1
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Liu YC, Chu KT, Wang HR, Lee GH, Tseng MC, Wang CH, Horng YC, Chiang MH. Chloride- and Hydrosulfide-Bound 2Fe Complexes as Models of the Oxygen-Stable State of [FeFe] Hydrogenase. Angew Chem Int Ed Engl 2024; 63:e202408142. [PMID: 38818643 DOI: 10.1002/anie.202408142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/01/2024]
Abstract
[FeFe] hydrogenases demonstrate remarkable catalytic efficiency in hydrogen evolution and oxidation processes. However, susceptibility of these enzymes to oxygen-induced degradation impedes their practical deployment in hydrogen-production devices and fuel cells. Recent investigations into the oxygen-stable (Hinact) state of the H-cluster revealed its inherent capacity to resist oxygen degradation. Herein, we present findings on Cl- and SH-bound [2Fe-2S] complexes, bearing relevance to the oxygen-stable state within a biological context. A characteristic attribute of these complexes is the terminal Cl-/SH- ligation to the iron center bearing the CO bridge. Structural analysis of the t-Cl demonstrates a striking resemblance to the Hinact state of DdHydAB and CbA5H. The t-Cl/t-SH exhibit reversible oxidation, with both redox species, electronically, being the first biomimetic analogs to the Htrans and Hinact states. These complexes exhibit notable resistance against oxygen-induced decomposition, supporting the potential oxygen-resistant nature of the Htrans and Hinact states. The swift reductive release of the Cl-/SH-group demonstrates its labile and kinetically controlled binding. The findings garnered from these investigations offer valuable insights into properties of the enzymatic O2-stable state, and key factors governing deactivation and reactivation conversion. This work contributes to the advancement of bio-inspired molecular catalysts and the integration of enzymes and artificial catalysts into H2-evolution devices and fuel-cell applications.
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Affiliation(s)
- Yu-Chiao Liu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Kai-Ti Chu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Hong-Ru Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Gene-Hsiang Lee
- Instrumentation Center, National Taiwan University, Taipei, 106, Taiwan
| | - Mei-Chun Tseng
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Cheng-Hsin Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Yih-Chern Horng
- Department of Chemistry, National Changhua University of Education, Changhua, 500, Taiwan
| | - Ming-Hsi Chiang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 115, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
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2
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Corrigan PS, Majer SH, Silakov A. Evidence of Atypical Structural Flexibility of the Active Site Surrounding of an [FeFe] Hydrogenase from Clostridium beijerinkii. J Am Chem Soc 2023; 145:11033-11044. [PMID: 37163727 DOI: 10.1021/jacs.2c13458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
[FeFe] hydrogenase from Clostridium beijerinkii (CbHydA1) is an unusual hydrogenase in that it can withstand prolonged exposure to O2 by reversibly converting into an O2-protected, inactive state (Hinact). It has been indicated in the past that an atypical conformation of the "SC367CP" loop near the [2Fe]H portion of the six-iron active site (H-cluster) allows the Cys367 residue to adopt an "off-H+-pathway" orientation, promoting a facile transition of the cofactor to Hinact. Here, we investigated the electronic structure of the H-cluster in the oxidized state (Hox) that directly converts to Hinact under oxidizing conditions and the related CO-inhibited state (Hox-CO). We demonstrate that both states exhibit two distinct forms in electron paramagnetic resonance (EPR) spectroscopy. The ratio between the two forms is pH-dependent but also sensitive to the buffer choice. Our IR and EPR analyses illustrate that the spectral heterogeneity is due to a perturbation of the coordination environment of the H-cluster's [4Fe4S]H subcluster without affecting the [2Fe]H subcluster. Overall, we conclude that the observation of two spectral components per state is evidence of heterogeneity of the environment of the H-cluster likely associated with conformational mobility of the SCCP loop. Such flexibility may allow Cys367 to switch rapidly between off- and on-H+-pathway rotamers. Consequently, we believe such structural mobility may be the key to maintaining high enzymatic activity while allowing a facile transition to the O2-protected state.
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Affiliation(s)
- Patrick S Corrigan
- Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Sean H Majer
- Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Alexey Silakov
- Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
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3
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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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4
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Duan J, Hemschemeier A, Burr DJ, Stripp ST, Hofmann E, Happe T. Cyanide Binding to [FeFe]-Hydrogenase Stabilizes the Alternative Configuration of the Proton Transfer Pathway. Angew Chem Int Ed Engl 2023; 62:e202216903. [PMID: 36464641 PMCID: PMC10107461 DOI: 10.1002/anie.202216903] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
Hydrogenases are H2 converting enzymes that harbor catalytic cofactors in which iron (Fe) ions are coordinated by biologically unusual carbon monoxide (CO) and cyanide (CN- ) ligands. Extrinsic CO and CN- , however, inhibit hydrogenases. The mechanism by which CN- binds to [FeFe]-hydrogenases is not known. Here, we obtained crystal structures of the CN- -treated [FeFe]-hydrogenase CpI from Clostridium pasteurianum. The high resolution of 1.39 Å allowed us to distinguish intrinsic CN- and CO ligands and to show that extrinsic CN- binds to the open coordination site of the cofactor where CO is known to bind. In contrast to other inhibitors, CN- treated crystals show conformational changes of conserved residues within the proton transfer pathway which could allow a direct proton transfer between E279 and S319. This configuration has been proposed to be vital for efficient proton transfer, but has never been observed structurally.
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Affiliation(s)
- Jifu Duan
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Anja Hemschemeier
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - David J Burr
- Department of Physics, Experimental Biophysics and Space Sciences, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Sven T Stripp
- Department of Biophysics, Experimental Molecular Biophysics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Eckhard Hofmann
- Department of Biophysics, Faculty of Biology and Biotechnology, Protein Crystallography, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Thomas Happe
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
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5
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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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6
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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: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [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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7
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Heghmanns M, Rutz A, Kutin Y, Engelbrecht V, Winkler M, Happe T, Kasanmascheff M. The oxygen-resistant [FeFe]-hydrogenase CbA5H harbors an unknown radical signal. Chem Sci 2022; 13:7289-7294. [PMID: 35799827 PMCID: PMC9214887 DOI: 10.1039/d2sc00385f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/28/2022] [Indexed: 11/21/2022] Open
Abstract
[FeFe]-hydrogenases catalyze the reversible conversion of molecular hydrogen into protons and electrons with remarkable efficiency. However, their industrial applications are limited by their oxygen sensitivity. Recently, it was shown that the [FeFe]-hydrogenase from Clostridium beijerinckii (CbA5H) is oxygen-resistant and can be reactivated after oxygen exposure. In this work, we used multifrequency continuous wave and pulsed electron paramagnetic resonance (EPR) spectroscopy to characterize the active center of CbA5H, the H-cluster. Under oxidizing conditions, the spectra were dominated by an additional and unprecedented radical species. The generation of this radical signal depends on the presence of an intact H-cluster and a complete proton transfer pathway including the bridging azadithiolate ligand. Selective 57Fe enrichment combined with isotope-sensitive electron-nuclear double resonance (ENDOR) spectroscopy revealed a spin density distribution that resembles an H-cluster state. Overall, we uncovered a radical species in CbA5H that is potentially involved in the redox sensing of CbA5H. Electron paramagnetic resonance spectroscopy revealed an unprecedented radical species in the oxygen-resistant [FeFe]-hydrogenase CbA5H. Analysis of the isotope-sensitive data suggests that it is related to the active site, the H-cluster.![]()
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Affiliation(s)
- Melanie Heghmanns
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Straße 6, 44227 Dortmund, Germany
| | - Andreas Rutz
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Universitätsstr. 150, 44801 Bochum, Germany
| | - Yury Kutin
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Straße 6, 44227 Dortmund, Germany
| | - Vera Engelbrecht
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Universitätsstr. 150, 44801 Bochum, Germany
| | - Martin Winkler
- Technical University of Munich Campus Straubing for Biotechnology and Sustainability, Professorship for Electrobiotechnology, Uferstrasse 53, 94315 Straubing, Germany
| | - Thomas Happe
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Universitätsstr. 150, 44801 Bochum, Germany
| | - Müge Kasanmascheff
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Straße 6, 44227 Dortmund, Germany
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8
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Patel A, Mulder DW, Söll D, Krahn N. Harnessing selenocysteine to enhance microbial cell factories for hydrogen production. FRONTIERS IN CATALYSIS 2022; 2. [PMID: 36844461 PMCID: PMC9961374 DOI: 10.3389/fctls.2022.1089176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hydrogen is a clean, renewable energy source, that when combined with oxygen, produces heat and electricity with only water vapor as a biproduct. Furthermore, it has the highest energy content by weight of all known fuels. As a result, various strategies have engineered methods to produce hydrogen efficiently and in quantities that are of interest to the economy. To approach the notion of producing hydrogen from a biological perspective, we take our attention to hydrogenases which are naturally produced in microbes. These organisms have the machinery to produce hydrogen, which when cleverly engineered, could be useful in cell factories resulting in large production of hydrogen. Not all hydrogenases are efficient at hydrogen production, and those that are, tend to be oxygen sensitive. Therefore, we provide a new perspective on introducing selenocysteine, a highly reactive proteinogenic amino acid, as a strategy towards engineering hydrogenases with enhanced hydrogen production, or increased oxygen tolerance.
