1. Hydride bridge in [NiFe]-hydrogenase observed by nuclear resonance vibrational spectroscopy.
- Author
-
Ogata H, Krämer T, Wang H, Schilter D, Pelmenschikov V, van Gastel M, Neese F, Rauchfuss TB, Gee LB, Scott AD, Yoda Y, Tanaka Y, Lubitz W, and Cramer SP
- Subjects
- Magnetic Resonance Spectroscopy, Desulfovibrio vulgaris enzymology, Hydrogenase chemistry
- Abstract
The metabolism of many anaerobes relies on [NiFe]-hydrogenases, whose characterization when bound to substrates has proven non-trivial. Presented here is direct evidence for a hydride bridge in the active site of the (57)Fe-labelled fully reduced Ni-R form of Desulfovibrio vulgaris Miyazaki F [NiFe]-hydrogenase. A unique 'wagging' mode involving H(-) motion perpendicular to the Ni(μ-H)(57)Fe plane was studied using (57)Fe-specific nuclear resonance vibrational spectroscopy and density functional theory (DFT) calculations. On Ni(μ-D)(57)Fe deuteride substitution, this wagging causes a characteristic perturbation of Fe-CO/CN bands. Spectra have been interpreted by comparison with Ni(μ-H/D)(57)Fe enzyme mimics [(dppe)Ni(μ-pdt)(μ-H/D)(57)Fe(CO)3](+) and DFT calculations, which collectively indicate a low-spin Ni(II)(μ-H)Fe(II) core for Ni-R, with H(-) binding Ni more tightly than Fe. The present methodology is also relevant to characterizing Fe-H moieties in other important natural and synthetic catalysts.
- Published
- 2015
- Full Text
- View/download PDF