484 - 8489 | en_US |
dc.language | eng | en_US |
dc.relation.ispartof | J Am Chem Soc | en_US |
dc.rights | ACS AuthorChoice - This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. | |
dc.subject | Carbon | en_US |
dc.subject | Catalytic Domain | en_US |
dc.subject | Electron Spin Resonance Spectroscopy | en_US |
dc.subject | Electrons | en_US |
dc.subject | Escherichia coli | en_US |
dc.subject | Escherichia coli Proteins | en_US |
dc.subject | Hydrogen | en_US |
dc.subject | Hydrogen-Ion Concentration | en_US |
dc.subject | Hydrogenase | en_US |
dc.subject | Ligands | en_US |
dc.subject | Metals | en_US |
dc.subject | Nickel | en_US |
dc.subject | Nitrogen | en_US |
dc.subject | Oxidation-Reduction | en_US |
dc.subject | Oxygen | en_US |
dc.subject | Photolysis | en_US |
dc.subject | Protons | en_US |
dc.subject | Temperature | en_US |
dc.title | Discovery of Dark pH-Dependent H(+) Migration in a [NiFe]-Hydrogenase and Its Mechanistic Relevance: Mobilizing the Hydrido Ligand of the Ni-C Intermediate. | en_US |
dc.type | Article | |
dc.identifier.doi | 10.1021/jacs.5b03182 | en_US |
pubs.author-url | https://www.ncbi.nlm.nih.gov/pubmed/26103582 | en_US |
pubs.issue | 26 | en_US |
pubs.notes | Not known | en_US |
pubs.publication-status | Published | en_US |
pubs.volume | 137 | en_US |