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Affiliation(s)
- Armaan Patel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - David W Mulder
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO, United States
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States.,Department of Chemistry, Yale University, New Haven, CT, United States
| | - Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
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9
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Birrell JA, Rodríguez-Maciá P, Reijerse EJ, Martini MA, Lubitz W. The catalytic cycle of [FeFe] hydrogenase: A tale of two sites. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214191] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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10
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Castner AT, Johnson BA, Cohen SM, Ott S. Mimicking the Electron Transport Chain and Active Site of [FeFe] Hydrogenases in One Metal-Organic Framework: Factors That Influence Charge Transport. J Am Chem Soc 2021; 143:7991-7999. [PMID: 34029060 PMCID: PMC8176456 DOI: 10.1021/jacs.1c01361] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
[FeFe] hydrogenase
(H2ase) enzymes are effective proton
reduction catalysts capable of forming molecular dihydrogen with a
high turnover frequency at low overpotential. The active sites of
these enzymes are buried within the protein structures, and substrates
required for hydrogen evolution (both protons and electrons) are shuttled
to the active sites through channels from the protein surface. Metal–organic
frameworks (MOFs) provide a unique platform for mimicking such enzymes
due to their inherent porosity which permits substrate diffusion and
their structural tunability which allows for the incorporation of
multiple functional linkers. Herein, we describe the preparation and
characterization of a redox-active PCN-700-based MOF (PCN = porous
coordination network) that features both a biomimetic model of the
[FeFe] H2ase active site as well as a redox-active linker
that acts as an electron mediator, thereby mimicking the function
of [4Fe4S] clusters in the enzyme. Rigorous studies on the dual-functionalized
MOF by cyclic voltammetry (CV) reveal similarities to the natural
system but also important limitations in the MOF-enzyme analogy. Most
importantly, and in contrast to the enzyme, restrictions apply to
the total concentration of reduced linkers and charge-balancing counter
cations that can be accommodated within the MOF. Successive charging
of the MOF results in nonideal interactions between linkers and restricted
mobility of charge-compensating redox-inactive counterions. Consequently,
apparent diffusion coefficients are no longer constant, and expected
redox features in the CVs of the materials are absent. Such nonlinear
effects may play an important role in MOFs for (electro)catalytic
applications.
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Affiliation(s)
- Ashleigh T Castner
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Ben A Johnson
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Seth M Cohen
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92023-0358, United States
| | - Sascha Ott
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
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11
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Kisgeropoulos EC, Manesis AC, Shafaat HS. Ligand Field Inversion as a Mechanism to Gate Bioorganometallic Reactivity: Investigating a Biochemical Model of Acetyl CoA Synthase Using Spectroscopy and Computation. J Am Chem Soc 2021; 143:849-867. [PMID: 33415980 DOI: 10.1021/jacs.0c10135] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The biological global carbon cycle is largely regulated through microbial nickel enzymes, including carbon monoxide dehydrogenase (CODH), acetyl coenzyme A synthase (ACS), and methyl coenzyme M reductase (MCR). These systems are suggested to utilize organometallic intermediates during catalysis, though characterization of these species has remained challenging. We have established a mutant of nickel-substituted azurin as a scaffold upon which to develop protein-based models of enzymatic intermediates, including the organometallic states of ACS. In this work, we report the comprehensive investigation of the S = 1/2 Ni-CO and Ni-CH3 states using pulsed EPR spectroscopy and computational techniques. While the Ni-CO state shows conventional metal-ligand interactions and a classical ligand field, the Ni-CH3 hyperfine interactions between the methyl protons and the nickel indicate a closer distance than would be expected for an anionic methyl ligand. Structural analysis instead suggests a near-planar methyl ligand that can be best described as cationic. Consistent with this conclusion, the frontier molecular orbitals of the Ni-CH3 species indicate a ligand-centered LUMO, with a d9 population on the metal center, rather than the d7 population expected for a typical metal-alkyl species generated by oxidative addition. Collectively, these data support the presence of an inverted ligand field configuration for the Ni-CH3 Az species, in which the lowest unoccupied orbital is centered on the ligands rather than the more electropositive metal. These analyses provide the first evidence for an inverted ligand field within a biological system. The functional relevance of the electronic structures of both the Ni-CO and Ni-CH3 species are discussed in the context of native ACS, and an inverted ligand field is proposed as a mechanism by which to gate reactivity both within ACS and in other thiolate-containing metalloenzymes.
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Affiliation(s)
- Effie C Kisgeropoulos
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Anastasia C Manesis
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Hannah S Shafaat
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
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12
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Kleinhaus JT, Wittkamp F, Yadav S, Siegmund D, Apfel UP. [FeFe]-Hydrogenases: maturation and reactivity of enzymatic systems and overview of biomimetic models. Chem Soc Rev 2021; 50:1668-1784. [DOI: 10.1039/d0cs01089h] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
[FeFe]-hydrogenases recieved increasing interest in the last decades. This review summarises important findings regarding their enzymatic reactivity as well as inorganic models applied as electro- and photochemical catalysts.
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Affiliation(s)
| | | | - Shanika Yadav
- Inorganic Chemistry I
- Ruhr University Bochum
- 44801 Bochum
- Germany
| | - Daniel Siegmund
- Department of Electrosynthesis
- Fraunhofer UMSICHT
- 46047 Oberhausen
- Germany
| | - Ulf-Peter Apfel
- Inorganic Chemistry I
- Ruhr University Bochum
- 44801 Bochum
- Germany
- Department of Electrosynthesis
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13
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Šimėnas M, O'Sullivan J, Zollitsch CW, Kennedy O, Seif-Eddine M, Ritsch I, Hülsmann M, Qi M, Godt A, Roessler MM, Jeschke G, Morton JJL. A sensitivity leap for X-band EPR using a probehead with a cryogenic preamplifier. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 322:106876. [PMID: 33264732 DOI: 10.1016/j.jmr.2020.106876] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
Inspired by the considerable success of cryogenically cooled NMR cryoprobes, we present an upgraded X-band EPR probehead, equipped with a cryogenic low-noise preamplifier. Our setup suppresses source noise, can handle the high microwave powers typical in X-band pulsed EPR, and is compatible with the convenient resonator coupling and sample access found on commercially available spectrometers. Our approach allows standard pulsed and continuous-wave EPR experiments to be performed at X-band frequency with significantly increased sensitivity compared to the unmodified setup. The probehead demonstrates a voltage signal-to-noise ratio (SNR) enhancement by a factor close to 8× at a temperature of 6 K, and remains close to 2× at room temperature. By further suppressing room-temperature noise at the expense of reduced microwave power (and thus minimum π-pulse length), the factor of SNR improvement approaches 15 at 6 K, corresponding to an impressive 200-fold reduction in EPR measurement time. We reveal the full potential of this probehead by demonstrating such SNR improvements using a suite of typical hyperfine and dipolar spectroscopy experiments on exemplary samples.
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Affiliation(s)
- Mantas Šimėnas
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK.
| | - James O'Sullivan
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | | | - Oscar Kennedy
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Maryam Seif-Eddine
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, London W12 0BZ, UK
| | - Irina Ritsch
- ETH Zürich, Department of Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Miriam Hülsmann
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany
| | - Mian Qi
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany
| | - Maxie M Roessler
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, London W12 0BZ, UK
| | - Gunnar Jeschke
- ETH Zürich, Department of Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - John J L Morton
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; Department of Electronic & Electrical Engineering, UCL, London WC1E 7JE, UK.
