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Brocks C, Das CK, Duan J, Yadav S, Apfel UP, Ghosh S, Hofmann E, Winkler M, Engelbrecht V, Schäfer LV, Happe T. A Dynamic Water Channel Affects O 2 Stability in [FeFe]-Hydrogenases. CHEMSUSCHEM 2024; 17:e202301365. [PMID: 37830175 DOI: 10.1002/cssc.202301365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023]
Abstract
[FeFe]-hydrogenases are capable of reducing protons at a high rate. However, molecular oxygen (O2 ) induces the degradation of their catalytic cofactor, the H-cluster, which consists of a cubane [4Fe4S] subcluster (4FeH ) and a unique diiron moiety (2FeH ). Previous attempts to prevent O2 -induced damage have focused on enhancing the protein's sieving effect for O2 by blocking the hydrophobic gas channels that connect the protein surface and the 2FeH . In this study, we aimed to block an O2 diffusion pathway and shield 4FeH instead. Molecular dynamics (MD) simulations identified a novel water channel (WH ) surrounding the H-cluster. As this hydrophilic path may be accessible for O2 molecules we applied site-directed mutagenesis targeting amino acids along WH in proximity to 4FeH to block O2 diffusion. Protein film electrochemistry experiments demonstrate increased O2 stabilities for variants G302S and S357T, and MD simulations based on high-resolution crystal structures confirmed an enhanced local sieving effect for O2 in the environment of the 4FeH in both cases. The results strongly suggest that, in wild type proteins, O2 diffuses from the 4FeH to the 2FeH . These results reveal new strategies for improving the O2 stability of [FeFe]-hydrogenases by focusing on the O2 diffusion network near the active site.
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Affiliation(s)
- Claudia Brocks
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Chandan K Das
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Jifu Duan
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Shanika Yadav
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Ulf-Peter Apfel
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Subhasri Ghosh
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Eckhard Hofmann
- Faculty of Biology and Biotechnology, X-ray structure analysis of proteins, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Martin Winkler
- Electrobiotechnology, TUM Campus Straubing, Schulgasse 22, Straubing, 94315, Germany
| | - Vera Engelbrecht
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Lars V Schäfer
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
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2
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Sidabras JW, Stripp ST. A personal account on 25 years of scientific literature on [FeFe]-hydrogenase. J Biol Inorg Chem 2023; 28:355-378. [PMID: 36856864 DOI: 10.1007/s00775-023-01992-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 01/25/2023] [Indexed: 03/02/2023]
Abstract
[FeFe]-hydrogenases are gas-processing metalloenzymes that catalyze H2 oxidation and proton reduction (H2 release) in microorganisms. Their high turnover frequencies and lack of electrical overpotential in the hydrogen conversion reaction has inspired generations of biologists, chemists, and physicists to explore the inner workings of [FeFe]-hydrogenase. Here, we revisit 25 years of scientific literature on [FeFe]-hydrogenase and propose a personal account on 'must-read' research papers and review article that will allow interested scientists to follow the recent discussions on catalytic mechanism, O2 sensitivity, and the in vivo synthesis of the active site cofactor with its biologically uncommon ligands carbon monoxide and cyanide. Focused on-but not restricted to-structural biology and molecular biophysics, we highlight future directions that may inspire young investigators to pursue a career in the exciting and competitive field of [FeFe]-hydrogenase research.
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Affiliation(s)
- Jason W Sidabras
- Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI, USA, 53226.
| | - Sven T Stripp
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany.
