Imperial College London
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DrMaxieRoessler

Faculty of Natural Sciences, Department of Chemistry

Reader in EPR Spectroscopy
 
 
 
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Contact

 

+44 (0)20 7594 9861m.roessler Website

 
 
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Location

 

301AMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Murphy:2015:10.1021/jacs.5b03182,
author = {Murphy, BJ and Hidalgo, R and Roessler, MM and Evans, RM and Ash, PA and Myers, WK and Vincent, KA and Armstrong, FA},
doi = {10.1021/jacs.5b03182},
journal = {Journal of the American Chemical Society},
pages = {8484--8489},
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},
url = {http://dx.doi.org/10.1021/jacs.5b03182},
volume = {137},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - 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 NiIII–FeII 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.
AU  - Murphy,BJ
AU  - Hidalgo,R
AU  - Roessler,MM
AU  - Evans,RM
AU  - Ash,PA
AU  - Myers,WK
AU  - Vincent,KA
AU  - Armstrong,FA
DO  - 10.1021/jacs.5b03182
EP  - 8489
PY  - 2015///
SN  - 0002-7863
SP  - 8484
TI  - Discovery of dark pH-dependent H+ migration in a [NiFe]-hydrogenase and Its mechanistic relevance: mobilizing the hydrido ligand of the Ni-C intermediate
T2  - Journal of the American Chemical Society
UR  - http://dx.doi.org/10.1021/jacs.5b03182
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000357964400033&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://pubs.acs.org/doi/10.1021/jacs.5b03182
VL  - 137
ER  -
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