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14
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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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15
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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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16
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Reijerse E, Birrell JA, Lubitz W. Spin Polarization Reveals the Coordination Geometry of the [FeFe] Hydrogenase Active Site in Its CO-Inhibited State. J Phys Chem Lett 2020; 11:4597-4602. [PMID: 32420744 PMCID: PMC7309315 DOI: 10.1021/acs.jpclett.0c01352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
The active site of [FeFe] hydrogenase features a binuclear iron cofactor Fe2ADT(CO)3(CN)2, where ADT represents the bridging ligand aza-propane-dithiolate. The terminal diatomic ligands all coordinate in a basal configuration, and one CO bridges the two irons leaving an open coordination site at which the hydrogen species and the competitive inhibitor CO bind. Externally supplied CO is expected to coordinate in an apical configuration. However, an alternative configuration has been proposed in which, due to ligand rotation, the CN- bound to the distal Fe becomes apical. Using selective 13C isotope labeling of the CN- and COext ligands in combination with pulsed 13C electron-nuclear-nuclear triple resonance spectroscopy, spin polarization effects are revealed that, according to density functional theory calculations, are consistent with only the "unrotated" apical COext configuration.
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17
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Land H, Senger M, Berggren G, Stripp ST. Current State of [FeFe]-Hydrogenase Research: Biodiversity and Spectroscopic Investigations. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01614] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Henrik Land
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
| | - Moritz Senger
- Physical Chemistry, Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
- Bioinorganic Spectroscopy, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Gustav Berggren
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
| | - Sven T. Stripp
- Bioinorganic Spectroscopy, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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18
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Mészáros LS, Ceccaldi P, Lorenzi M, Redman HJ, Pfitzner E, Heberle J, Senger M, Stripp ST, Berggren G. Spectroscopic investigations under whole-cell conditions provide new insight into the metal hydride chemistry of [FeFe]-hydrogenase. Chem Sci 2020; 11:4608-4617. [PMID: 34122916 PMCID: PMC8159234 DOI: 10.1039/d0sc00512f] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Hydrogenases are among the fastest H2 evolving catalysts known to date and have been extensively studied under in vitro conditions. Here, we report the first mechanistic investigation of an [FeFe]-hydrogenase under whole-cell conditions. Functional [FeFe]-hydrogenase from the green alga Chlamydomonas reinhardtii is generated in genetically modified Escherichia coli cells by addition of a synthetic cofactor to the growth medium. The assembly and reactivity of the resulting semi-synthetic enzyme was monitored using whole-cell electron paramagnetic resonance and Fourier-transform Infrared difference spectroscopy as well as scattering scanning near-field optical microscopy. Through a combination of gas treatments, pH titrations, and isotope editing we were able to corroborate the formation of a number of proposed catalytic intermediates in living cells, supporting their physiological relevance. Moreover, a previously incompletely characterized catalytic intermediate is reported herein, attributed to the formation of a protonated metal hydride species.
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Affiliation(s)
- Lívia S Mészáros
- Molecular Biomimetics, Dept. of Chemistry - Ångström Laboratory, Uppsala University Lägerhyddsvägen 1 SE-75120 Uppsala Sweden
| | - Pierre Ceccaldi
- Molecular Biomimetics, Dept. of Chemistry - Ångström Laboratory, Uppsala University Lägerhyddsvägen 1 SE-75120 Uppsala Sweden
| | - Marco Lorenzi
- Molecular Biomimetics, Dept. of Chemistry - Ångström Laboratory, Uppsala University Lägerhyddsvägen 1 SE-75120 Uppsala Sweden
| | - Holly J Redman
- Molecular Biomimetics, Dept. of Chemistry - Ångström Laboratory, Uppsala University Lägerhyddsvägen 1 SE-75120 Uppsala Sweden
| | - Emanuel Pfitzner
- Institute of Experimental Physics, Experimental Molecular Biophysics, Freie Universität Berlin Arnimallee 14 Berlin DE-14195 Germany
| | - Joachim Heberle
- Institute of Experimental Physics, Experimental Molecular Biophysics, Freie Universität Berlin Arnimallee 14 Berlin DE-14195 Germany
| | - Moritz Senger
- Institute of Experimental Physics, Experimental Molecular Biophysics, Freie Universität Berlin Arnimallee 14 Berlin DE-14195 Germany
| | - Sven T Stripp
- Institute of Experimental Physics, Experimental Molecular Biophysics, Freie Universität Berlin Arnimallee 14 Berlin DE-14195 Germany
| | - Gustav Berggren
- Molecular Biomimetics, Dept. of Chemistry - Ångström Laboratory, Uppsala University Lägerhyddsvägen 1 SE-75120 Uppsala Sweden
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19
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Reijerse EJ, Pelmenschikov V, Birrell JA, Richers CP, Kaupp M, Rauchfuss TB, Cramer SP, Lubitz W. Asymmetry in the Ligand Coordination Sphere of the [FeFe] Hydrogenase Active Site Is Reflected in the Magnetic Spin Interactions of the Aza-propanedithiolate Ligand. J Phys Chem Lett 2019; 10:6794-6799. [PMID: 31580680 PMCID: PMC6844125 DOI: 10.1021/acs.jpclett.9b02354] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
[FeFe] hydrogenases are very active enzymes that catalyze the reversible conversion of molecular hydrogen into protons and electrons. Their active site, the H-cluster, contains a unique binuclear iron complex, [2Fe]H, with CN- and CO ligands as well as an aza-propane-dithiolate (ADT) moiety featuring a central amine functionality that mediates proton transfer during catalysis. We present a pulsed 13C-ENDOR investigation of the H-cluster in which the two methylene carbons of ADT are isotope labeled with 13C. We observed that the corresponding two 13C hyperfine interactions are of opposite sign and corroborated this finding using density functional theory calculations. The spin polarization in the ADT ligand is shown to be linked to the asymmetric coordination of the distal iron site with its terminal CN- and CO ligands. We propose that this asymmetry is relevant for the enzyme reactivity and is related to the (optimal) stabilization of the iron-hydride intermediate in the catalytic cycle.
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Affiliation(s)
- Edward J. Reijerse
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Vladimir Pelmenschikov
- Institut
für Chemie, Technische Universität
Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - James A. Birrell
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Casseday P. Richers
- School
of Chemical Sciences, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Martin Kaupp
- Institut
für Chemie, Technische Universität
Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Thomas B. Rauchfuss
- School
of Chemical Sciences, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | | | - Wolfgang Lubitz
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
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20
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Senger M, Eichmann V, Laun K, Duan J, Wittkamp F, Knör G, Apfel UP, Happe T, Winkler M, Heberle J, Stripp ST. How [FeFe]-Hydrogenase Facilitates Bidirectional Proton Transfer. J Am Chem Soc 2019; 141:17394-17403. [PMID: 31580662 PMCID: PMC6823627 DOI: 10.1021/jacs.9b09225] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Hydrogenases are metalloenzymes that
catalyze the conversion of
protons and molecular hydrogen, H2. [FeFe]-hydrogenases
show particularly high rates of hydrogen turnover and have inspired
numerous compounds for biomimetic H2 production. Two decades
of research on the active site cofactor of [FeFe]-hydrogenases have
put forward multiple models of the catalytic proceedings. In comparison,
our understanding of proton transfer is poor. Previously, residues
were identified forming a hydrogen-bonding network between active
site cofactor and bulk solvent; however, the exact mechanism of catalytic
proton transfer remained inconclusive. Here, we employ in
situ infrared difference spectroscopy on the [FeFe]-hydrogenase
from Chlamydomonas reinhardtii evaluating dynamic
changes in the hydrogen-bonding network upon photoreduction. While
proton transfer appears to be impaired in the oxidized state (Hox), the presented data support continuous proton transfer
in the reduced state (Hred). Our analysis allows for
a direct, molecular unique assignment to individual amino acid residues.
We found that transient protonation changes of glutamic acid residue
E141 and, most notably, arginine R148 facilitate bidirectional proton
transfer in [FeFe]-hydrogenases.