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3
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Lorenzi M, Gellett J, Zamader A, Senger M, Duan Z, Rodríguez-Maciá P, Berggren G. Investigating the role of the strong field ligands in [FeFe] hydrogenase: spectroscopic and functional characterization of a semi-synthetic mono-cyanide active site. Chem Sci 2022; 13:11058-11064. [PMID: 36320473 PMCID: PMC9516953 DOI: 10.1039/d2sc02271k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/05/2022] [Indexed: 08/11/2023] Open
Abstract
Artificial maturation of hydrogenases provides a path towards generating new semi-synthetic enzymes with novel catalytic properties. Here enzymes featuring a synthetic asymmetric mono-cyanide cofactor have been prepared using two different hydrogenase scaffolds. Their structure and reactivity was investigated in order to elucidate the design rationale behind the native di-cyanide cofactor, and by extension the second coordination sphere of the active-site pocket. Surprisingly, the choice of host enzyme was found to have a dramatic impact on reactivity. Moreover, the study shows that synthetic manipulations of the active-site can significantly increase inhibitor tolerance, as compared to native [FeFe] hydrogenase, while retaining the enzyme's native capacity for reversible catalysis.
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Affiliation(s)
- Marco Lorenzi
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University Lägerhyddsvägen 1 75120 Uppsala Sweden
| | - Joe Gellett
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford South Parks Road OX1 3QR UK
| | - Afridi Zamader
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University Lägerhyddsvägen 1 75120 Uppsala Sweden
- Laboratoire de Chimie et Biologie des Metaux, iRTSV-LCBM/Biocat, Commissariat à l'Energie Atomique (CEA) Grenoble 17, Rue des Martyrs, UMR 5249 38054 Grenoble Cedex 09 France
| | - Moritz Senger
- Department of Chemistry - Ångström, Physical Chemistry, Uppsala University Lägerhyddsvägen 1 75120 Uppsala Sweden
| | - Zehui Duan
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford South Parks Road OX1 3QR UK
| | - Patricia Rodríguez-Maciá
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford South Parks Road OX1 3QR UK
| | - Gustav Berggren
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University Lägerhyddsvägen 1 75120 Uppsala Sweden
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4
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Stripp ST, Duffus BR, Fourmond V, Léger C, Leimkühler S, Hirota S, Hu Y, Jasniewski A, Ogata H, Ribbe MW. Second and Outer Coordination Sphere Effects in Nitrogenase, Hydrogenase, Formate Dehydrogenase, and CO Dehydrogenase. Chem Rev 2022; 122:11900-11973. [PMID: 35849738 PMCID: PMC9549741 DOI: 10.1021/acs.chemrev.1c00914] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gases like H2, N2, CO2, and CO are increasingly recognized as critical feedstock in "green" energy conversion and as sources of nitrogen and carbon for the agricultural and chemical sectors. However, the industrial transformation of N2, CO2, and CO and the production of H2 require significant energy input, which renders processes like steam reforming and the Haber-Bosch reaction economically and environmentally unviable. Nature, on the other hand, performs similar tasks efficiently at ambient temperature and pressure, exploiting gas-processing metalloenzymes (GPMs) that bind low-valent metal cofactors based on iron, nickel, molybdenum, tungsten, and sulfur. Such systems are studied to understand the biocatalytic principles of gas conversion including N2 fixation by nitrogenase and H2 production by hydrogenase as well as CO2 and CO conversion by formate dehydrogenase, carbon monoxide dehydrogenase, and nitrogenase. In this review, we emphasize the importance of the cofactor/protein interface, discussing how second and outer coordination sphere effects determine, modulate, and optimize the catalytic activity of GPMs. These may comprise ionic interactions in the second coordination sphere that shape the electron density distribution across the cofactor, hydrogen bonding changes, and allosteric effects. In the outer coordination sphere, proton transfer and electron transfer are discussed, alongside the role of hydrophobic substrate channels and protein structural changes. Combining the information gained from structural biology, enzyme kinetics, and various spectroscopic techniques, we aim toward a comprehensive understanding of catalysis beyond the first coordination sphere.
