Reversible Glutamate Coordination to High-Valent Nickel Protects the Active Site of a [NiFe] Hydrogenase from Oxygen.

Autor:	Kulka-Peschke CJ; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Schulz AC; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Lorent C; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Rippers Y; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany., Wahlefeld S; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Preissler J; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Schulz C; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Wiemann C; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Bernitzky CCM; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany., Karafoulidi-Retsou C; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Wrathall SLD; Department of Chemistry & York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K., Procacci B; Department of Chemistry & York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K., Matsuura H; Life Science Research Infrastructure Group, RIKEN/SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan., Greetham GM; STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxford OX11 0QX, U.K., Teutloff C; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany., Lauterbach L; Institute of Applied Microbiology, Synthetic Microbiology, RWTH Aachen University, Worringer Weg 1, D-52074 Aachen, Germany., Higuchi Y; Graduate School of Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan., Ishii M; Graduate School of Agricultural and Life Sciences / Faculty of Agriculture, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan., Hunt NT; Department of Chemistry & York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K., Lenz O; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Zebger I; Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany., Horch M; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
Jazyk:	angličtina
Zdroj:	Journal of the American Chemical Society [J Am Chem Soc] 2022 Sep 21; Vol. 144 (37), pp. 17022-17032. Date of Electronic Publication: 2022 Sep 09.
DOI:	10.1021/jacs.2c06400
Abstrakt:	NAD + -reducing [NiFe] hydrogenases are valuable biocatalysts for H 2 -based energy conversion and the regeneration of nucleotide cofactors. While most hydrogenases are sensitive toward O 2 and elevated temperatures, the soluble NAD + -reducing [NiFe] hydrogenase from Hydrogenophilus thermoluteolus ( Ht SH) is O 2 -tolerant and thermostable. Thus, it represents a promising candidate for biotechnological applications. Here, we have investigated the catalytic activity and active-site structure of native Ht SH and variants in which a glutamate residue in the active-site cavity was replaced by glutamine, alanine, and aspartate. Our biochemical, spectroscopic, and theoretical studies reveal that at least two active-site states of oxidized Ht SH feature an unusual architecture in which the glutamate acts as a terminal ligand of the active-site nickel. This observation demonstrates that crystallographically observed glutamate coordination represents a native feature of the enzyme. One of these states is diamagnetic and characterized by a very high stretching frequency of an iron-bound active-site CO ligand. Supported by density-functional-theory calculations, we identify this state as a high-valent species with a biologically unprecedented formal Ni(IV) ground state. Detailed insights into its structure and dynamics were obtained by ultrafast and two-dimensional infrared spectroscopy, demonstrating that it represents a conformationally strained state with unusual bond properties. Our data further show that this state is selectively and reversibly formed under oxic conditions, especially upon rapid exposure to high O 2 levels. We conclude that the kinetically controlled formation of this six-coordinate high-valent state represents a specific and precisely orchestrated stereoelectronic response toward O 2 that could protect the enzyme from oxidative damage.
Databáze:	MEDLINE
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