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Affiliation(s)
- Moritz Senger
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Viktor Eichmann
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Konstantin Laun
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | | | | | - Günther Knör
- Institute of Inorganic Chemistry , Johannes Kepler Universität Linz , Altenberger Straße 69 , 4040 Linz , Austria
| | | | | | | | - Joachim Heberle
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Sven Timo Stripp
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
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21
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Duan J, Mebs S, Laun K, Wittkamp F, Heberle J, Happe T, Hofmann E, Apfel UP, Winkler M, Senger M, Haumann M, Stripp ST. Geometry of the Catalytic Active Site in [FeFe]-Hydrogenase Is Determined by Hydrogen Bonding and Proton Transfer. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02203] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jifu Duan
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Stefan Mebs
- Department of Physics, Biophysics of Metalloenzymes, Freie Universität Berlin, 14195 Berlin, Germany
| | - Konstantin Laun
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Florian Wittkamp
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry I, Ruhr University Bochum, 44801 Bochum, Germany
| | - Joachim Heberle
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Eckhard Hofmann
- Faculty of Biology and Biotechnology, Protein Crystallography, Ruhr University Bochum, 44801 Bochum, Germany
| | - Ulf-Peter Apfel
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry I, Ruhr University Bochum, 44801 Bochum, Germany
- Fraunhofer UMSICHT, 46047 Oberhausen, Germany
| | - Martin Winkler
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Moritz Senger
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Michael Haumann
- Department of Physics, Biophysics of Metalloenzymes, Freie Universität Berlin, 14195 Berlin, Germany
| | - Sven T. Stripp
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
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22
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Abstract
The active site (H-cluster) of [FeFe]-hydrogenases is a blueprint for the design of a biologically inspired H2-producing catalyst. The maturation process describes the preassembly and uptake of the unique [2FeH] cluster into apo-hydrogenase, which is to date not fully understood. In this study, we targeted individual amino acids by site-directed mutagenesis in the [FeFe]-hydrogenase CpI of Clostridium pasteurianum to reveal the final steps of H-cluster maturation occurring within apo-hydrogenase. We identified putative key positions for cofactor uptake and the subsequent structural reorganization that stabilizes the [2FeH] cofactor in its functional coordination sphere. Our results suggest that functional integration of the negatively charged [2FeH] precursor requires the positive charges and individual structural features of the 2 basic residues of arginine 449 and lysine 358, which mark the entrance and terminus of the maturation channel, respectively. The results obtained for 5 glycine-to-histidine exchange variants within a flexible loop region provide compelling evidence that the glycine residues function as hinge positions in the refolding process, which closes the secondary ligand sphere of the [2FeH] cofactor and the maturation channel. The conserved structural motifs investigated here shed light on the interplay between the secondary ligand sphere and catalytic cofactor.
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23
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Electrochemical and Computational Insights into the Reduction of [Fe2(CO)6{µ-(SCH2)2GeMe2}] Hydrogenase H-Cluster Mimic. INORGANICS 2019. [DOI: 10.3390/inorganics7040050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The electrochemical reduction of the complex [Fe2(CO)6{µ-(SCH2)2GeMe2}] (1) under N2 and CO is reported applying cyclic voltammetry. Reduction of complex 1 in CO saturated solutions prevents the possible release of CO from the dianion 12−, while the latter reacts with additional CO forming a spectroscopically uncharacterized product P1. This product undergoes a reversible redox process at E1/2 = −0.70 V (0.2 V∙s−1). In this report, the structure of the neutral complex 1, isomers of dianionic form of 1, and P1 are described applying DFT computations. Furthermore, we propose reaction pathways for H2 production on the basis of the cyclic voltammetry of complex 1 in presence of the strong acid CF3SO3H.
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24
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Mebs S, Duan J, Wittkamp F, Stripp ST, Happe T, Apfel UP, Winkler M, Haumann M. Differential Protonation at the Catalytic Six-Iron Cofactor of [FeFe]-Hydrogenases Revealed by 57Fe Nuclear Resonance X-ray Scattering and Quantum Mechanics/Molecular Mechanics Analyses. Inorg Chem 2019; 58:4000-4013. [PMID: 30802044 DOI: 10.1021/acs.inorgchem.9b00100] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[FeFe]-hydrogenases are efficient biological hydrogen conversion catalysts and blueprints for technological fuel production. The relations between substrate interactions and electron/proton transfer events at their unique six-iron cofactor (H-cluster) need to be elucidated. The H-cluster comprises a four-iron cluster, [4Fe4S], linked to a diiron complex, [FeFe]. We combined 57Fe-specific X-ray nuclear resonance scattering experiments (NFS, nuclear forward scattering; NRVS, nuclear resonance vibrational spectroscopy) with quantum-mechanics/molecular-mechanics computations to study the [FeFe]-hydrogenase HYDA1 from a green alga. Selective 57Fe labeling at only [4Fe4S] or [FeFe], or at both subcomplexes was achieved by protein expression with a 57Fe salt and in vitro maturation with a synthetic diiron site precursor containing 57Fe. H-cluster states were populated under infrared spectroscopy control. NRVS spectral analyses facilitated assignment of the vibrational modes of the cofactor species. This approach revealed the H-cluster structure of the oxidized state (Hox) with a bridging carbon monoxide at [FeFe] and ligand rearrangement in the CO-inhibited state (Hox-CO). Protonation at a cysteine ligand of [4Fe4S] in the oxidized state occurring at low pH (HoxH) was indicated, in contrast to bridging hydride binding at [FeFe] in a one-electron reduced state (Hred). These findings are direct evidence for differential protonation either at the four-iron or diiron subcomplex of the H-cluster. NFS time-traces provided Mössbauer parameters such as the quadrupole splitting energy, which differ among cofactor states, thereby supporting selective protonation at either subcomplex. In combination with data for reduced states showing similar [4Fe4S] protonation as HoxH without (Hred') or with (Hhyd) a terminal hydride at [FeFe], our results imply that coordination geometry dynamics at the diiron site and proton-coupled electron transfer to either the four-iron or the diiron subcomplex discriminate catalytic and regulatory functions of [FeFe]-hydrogenases. We support a reaction cycle avoiding diiron site geometry changes during rapid H2 turnover.
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Affiliation(s)
| | | | | | | | | | - Ulf-Peter Apfel
- Fraunhofer UMSICHT , Osterfelder Straße 3 , 46047 Oberhausen , Germany
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25
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Wili N, Richert S, Limburg B, Clarke SJ, Anderson HL, Timmel CR, Jeschke G. ELDOR-detected NMR beyond hyperfine couplings: a case study with Cu(ii)-porphyrin dimers. Phys Chem Chem Phys 2019; 21:11676-11688. [DOI: 10.1039/c9cp01760g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The pulse EPR method ELDOR-detected NMR gives information about electron–electron couplings in Cu(ii) porphyrin dimers.
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Affiliation(s)
- Nino Wili
- Laboratorium für Physikalische Chemie
- ETH Zürich
- 8093 Zürich
- Switzerland
| | - Sabine Richert
- Centre for Advanced Electron Spin Resonance (CÆSR)
- University of Oxford
- Oxford
- UK
| | - Bart Limburg
- Chemistry Research Laboratory
- University of Oxford
- Oxford
- UK
| | | | | | | | - Gunnar Jeschke
- Laboratorium für Physikalische Chemie
- ETH Zürich
- 8093 Zürich
- Switzerland
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26
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Rao G, Britt RD. Electronic Structure of Two Catalytic States of the [FeFe] Hydrogenase H-Cluster As Probed by Pulse Electron Paramagnetic Resonance Spectroscopy. Inorg Chem 2018; 57:10935-10944. [PMID: 30106575 DOI: 10.1021/acs.inorgchem.8b01557] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The active site of the [FeFe] hydrogenase (HydA1), the H-cluster, is a 6-Fe cofactor that contains CO and CN- ligands. It undergoes several different oxidation and protonation state changes in its catalytic cycle to metabolize H2. Among them, the well-known Hox state and the recently identified Hhyd state are thought to be directly involved in H2 activation and evolution, and they are both EPR active with net spin S = 1/2. Herein, we report the pulse electronic paramagnetic spectroscopic investigation of these two catalytic states in Chlamydomonas reinhardtii HydA1 ( CrHydA1). Using an in vitro biosynthetic maturation approach, we site-specifically installed 13C into the CO or CN- ligands and 57Fe into the [2Fe]H subcluster of the H-cluster in order to measure the hyperfine couplings to these magnetic nuclei. For Hox, we measured 13C hyperfine couplings (13CO aiso of 25.5, 5.8, and 4.5 MHz) corresponding to all three CO ligands in the H-cluster. We also observed two 57Fe hyperfine couplings (57Fe aiso of ∼17 and 5.7 MHz) arising from the two Fe atoms in the [2Fe]H subcluster. For Hhyd, we only observed two distinct 13CO hyperfine interactions (13CO aiso of 0.16 and 0.08 MHz) and only one for 13CN- (13CN aiso of 0.16 MHz); the couplings to the 13CO/13CN- on the distal Fe of [2Fe]H may be too small to detect. We also observed a very small (<0.3 MHz) 57Fe HFI from the labeled [2Fe]H subcluster and four 57Fe HFI from the labeled [4Fe-4S]H subcluster (57Fe aiso of 7.2, 16.6, 28.2, and 35.3 MHz). These hyperfine coupling constants are consistent with the previously proposed electronic structure of the H-cluster at both Hox and Hhyd states and provide a basis for more detailed analysis.