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Affiliation(s)
- Sven T Stripp
- Freie Universität Berlin, Experimental Molecular Biophysics, Berlin 14195, Germany
| | | | - Vincent Fourmond
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, Institut Microbiologie, Bioénergies et Biotechnologie, CNRS, Aix Marseille Université, Marseille 13402, France
| | - Christophe Léger
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, Institut Microbiologie, Bioénergies et Biotechnologie, CNRS, Aix Marseille Université, Marseille 13402, France
| | - Silke Leimkühler
- University of Potsdam, Molecular Enzymology, Potsdam 14476, Germany
| | - Shun Hirota
- Nara Institute of Science and Technology, Division of Materials Science, Graduate School of Science and Technology, Nara 630-0192, Japan
| | - Yilin Hu
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States
| | - Andrew Jasniewski
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States
| | - Hideaki Ogata
- Nara Institute of Science and Technology, Division of Materials Science, Graduate School of Science and Technology, Nara 630-0192, Japan.,Hokkaido University, Institute of Low Temperature Science, Sapporo 060-0819, Japan.,Graduate School of Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Markus W Ribbe
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States.,Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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5
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Abstract
[FeFe]-hydrogenases are efficient H2-catalysts, yet upon contact with dioxygen their catalytic cofactor (H-cluster) is irreversibly inactivated. Here, we combine X-ray crystallography, rational protein design, direct electrochemistry, and Fourier-transform infrared spectroscopy to describe a protein morphing mechanism that controls the reversible transition between the catalytic Hox-state and the inactive but oxygen-resistant Hinact-state in [FeFe]-hydrogenase CbA5H of Clostridium beijerinckii. The X-ray structure of air-exposed CbA5H reveals that a conserved cysteine residue in the local environment of the active site (H-cluster) directly coordinates the substrate-binding site, providing a safety cap that prevents O2-binding and consequently, cofactor degradation. This protection mechanism depends on three non-conserved amino acids situated approximately 13 Å away from the H-cluster, demonstrating that the 1st coordination sphere chemistry of the H-cluster can be remote-controlled by distant residues.
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6
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Stripp ST, Mebs S, Haumann M. Temperature Dependence of Structural Dynamics at the Catalytic Cofactor of [FeFe]-hydrogenase. Inorg Chem 2020; 59:16474-16488. [PMID: 33147959 DOI: 10.1021/acs.inorgchem.0c02316] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
[FeFe]-hydrogenases are nature's blueprint for efficient hydrogen turnover. Understanding their enzymatic mechanism may improve technological H2 fuel generation. The active-site cofactor (H-cluster) consists of a [4Fe-4S] cluster ([4Fe]H), cysteine-linked to a diiron site ([2Fe]H) carrying an azadithiolate (adt) group, terminal cyanide and carbon monoxide ligands, and a bridging carbon monoxide (μCO) in the oxidized protein (Hox). Recently, the debate on the structure of reduced H-cluster states was intensified by the assignment of new species under cryogenic conditions. We investigated temperature effects (4-280 K) in infrared (IR) and X-ray absorption spectroscopy (XAS) data of [FeFe]-hydrogenases using fit analyses and quantum-chemical calculations. IR data from our laboratory and literature sources were evaluated. At ambient temperatures, reduced H-cluster states with a bridging hydride (μH-, in Hred and Hsred) or with an additional proton at [4Fe]H (Hred') or at the distal iron of [2Fe]H (Hhyd) prevail. At cryogenic temperatures, these species are largely replaced by states that hold a μCO, lack [4Fe]H protonation, and bind an additional proton at the adt nitrogen (HredH+ and HsredH+). XAS revealed the atomic coordinate dispersion (i.e., the Debye-Waller parameter, 2σ2) of the iron-ligand bonds and Fe-Fe distances in the oxidized and reduced H-cluster. 2σ2 showed a temperature dependence typical for the so-called protein-glass transition, with small changes below ∼200 K and a pronounced increase above this "breakpoint". This behavior is attributed to the freezing-out of larger-scale anharmonic motions of amino acid side chains and water species. We propose that protonation at [4Fe]H as well as ligand rearrangement and μH- binding at [2Fe]H are impaired because of restricted molecular mobility at cryogenic temperatures so that protonation can be biased toward adt. We conclude that a H-cluster with a μCO, selective [4Fe]H or [2Fe]H protonation, and catalytic proton transfer via adt facilitates efficient H2 conversion in [FeFe]-hydrogenase.
