Reaction Coordinate Leading to H 2 Production in [FeFe]-Hydrogenase Identified by Nuclear Resonance Vibrational Spectroscopy and Density Functional Theory.

Autor: Pelmenschikov V; Institut für Chemie, Technische Universität Berlin , Strasse des 17 Juni 135, 10623 Berlin, Germany., Birrell JA; Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany., Pham CC; Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States., Mishra N; Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States., Wang H; Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States., Sommer C; Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany., Reijerse E; Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany., Richers CP; School of Chemical Sciences, University of Illinois , 600 S. Mathews Avenue, Urbana, Illinois 61801, United States., Tamasaku K; JASRI , Spring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5198, Japan., Yoda Y; JASRI , Spring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5198, Japan., Rauchfuss TB; School of Chemical Sciences, University of Illinois , 600 S. Mathews Avenue, Urbana, Illinois 61801, United States., Lubitz W; Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany., Cramer SP; Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States.
Jazyk: angličtina
Zdroj: Journal of the American Chemical Society [J Am Chem Soc] 2017 Nov 22; Vol. 139 (46), pp. 16894-16902. Date of Electronic Publication: 2017 Nov 09.
DOI: 10.1021/jacs.7b09751
Abstrakt: [FeFe]-hydrogenases are metalloenzymes that reversibly reduce protons to molecular hydrogen at exceptionally high rates. We have characterized the catalytically competent hydride state (H hyd ) in the [FeFe]-hydrogenases from both Chlamydomonas reinhardtii and Desulfovibrio desulfuricans using 57 Fe nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT). H/D exchange identified two Fe-H bending modes originating from the binuclear iron cofactor. DFT calculations show that these spectral features result from an iron-bound terminal hydride, and the Fe-H vibrational frequencies being highly dependent on interactions between the amine base of the catalytic cofactor with both hydride and the conserved cysteine terminating the proton transfer chain to the active site. The results indicate that H hyd is the catalytic state one step prior to H 2 formation. The observed vibrational spectrum, therefore, provides mechanistic insight into the reaction coordinate for H 2 bond formation by [FeFe]-hydrogenases.
Databáze: MEDLINE
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