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Affiliation(s)
- Guodong Rao
- Department of Chemistry , University of California , Davis , California 95616 , United States
| | - R David Britt
- Department of Chemistry , University of California , Davis , California 95616 , United States
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27
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Scott AG, Szilagyi RK, Mulder DW, Ratzloff MW, Byer AS, King PW, Broderick WE, Shepard EM, Broderick JB. Compositional and structural insights into the nature of the H-cluster precursor on HydF. Dalton Trans 2018; 47:9521-9535. [PMID: 29964288 DOI: 10.1039/c8dt01654b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Assembly of an active [FeFe]-hydrogenase requires dedicated maturation enzymes that generate the active-site H-cluster: the radical SAM enzymes HydE and HydG synthesize the unusual non-protein ligands - carbon monoxide, cyanide, and dithiomethylamine - while the GTPase HydF serves as a scaffold for assembly of the 2Fe subcluster containing these ligands. In the current study, enzymatically cluster-loaded HydF ([2Fe]F) is produced by co-expression with HydE and HydG in an Escherichia coli host followed by isolation and examination by FTIR and EPR spectroscopy. FTIR reveals the presence of well-defined terminal CO and CN- ligands; however, unlike in the [FeFe]-hydrogenase, no bridging CO is observed. Exposure of this loaded HydF to exogenous CO or H2 produces no significant changes to the FTIR spectrum, indicating that, unlike in the [FeFe]-hydrogenase, the 2Fe cluster in loaded HydF is coordinatively saturated and relatively unreactive. EPR spectroscopy reveals the presence of both [4Fe-4S] and [2Fe-2S] clusters on this loaded HydF, but provides no direct evidence for these being linked to the [2Fe]F. Using the chemical reactivity and FTIR data, a large collection of computational models were evaluated. Their scaled quantum chemical vibrational spectra allowed us to score various [2Fe]F structures in terms of their ability to reproduce the diatomic stretching frequencies observed in the FTIR experimental spectra. Collectively, the results provide new insights that support the presence of a diamagnetic, but spin-polarized FeI-FeI oxidation state for the [2Fe]F precursor cluster that is coordinated by 4 CO and 2 CN- ligands, and bridged to an adjacent iron-sulfur cluster through one of the CN- ligands.
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Affiliation(s)
- Anna G Scott
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
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28
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Spectroscopical Investigations on the Redox Chemistry of [FeFe]-Hydrogenases in the Presence of Carbon Monoxide. Molecules 2018; 23:molecules23071669. [PMID: 29987246 PMCID: PMC6100070 DOI: 10.3390/molecules23071669] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/13/2022] Open
Abstract
[FeFe]-hydrogenases efficiently catalyzes hydrogen conversion at a unique [4Fe⁻4S]-[FeFe] cofactor, the so-called H-cluster. The catalytic reaction occurs at the diiron site, while the [4Fe⁻4S] cluster functions as a redox shuttle. In the oxidized resting state (Hox), the iron ions of the diiron site bind one cyanide (CN−) and carbon monoxide (CO) ligand each and a third carbonyl can be found in the Fe⁻Fe bridging position (µCO). In the presence of exogenous CO, A fourth CO ligand binds at the diiron site to form the oxidized, CO-inhibited H-cluster (Hox-CO). We investigated the reduced, CO-inhibited H-cluster (Hred´-CO) in this work. The stretching vibrations of the diatomic ligands were monitored by attenuated total reflection Fourier-transform infrared spectroscopy (ATR FTIR). Density functional theory (DFT) at the TPSSh/TZVP level was employed to analyze the cofactor geometry, as well as the redox and protonation state of the H-cluster. Selective 13CO isotope editing, spectro-electrochemistry, and correlation analysis of IR data identified a one-electron reduced, protonated [4Fe⁻4S] cluster and an apical CN− ligand at the diiron site in Hred´-CO. The reduced, CO-inhibited H-cluster forms independently of the sequence of CO binding and cofactor reduction, which implies that the ligand rearrangement at the diiron site upon CO inhibition is independent of the redox and protonation state of the [4Fe⁻4S] cluster. The relation of coordination dynamics to cofactor redox and protonation changes in hydrogen conversion catalysis and inhibition is discussed.
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29
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Del Barrio M, Sensi M, Fradale L, Bruschi M, Greco C, de Gioia L, Bertini L, Fourmond V, Léger C. Interaction of the H-Cluster of FeFe Hydrogenase with Halides. J Am Chem Soc 2018; 140:5485-5492. [PMID: 29590528 DOI: 10.1021/jacs.8b01414] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
FeFe hydrogenases catalyze H2 oxidation and production using an "H-cluster", where two Fe ions are bound by an aza-dithiolate (adt) ligand. Various hypotheses have been proposed (by us and others) to explain that the enzyme reversibly inactivates under oxidizing, anaerobic conditions: intramolecular binding of the N atom of adt, formation of the so-called "Hox/inact" state or nonproductive binding of H2 to isomers of the H-cluster. Here, we show that none of the above explains the new finding that the anaerobic, oxidative, H2-dependent reversible inactivation is strictly dependent on the presence of Cl- or Br-. We provide experimental evidence that chloride uncompetitively inhibits the enzyme: it reversibly binds to catalytic intermediates of H2 oxidation (but not to the resting "Hox" state), after which oxidation locks the active site into a stable, saturated, inactive form, the structure of which is proposed here based on DFT calculations. The halides interact with the amine group of the H-cluster but do not directly bind to iron. It should be possible to stabilize the inhibited state in amounts compatible with spectroscopic investigations to explore further this unexpected reactivity of the H-cluster of hydrogenase.
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Affiliation(s)
- Melisa Del Barrio
- Aix Marseille Université , CNRS, Bioénergétique et Ingénierie des Protéines , Marseille , France
| | - Matteo Sensi
- Aix Marseille Université , CNRS, Bioénergétique et Ingénierie des Protéines , Marseille , France
| | - Laura Fradale
- Aix Marseille Université , CNRS, Bioénergétique et Ingénierie des Protéines , Marseille , France
| | - Maurizio Bruschi
- Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 Milan , Italy
| | - Claudio Greco
- Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 Milan , Italy
| | - Luca de Gioia
- Department of Biotechnologies and Biosciences , University of Milano-Bicocca , 20126 Milan , Italy
| | - Luca Bertini
- Department of Biotechnologies and Biosciences , University of Milano-Bicocca , 20126 Milan , Italy
| | - Vincent Fourmond
- Aix Marseille Université , CNRS, Bioénergétique et Ingénierie des Protéines , Marseille , France
| | - Christophe Léger
- Aix Marseille Université , CNRS, Bioénergétique et Ingénierie des Protéines , Marseille , France
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30
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A [4Fe-4S]-Fe(CO)(CN)-L-cysteine intermediate is the first organometallic precursor in [FeFe] hydrogenase H-cluster bioassembly. Nat Chem 2018; 10:555-560. [PMID: 29632334 PMCID: PMC6380689 DOI: 10.1038/s41557-018-0026-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/14/2018] [Indexed: 12/27/2022]
Abstract
Biosynthesis of the [FeFe] hydrogenase active site (the 'H-cluster') requires the interplay of multiple proteins and small molecules. Among them, the radical S-adenosylmethionine enzyme HydG, a tyrosine lyase, has been proposed to generate a complex that contains an Fe(CO)2(CN) moiety that is eventually incorporated into the H-cluster. Here we describe the characterization of an intermediate in the HydG reaction: a [4Fe-4S][(Cys)Fe(CO)(CN)] species, 'Complex A', in which a CO, a CN- and a cysteine (Cys) molecule bind to the unique 'dangler' Fe site of the auxiliary [5Fe-4S] cluster of HydG. The identification of this intermediate-the first organometallic precursor to the H-cluster-validates the previously hypothesized HydG reaction cycle and provides a basis for elucidating the biosynthetic origin of other moieties of the H-cluster.
