Comprehensive structural, infrared spectroscopic and kinetic investigations of the roles of the active-site arginine in bidirectional hydrogen activation by the [NiFe]-hydrogenase ‘Hyd-2’ from <i>Escherichia coli</i>
Rhiannon M. Evans, Stephen E. Beaton, Patricia Rodríguez‐Maciá, Yunjie Pang, K. Wong, Leonie Kertess, William K. Myers, Ragnar Björnsson, Philip A. Ash, Kylie A. Vincent, S.B. Carr, Fräser A. Armstrong
Abstract
oxidation that is not linked to an increased H/D isotope effect. Native electrocatalytic reversibility is retained. The results show that the sluggish kinetics observed for the lysine variant arise most obviously because the advantage of a more favourable low-energy pathway is massively offset by an extremely unfavourable activation entropy. Extensive efforts to establish the identity of the diatomic ligand, the tight binding of which is an unexpected further consequence of replacing the pendant arginine, prove inconclusive.
Topics & Concepts
HydrogenaseChemistryDiatomic moleculeActive siteLigand (biochemistry)CrystallographyArginineHydrogen bondMoleculeStereochemistryHydrogenPhotochemistryCatalysisAmino acidOrganic chemistryBiochemistryReceptorMetalloenzymes and iron-sulfur proteinsElectrocatalysts for Energy ConversionHydrogen Storage and Materials