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Affiliation(s)
- Sven T Stripp
- Physics Department, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
| | - Stefan Mebs
- Physics Department, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
| | - Michael Haumann
- Physics Department, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
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7
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Fan Q, Neubauer P, Lenz O, Gimpel M. Heterologous Hydrogenase Overproduction Systems for Biotechnology-An Overview. Int J Mol Sci 2020; 21:E5890. [PMID: 32824336 PMCID: PMC7460606 DOI: 10.3390/ijms21165890] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/06/2020] [Accepted: 08/14/2020] [Indexed: 01/16/2023] Open
Abstract
Hydrogenases are complex metalloenzymes, showing tremendous potential as H2-converting redox catalysts for application in light-driven H2 production, enzymatic fuel cells and H2-driven cofactor regeneration. They catalyze the reversible oxidation of hydrogen into protons and electrons. The apo-enzymes are not active unless they are modified by a complicated post-translational maturation process that is responsible for the assembly and incorporation of the complex metal center. The catalytic center is usually easily inactivated by oxidation, and the separation and purification of the active protein is challenging. The understanding of the catalytic mechanisms progresses slowly, since the purification of the enzymes from their native hosts is often difficult, and in some case impossible. Over the past decades, only a limited number of studies report the homologous or heterologous production of high yields of hydrogenase. In this review, we emphasize recent discoveries that have greatly improved our understanding of microbial hydrogenases. We compare various heterologous hydrogenase production systems as well as in vitro hydrogenase maturation systems and discuss their perspectives for enhanced biohydrogen production. Additionally, activities of hydrogenases isolated from either recombinant organisms or in vivo/in vitro maturation approaches were systematically compared, and future perspectives for this research area are discussed.
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Affiliation(s)
- Qin Fan
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
| | - Peter Neubauer
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
| | - Oliver Lenz
- Department of Chemistry, Technical University of Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
| | - Matthias Gimpel
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
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8
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Németh B, Land H, Magnuson A, Hofer A, Berggren G. The maturase HydF enables [FeFe] hydrogenase assembly via transient, cofactor-dependent interactions. J Biol Chem 2020; 295:11891-11901. [PMID: 32620553 PMCID: PMC7450098 DOI: 10.1074/jbc.ra119.011419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 06/25/2020] [Indexed: 12/24/2022] Open
Abstract
[FeFe] hydrogenases have attracted extensive attention in the field of renewable energy research because of their remarkable efficiency for H2 gas production. H2 formation is catalyzed by a biologically unique hexanuclear iron cofactor denoted the H-cluster. The assembly of this cofactor requires a dedicated maturation machinery including HydF, a multidomain [4Fe4S] cluster protein with GTPase activity. HydF is responsible for harboring and delivering a precatalyst to the apo-hydrogenase, but the details of this process are not well understood. Here, we utilize gas-phase electrophoretic macromolecule analysis to show that a HydF dimer forms a transient interaction complex with the hydrogenase and that the formation of this complex depends on the cofactor content on HydF. Moreover, Fourier transform infrared, electron paramagnetic resonance, and UV-visible spectroscopy studies of mutants of HydF show that the isolated iron-sulfur cluster domain retains the capacity for binding the precatalyst in a reversible fashion and is capable of activating apo-hydrogenase in in vitro assays. These results demonstrate the central role of the iron-sulfur cluster domain of HydF in the final stages of H-cluster assembly, i.e. in binding and delivering the precatalyst.