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31
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Esmieu C, Raleiras P, Berggren G. From protein engineering to artificial enzymes - biological and biomimetic approaches towards sustainable hydrogen production. SUSTAINABLE ENERGY & FUELS 2018; 2:724-750. [PMID: 31497651 PMCID: PMC6695573 DOI: 10.1039/c7se00582b] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/31/2018] [Indexed: 06/09/2023]
Abstract
Hydrogen gas is used extensively in industry today and is often put forward as a suitable energy carrier due its high energy density. Currently, the main source of molecular hydrogen is fossil fuels via steam reforming. Consequently, novel production methods are required to improve the sustainability of hydrogen gas for industrial processes, as well as paving the way for its implementation as a future solar fuel. Nature has already developed an elaborate hydrogen economy, where the production and consumption of hydrogen gas is catalysed by hydrogenase enzymes. In this review we summarize efforts on engineering and optimizing these enzymes for biological hydrogen gas production, with an emphasis on their inorganic cofactors. Moreover, we will describe how our understanding of these enzymes has been applied for the preparation of bio-inspired/-mimetic systems for efficient and sustainable hydrogen production.
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Affiliation(s)
- C Esmieu
- Department of Chemistry , Ångström Laboratory , Uppsala University , Box 523 , SE-75120 Uppsala , Sweden .
| | - P Raleiras
- Department of Chemistry , Ångström Laboratory , Uppsala University , Box 523 , SE-75120 Uppsala , Sweden .
| | - G Berggren
- Department of Chemistry , Ångström Laboratory , Uppsala University , Box 523 , SE-75120 Uppsala , Sweden .
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32
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Carlson MR, Gray DL, Richers CP, Wang W, Zhao PH, Rauchfuss TB, Pelmenschikov V, Pham CC, Gee LB, Wang H, Cramer SP. Sterically Stabilized Terminal Hydride of a Diiron Dithiolate. Inorg Chem 2018; 57:1988-2001. [PMID: 29384371 DOI: 10.1021/acs.inorgchem.7b02903] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The kinetically robust hydride [t-HFe2(Me2pdt)(CO)2(dppv)2]+ ([t-H1]+) (Me2pdt2- = Me2C(CH2S-)2; dppv = cis-1,2-C2H2(PPh2)2) and related derivatives were prepared with 57Fe enrichment for characterization by NMR, FT-IR, and NRVS. The experimental results were rationalized using DFT molecular modeling and spectral simulations. The spectroscopic analysis was aimed at supporting assignments of Fe-H vibrational spectra as they relate to recent measurements on [FeFe]-hydrogenase enzymes. The combination of bulky Me2pdt2- and dppv ligands stabilizes the terminal hydride with respect to its isomerization to the 5-16 kcal/mol more stable bridging hydride ([μ-H1]+) with t1/2(313.3 K) = 19.3 min. In agreement with the nOe experiments, the calculations predict that one methyl group in [t-H1]+ interacts with the hydride with a computed CH···HFe distance of 1.7 Å. Although [t-H571]+ exhibits multiple NRVS features in the 720-800 cm-1 region containing the bending Fe-H modes, the deuterated [t-D571]+ sample exhibits a unique Fe-D/CO band at ∼600 cm-1. In contrast, the NRVS spectra for [μ-H571]+ exhibit weaker bands near 670-700 cm-1 produced by the Fe-H-Fe wagging modes coupled to Me2pdt2- and dppv motions.
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Affiliation(s)
- Michaela R Carlson
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | - Danielle L Gray
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | - Casseday P Richers
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | - Wenguang Wang
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | - Pei-Hua Zhao
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois , Urbana, Illinois 61801, United States
| | | | - Cindy C Pham
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Leland B Gee
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Hongxin Wang
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Stephen P Cramer
- Department of Chemistry, University of California , Davis, California 95616, United States
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33
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Rumpel S, Ravera E, Sommer C, Reijerse E, Farès C, Luchinat C, Lubitz W. 1H NMR Spectroscopy of [FeFe] Hydrogenase: Insight into the Electronic Structure of the Active Site. J Am Chem Soc 2018; 140:131-134. [PMID: 29211457 PMCID: PMC5765528 DOI: 10.1021/jacs.7b11196] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The [FeFe] hydrogenase
HydA1 from Chlamydomonas reinhardtii has been studied
using 1H NMR spectroscopy identifying
the paramagnetically shifted 1H resonances associated with
both the [4Fe-4S]H and the
[2Fe]H subclusters of the active site “H-cluster”.
The signal pattern of the unmaturated HydA1 containing only [4Fe-4S]H is reminiscent of bacterial-type ferredoxins. The spectra
of maturated HydA1, with a complete H-cluster in the active Hox and the CO-inhibited Hox–CO state, reveal
additional upfield and downfield shifted 1H resonances
originating from the four methylene protons of the azadithiolate ligand
in the [2Fe]H subsite. The two axial protons are affected
by positive spin density, while the two equatorial protons experience
negative spin density. These protons can be used as important probes
sensing the effects of ligand-binding to the catalytic site of the
H-cluster.
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Affiliation(s)
- Sigrun Rumpel
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Enrico Ravera
- Department of Chemistry "Ugo Schiff" and Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP) , Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Constanze Sommer
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Edward Reijerse
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Christophe Farès
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Claudio Luchinat
- Department of Chemistry "Ugo Schiff" and Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP) , Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
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34
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Mebs S, Kositzki R, Duan J, Kertess L, Senger M, Wittkamp F, Apfel UP, Happe T, Stripp ST, Winkler M, Haumann M. Hydrogen and oxygen trapping at the H-cluster of [FeFe]-hydrogenase revealed by site-selective spectroscopy and QM/MM calculations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:28-41. [DOI: 10.1016/j.bbabio.2017.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/31/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022]
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35
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Wittkamp F, Senger M, Stripp ST, Apfel UP. [FeFe]-Hydrogenases: recent developments and future perspectives. Chem Commun (Camb) 2018; 54:5934-5942. [DOI: 10.1039/c8cc01275j] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
[FeFe]-Hydrogenases are the most efficient enzymes for catalytic hydrogen turnover.
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Affiliation(s)
- F. Wittkamp
- Faculty of Chemistry and Biochemistry
- Ruhr-Universität Bochum
- 44801 Bochum
- Germany
| | - M. Senger
- Department of Physics
- Freie Universität Berlin
- 1495 Berlin
- Germany
| | - S. T. Stripp
- Department of Physics
- Freie Universität Berlin
- 1495 Berlin
- Germany
| | - U.-P. Apfel
- Faculty of Chemistry and Biochemistry
- Ruhr-Universität Bochum
- 44801 Bochum
- Germany
- Fraunhofer UMSICHT
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36
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Lampret O, Adamska-Venkatesh A, Konegger H, Wittkamp F, Apfel UP, Reijerse EJ, Lubitz W, Rüdiger O, Happe T, Winkler M. Interplay between CN - Ligands and the Secondary Coordination Sphere of the H-Cluster in [FeFe]-Hydrogenases. J Am Chem Soc 2017; 139:18222-18230. [PMID: 29179539 DOI: 10.1021/jacs.7b08735] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The catalytic cofactor of [FeFe]-hydrogenses (H-cluster) is composed of a generic cubane [4Fe-4S]-cluster (4FeH) linked to a binuclear iron-sulfur cluster (2FeH) that has an open coordination site at which the reversible conversion of protons to molecular hydrogen occurs. The (2FeH) subsite features a diatomic coordination sphere composed of three CO and two CN- ligands affecting its redox properties and providing excellent probes for FTIR spectroscopy. The CO stretch vibrations are very sensitive to the redox changes within the H-cluster occurring during the catalytic cycle, whereas the CN- signals seem to be relatively inert to these effects. This could be due to the more structural role of the CN- ligands tightly anchoring the (2FeH) unit to the protein environment through hydrogen bonding. In this work we explore the effects of structural changes within the secondary ligand sphere affecting the CN- ligands on FTIR spectroscopy and catalysis. By comparing the FTIR spectra of wild-type enzyme and two mutagenesis variants, we are able to assign the IR signals of the individual CN- ligands of the (2FeH) site for different redox states of the H-cluster. Moreover, protein film electrochemistry reveals that targeted manipulation of the secondary coordination sphere of the proximal CN- ligand (i.e., closest to the (4FeH) site) can affect the catalytic bias. These findings highlight the importance of the protein environment for re-adjusting the catalytic features of the H-cluster in individual enzymes and provide valuable information for the design of artificial hydrogenase mimics.
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Affiliation(s)
- Oliver Lampret
- Fakultät für Biologie und Biotechnologie, Lehrstuhl für Biochemie der Pflanzen, AG Photobiotechnologie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Agnieszka Adamska-Venkatesh
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Hannes Konegger
- Fakultät für Biologie und Biotechnologie, Lehrstuhl für Biochemie der Pflanzen, AG Photobiotechnologie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Florian Wittkamp
- Fakultät für Chemie und Biochemie, Lehrstuhl für Anorganische Chemie I-Bioanorganische Chemie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Ulf-Peter Apfel
- Fakultät für Chemie und Biochemie, Lehrstuhl für Anorganische Chemie I-Bioanorganische Chemie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Edward J Reijerse
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Olaf Rüdiger
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Thomas Happe
- Fakultät für Biologie und Biotechnologie, Lehrstuhl für Biochemie der Pflanzen, AG Photobiotechnologie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Martin Winkler
- Fakultät für Biologie und Biotechnologie, Lehrstuhl für Biochemie der Pflanzen, AG Photobiotechnologie, Ruhr Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
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37
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Senger M, Laun K, Wittkamp F, Duan J, Haumann M, Happe T, Winkler M, Apfel UP, Stripp ST. Protonengekoppelte Reduktion des katalytischen [4Fe-4S]-Zentrums in [FeFe]-Hydrogenasen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709910] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Moritz Senger
- Fakultät für Physik; Freie Universität Berlin; Arnimallee 14 1495 Berlin Deutschland
| | - Konstantin Laun
- Fakultät für Physik; Freie Universität Berlin; Arnimallee 14 1495 Berlin Deutschland
| | - Florian Wittkamp
- Fakultät für Chemie und Biochemie; Ruhr-Universität Bochum; Universitätstraße 150 44801 Bochum Deutschland
| | - Jifu Duan
- Fakultät für Biologie und Biotechnologie; Ruhr-Universität Bochum; Universitätsstraße 150 44801 Bochum Deutschland
| | - Michael Haumann
- Fakultät für Physik; Freie Universität Berlin; Arnimallee 14 1495 Berlin Deutschland
| | - Thomas Happe
- Fakultät für Biologie und Biotechnologie; Ruhr-Universität Bochum; Universitätsstraße 150 44801 Bochum Deutschland
| | - Martin Winkler
- Fakultät für Biologie und Biotechnologie; Ruhr-Universität Bochum; Universitätsstraße 150 44801 Bochum Deutschland
| | - Ulf-Peter Apfel
- Fakultät für Chemie und Biochemie; Ruhr-Universität Bochum; Universitätstraße 150 44801 Bochum Deutschland
| | - Sven T. Stripp
- Fakultät für Physik; Freie Universität Berlin; Arnimallee 14 1495 Berlin Deutschland
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38
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Senger M, Laun K, Wittkamp F, Duan J, Haumann M, Happe T, Winkler M, Apfel UP, Stripp ST. Proton-Coupled Reduction of the Catalytic [4Fe-4S] Cluster in [FeFe]-Hydrogenases. Angew Chem Int Ed Engl 2017; 56:16503-16506. [PMID: 29072356 DOI: 10.1002/anie.201709910] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/23/2017] [Indexed: 12/25/2022]
Abstract
In nature, [FeFe]-hydrogenases catalyze the uptake and release of molecular hydrogen (H2 ) at a unique iron-sulfur cofactor. The absence of an electrochemical overpotential in the H2 release reaction makes [FeFe]-hydrogenases a prime example of efficient biocatalysis. However, the molecular details of hydrogen turnover are not yet fully understood. Herein, we characterize the initial one-electron reduction of [FeFe]-hydrogenases by infrared spectroscopy and electrochemistry and present evidence for proton-coupled electron transport during the formation of the reduced state Hred'. Charge compensation stabilizes the excess electron at the [4Fe-4S] cluster and maintains a conservative configuration of the diiron site. The role of Hred' in hydrogen turnover and possible implications on the catalytic mechanism are discussed. We propose that regulation of the electronic properties in the periphery of metal cofactors is key to orchestrating multielectron processes.
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Affiliation(s)
- Moritz Senger
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 1495, Berlin, Germany
| | - Konstantin Laun
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 1495, Berlin, Germany
| | - Florian Wittkamp
- Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätstrasse 150, 44801, Bochum, Germany
| | - Jifu Duan
- Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Michael Haumann
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 1495, Berlin, Germany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Martin Winkler
- Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Ulf-Peter Apfel
- Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätstrasse 150, 44801, Bochum, Germany
| | - Sven T Stripp
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 1495, Berlin, Germany
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39
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Sensi M, Baffert C, Fradale L, Gauquelin C, Soucaille P, Meynial-Salles I, Bottin H, de Gioia L, Bruschi M, Fourmond V, Léger C, Bertini L. Photoinhibition of FeFe Hydrogenase. ACS Catal 2017. [DOI: 10.1021/acscatal.7b02252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Matteo Sensi
- Aix Marseille University, CNRS, BIP UMR 7281, 13402 CEDEX 20 Marseille, France
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | - Carole Baffert
- Aix Marseille University, CNRS, BIP UMR 7281, 13402 CEDEX 20 Marseille, France
| | - Laura Fradale
- Aix Marseille University, CNRS, BIP UMR 7281, 13402 CEDEX 20 Marseille, France
| | - Charles Gauquelin
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135
CNRS:UMR 5504, Avenue
de Rangueil, 31077 Toulouse, France
| | - Philippe Soucaille
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135
CNRS:UMR 5504, Avenue
de Rangueil, 31077 Toulouse, France
| | - Isabelle Meynial-Salles
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135
CNRS:UMR 5504, Avenue
de Rangueil, 31077 Toulouse, France
| | - Hervé Bottin
- Institut
de Biologie Intégrative de la Cellule (I2BC), Institut Frédéric
Joliot, CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, F-91198 CEDEX Gif-Sur-Yvette, France
| | - Luca de Gioia
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | - Maurizio Bruschi
- Department
of Earth and Environmental Sciences, Milano-Bicocca University, Piazza della
Scienza 1, 20126 Milan, Italy
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | - Vincent Fourmond
- Aix Marseille University, CNRS, BIP UMR 7281, 13402 CEDEX 20 Marseille, France
| | - Christophe Léger
- Aix Marseille University, CNRS, BIP UMR 7281, 13402 CEDEX 20 Marseille, France
| | - Luca Bertini
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
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40
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Kositzki R, Mebs S, Schuth N, Leidel N, Schwartz L, Karnahl M, Wittkamp F, Daunke D, Grohmann A, Apfel UP, Gloaguen F, Ott S, Haumann M. Electronic and molecular structure relations in diiron compounds mimicking the [FeFe]-hydrogenase active site studied by X-ray spectroscopy and quantum chemistry. Dalton Trans 2017; 46:12544-12557. [PMID: 28905949 DOI: 10.1039/c7dt02720f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Synthetic diiron compounds of the general formula Fe2(μ-S2R)(CO)n(L)6-n (R = alkyl or aromatic groups; L = CN- or phosphines) are versatile models for the active-site cofactor of hydrogen turnover in [FeFe]-hydrogenases. A series of 18 diiron compounds, containing mostly a dithiolate bridge and terminal ligands of increasing complexity, was characterized by X-ray absorption and emission spectroscopy in combination with density functional theory. Fe K-edge absorption and Kβ main-line emission spectra revealed the varying geometry and the low-spin state of the Fe(i) centers. Good agreement between experimental and calculated core-to-valence-excitation absorption and radiative valence-to-core-decay emission spectra revealed correlations between spectroscopic and structural features and provided access to the electronic configuration. Four main effects on the diiron core were identified, which were preferentially related to variation either of the dithiolate or of the terminal ligands. Alteration of the dithiolate bridge affected mainly the Fe-Fe bond strength, while more potent donor substitution and ligand field asymmetrization changed the metal charge and valence level localization. In contrast, cyanide ligation altered all relevant properties and, in particular, the frontier molecular orbital energies of the diiron core. Mutual benchmarking of experimental and theoretical parameters provides guidelines to verify the electronic properties of related diiron compounds.