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Affiliation(s)
- Brigitta Németh
- Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Henrik Land
- Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Ann Magnuson
- Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Gustav Berggren
- Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
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9
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The roles of long-range proton-coupled electron transfer in the directionality and efficiency of [FeFe]-hydrogenases. Proc Natl Acad Sci U S A 2020; 117:20520-20529. [PMID: 32796105 DOI: 10.1073/pnas.2007090117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
As paradigms for proton-coupled electron transfer in enzymes and benchmarks for a fully renewable H2 technology, [FeFe]-hydrogenases behave as highly reversible electrocatalysts when immobilized on an electrode, operating in both catalytic directions with minimal overpotential requirement. Using the [FeFe]-hydrogenases from Clostridium pasteurianum (CpI) and Chlamydomonas reinhardtii (CrHydA1) we have conducted site-directed mutagenesis and protein film electrochemistry to determine how efficient catalysis depends on the long-range coupling of electron and proton transfer steps. Importantly, the electron and proton transfer pathways in [FeFe]-hydrogenases are well separated from each other in space. Variants with conservative substitutions (glutamate to aspartate) in either of two positions in the proton-transfer pathway retain significant activity and reveal the consequences of slowing down proton transfer for both catalytic directions over a wide range of pH and potential values. Proton reduction in the variants is impaired mainly by limiting the turnover rate, which drops sharply as the pH is raised, showing that proton capture from bulk solvent becomes critical. In contrast, hydrogen oxidation is affected in two ways: by limiting the turnover rate and by a large overpotential requirement that increases as the pH is raised, consistent with the accumulation of a reduced and protonated intermediate. A unique observation having fundamental significance is made under conditions where the variants still retain sufficient catalytic activity in both directions: An inflection appears as the catalytic current switches direction at the 2H+/H2 thermodynamic potential, clearly signaling a departure from electrocatalytic reversibility as electron and proton transfers begin to be decoupled.
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10
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Németh B, Senger M, Redman HJ, Ceccaldi P, Broderick J, Magnuson A, Stripp ST, Haumann M, Berggren G. [FeFe]-hydrogenase maturation: H-cluster assembly intermediates tracked by electron paramagnetic resonance, infrared, and X-ray absorption spectroscopy. J Biol Inorg Chem 2020; 25:777-788. [PMID: 32661785 PMCID: PMC7399679 DOI: 10.1007/s00775-020-01799-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/09/2020] [Indexed: 11/25/2022]
Abstract
[FeFe]-hydrogenase enzymes employ a unique organometallic cofactor for efficient and reversible hydrogen conversion. This so-called H-cluster consists of a [4Fe-4S] cubane cysteine linked to a diiron complex coordinated by carbon monoxide and cyanide ligands and an azadithiolate ligand (adt = NH(CH2S)2)·[FeFe]-hydrogenase apo-protein binding only the [4Fe-4S] sub-complex can be fully activated in vitro by the addition of a synthetic diiron site precursor complex ([2Fe]adt). Elucidation of the mechanism of cofactor assembly will aid in the design of improved hydrogen processing synthetic catalysts. We combined electron paramagnetic resonance, Fourier-transform infrared, and X-ray absorption spectroscopy to characterize intermediates of H-cluster assembly as initiated by mixing of the apo-protein (HydA1) from the green alga Chlamydomonas reinhardtii with [2Fe]adt. The three methods consistently show rapid formation of a complete H-cluster in the oxidized, CO-inhibited state (Hox-CO) already within seconds after the mixing. Moreover, FTIR spectroscopy support a model in which Hox-CO formation is preceded by a short-lived Hred'-CO-like intermediate. Accumulation of Hox-CO was followed by CO release resulting in the slower conversion to the catalytically active state (Hox) as well as formation of reduced states of the H-cluster.
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Affiliation(s)
- Brigitta Németh
- Department of Chemistry, Ångström Laboratory, Molecular Biomimetics, Uppsala University, 75120, Uppsala, Sweden
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA
| | - Moritz Senger
- Physics Department, Molecular Biophysics, Freie Universität Berlin, 14195, Berlin, Germany
- Department of Chemistry, Ångström Laboratory, Physical Chemistry, Uppsala University, 75120, Uppsala, Sweden
| | - Holly J Redman
- Department of Chemistry, Ångström Laboratory, Molecular Biomimetics, Uppsala University, 75120, Uppsala, Sweden
| | - Pierre Ceccaldi
- Department of Chemistry, Ångström Laboratory, Molecular Biomimetics, Uppsala University, 75120, Uppsala, Sweden
| | - Joan Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA
| | - Ann Magnuson
- Department of Chemistry, Ångström Laboratory, Molecular Biomimetics, Uppsala University, 75120, Uppsala, Sweden
| | - Sven T Stripp
- Physics Department, Molecular Biophysics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Michael Haumann
- Physics Department, Biophysics of Metalloenzymes, Freie Universität Berlin, 14195, Berlin, Germany
| | - Gustav Berggren
- Department of Chemistry, Ångström Laboratory, Molecular Biomimetics, Uppsala University, 75120, Uppsala, Sweden.
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11
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Corrigan PS, Tirsch JL, Silakov A. Investigation of the Unusual Ability of the [FeFe] Hydrogenase from Clostridium beijerinckii to Access an O 2-Protected State. J Am Chem Soc 2020; 142:12409-12419. [PMID: 32580545 DOI: 10.1021/jacs.0c04964] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[FeFe] hydrogenases are enzymes capable of producing and oxidizing H2 at staggering submillisecond time scales. A major limitation in applying these enzymes for industrial hydrogen production is their irreversible inactivation by oxygen. Recently, an [FeFe] hydrogenase from Clostridium beijerinckii (CbHydA1) was reported to regain its catalytic activity after exposure to oxygen. In this report, we have determined that artificially matured CbHydA1 is indeed oxygen tolerant in the absence of reducing agents and sulfides by means of reaching an O2-protected state (Hinact). We were also able to generate the Hinact state anaerobically via both chemical and electrochemical oxidation. We use a combination of spectroscopy, electrochemistry, and density functional theory (DFT) to uncover intrinsic properties of the active center of CbHydA1, leading to its unprecedented oxygen tolerance. We have observed that reversible, low-potential oxidation of the active center leads to the protection against O2-induced degradation. The transition between the active oxidized state (Hox) and the Hinact state appears to proceed without any detectable intermediates. We found that the Hinact state is stable for more than 40 h in air, highlighting the remarkable resilience of CbHydA1 to oxygen. Using a combination of DFT and FTIR, we also provide a hypothesis for the chemical identity of the Hinact state. These results demonstrate that CbHydA1 has remarkable stability in the presence of oxygen, which will drive future efforts to engineer more robust catalysts for biofuel production.
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Affiliation(s)
- Patrick S Corrigan
- The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Jonathan L Tirsch
- The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Alexey Silakov
- The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
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12
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Shan C, Yao S, Driess M. Where silylene–silicon centres matter in the activation of small molecules. Chem Soc Rev 2020; 49:6733-6754. [DOI: 10.1039/d0cs00815j] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Small molecules such as H2, N2, CO, NH3, O2 are ubiquitous stable species and their activation and role in the formation of value-added products are of fundamental importance in nature and industry.
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Affiliation(s)
- Changkai Shan
- Department of Chemistry
- Metalorganics and Inorganic Materials
- Technische Universität Berlin
- 10623 Berlin
- Germany
| | - Shenglai Yao
- Department of Chemistry
- Metalorganics and Inorganic Materials
- Technische Universität Berlin
- 10623 Berlin
- Germany
| | - Matthias Driess
- Department of Chemistry
- Metalorganics and Inorganic Materials
- Technische Universität Berlin
- 10623 Berlin
- Germany
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