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Affiliation(s)
- Ramona Kositzki
- Freie Universität Berlin, Fachbereich Physik, 14195 Berlin, Germany.
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41
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Schilter D, Camara JM, Huynh MT, Hammes-Schiffer S, Rauchfuss TB. Hydrogenase Enzymes and Their Synthetic Models: The Role of Metal Hydrides. Chem Rev 2016; 116:8693-749. [PMID: 27353631 PMCID: PMC5026416 DOI: 10.1021/acs.chemrev.6b00180] [Citation(s) in RCA: 397] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogenase enzymes efficiently process H2 and protons at organometallic FeFe, NiFe, or Fe active sites. Synthetic modeling of the many H2ase states has provided insight into H2ase structure and mechanism, as well as afforded catalysts for the H2 energy vector. Particularly important are hydride-bearing states, with synthetic hydride analogues now known for each hydrogenase class. These hydrides are typically prepared by protonation of low-valent cores. Examples of FeFe and NiFe hydrides derived from H2 have also been prepared. Such chemistry is more developed than mimicry of the redox-inactive monoFe enzyme, although functional models of the latter are now emerging. Advances in physical and theoretical characterization of H2ase enzymes and synthetic models have proven key to the study of hydrides in particular, and will guide modeling efforts toward more robust and active species optimized for practical applications.
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Affiliation(s)
- David Schilter
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - James M. Camara
- Department of Chemistry, Yeshiva University, 500 West 185th Street, New York, New York 10033, United States
| | - Mioy T. Huynh
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Thomas B. Rauchfuss
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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42
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Birrell JA, Wrede K, Pawlak K, Rodriguez-Maciá P, Rüdiger O, Reijerse EJ, Lubitz W. Artificial Maturation of the Highly Active Heterodimeric [FeFe] Hydrogenase from Desulfovibrio desulfuricans
ATCC 7757. Isr J Chem 2016. [DOI: 10.1002/ijch.201600035] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- James A. Birrell
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Kathrin Wrede
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Krzysztof Pawlak
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Patricia Rodriguez-Maciá
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Olaf Rüdiger
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Edward J. Reijerse
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
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43
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Stepwise isotope editing of [FeFe]-hydrogenases exposes cofactor dynamics. Proc Natl Acad Sci U S A 2016; 113:8454-9. [PMID: 27432985 DOI: 10.1073/pnas.1606178113] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The six-iron cofactor of [FeFe]-hydrogenases (H-cluster) is the most efficient H2-forming catalyst in nature. It comprises a diiron active site with three carbon monoxide (CO) and two cyanide (CN(-)) ligands in the active oxidized state (Hox) and one additional CO ligand in the inhibited state (Hox-CO). The diatomic ligands are sensitive reporter groups for structural changes of the cofactor. Their vibrational dynamics were monitored by real-time attenuated total reflection Fourier-transform infrared spectroscopy. Combination of (13)CO gas exposure, blue or red light irradiation, and controlled hydration of three different [FeFe]-hydrogenase proteins produced 8 Hox and 16 Hox-CO species with all possible isotopic exchange patterns. Extensive density functional theory calculations revealed the vibrational mode couplings of the carbonyl ligands and uniquely assigned each infrared spectrum to a specific labeling pattern. For Hox-CO, agreement between experimental and calculated infrared frequencies improved by up to one order of magnitude for an apical CN(-) at the distal iron ion of the cofactor as opposed to an apical CO. For Hox, two equally probable isomers with partially rotated ligands were suggested. Interconversion between these structures implies dynamic ligand reorientation at the H-cluster. Our experimental protocol for site-selective (13)CO isotope editing combined with computational species assignment opens new perspectives for characterization of functional intermediates in the catalytic cycle.
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44
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Liu YC, Chu KT, Huang YL, Hsu CH, Lee GH, Tseng MC, Chiang MH. Protonation/Reduction of Carbonyl-Rich Diiron Complexes and the Direct Observation of Triprotonated Species: Insights into the Electrocatalytic Mechanism of Hydrogen Formation. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02646] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu-Chiao Liu
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Kai-Ti Chu
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
- Molecular
Science and Technology Program, TIGP, Institute of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
- Department
of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Yi-Lan Huang
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Cheng-Huey Hsu
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Gene-Hsiang Lee
- Instrumentation
Center, National Taiwan University, Taipei 106, Taiwan
| | - Mei-Chun Tseng
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Ming-Hsi Chiang
- Institute
of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
- Molecular
Science and Technology Program, TIGP, Institute of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
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45
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Zheng D, Wang M, Wang N, Cheng M, Sun L. Effect of Bridgehead Steric Bulk on the Intramolecular C-H Heterolysis of [FeFe]-Hydrogenase Active Site Models Containing a P2N2 Pendant Amine Ligand. Inorg Chem 2016; 55:411-8. [PMID: 26230977 DOI: 10.1021/acs.inorgchem.5b00923] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of pendant amine-containing [FeFe]-hydrogenase models, [X(CH2S-μ)2{Fe(CO)3}{Fe(CO)(P2(Ph)N2(Bn))}] (1H, X = CH2; 2Me, C(CH3)2; 3Et, C(CH2CH3)2; and P2(Ph)N2(Bn) = 1,5-dibenzyl-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane) with different groups at the bridgehead carbon of the S-to-S linker were synthesized. The oxidations of these complexes as well as the reverse reduction reaction were studied by cyclic voltammetry and in situ IR spectroscopy. Regardless of the bridgehead steric bulk, all three complexes demonstrate intramolecular iron-mediated C(sp(3))-H bond heterolytic cleavage with the assistance of the pendant amine base within the chelating diphosphine ligand in the two-electron oxidation process. X-ray crystallographic analysis shows that the doubly oxidized products, [1'H](+), [2'Me](+), and [3'Et](+), all have a rigid FeSC three-membered ring at the open apical site of the rotated iron center. The most noticeable difference in structures of the oxidized complexes is that the single CO ligand of the rotated Fe(P2(Ph)N2(Bn))(CO) unit in [1'H](+) and [2'Me](+) is found below the Fe···Fe vector, while in [3'Et](+) an unusually rotated Fe(P2(Ph)N2(Bn))(CO) moiety positions one of the P donors within the bidentate ligand under the Fe···Fe vector. The starting Fe(I)Fe(I) complexes can be recovered from their corresponding doubly oxidized complexes by reduction in the presence of Brönsted acid.
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Affiliation(s)
- Dehua Zheng
- State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT) , Dalian 116024, China
| | - Mei Wang
- State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT) , Dalian 116024, China
| | - Ning Wang
- School of Chemistry and Chemical Engineering, Henan University of Technology , Zhengzhou 450001, China
| | - Minglun Cheng
- State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT) , Dalian 116024, China
| | - Licheng Sun
- State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT) , Dalian 116024, China.,Department of Chemistry, KTH Royal Institute of Technology , Stockholm 10044, Sweden
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46
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Chang CH, Kim K. Density Functional Theory Calculation of Bonding and Charge Parameters for Molecular Dynamics Studies on [FeFe] Hydrogenases. J Chem Theory Comput 2015; 5:1137-45. [PMID: 26609623 DOI: 10.1021/ct800342w] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We have developed and tested molecular mechanics parameters for [FeS] clusters found in known [FeFe] hydrogenases. Bond stretching, angle bending, dihedral and improper torsion parameters for models of the oxidized and reduced catalytic H-cluster, [4Fe4S](+,2+)Cys4, [4Fe4S](+,2+)Cys3His, and [2Fe2S](+,2+)Cys4, were calculated solely from Kohn-Sham density functional theory and Natural Population Analysis. Circumsphere analysis of the cubane clusters in the energy-minimized structure of the full Clostridium pasteurianum hydrogenase I showed the resulting metallocluster structures to be similar to known cubane structures. All clusters were additionally stable in molecular dynamics simulations over the course of 1.0 ns in the fully oxidized and fully reduced enzyme models. Normal modes calculated by quasiharmonic analysis from the dynamics data show unexpected couplings among internal coordinate motions, which may reflect the effects of the protein structure on metallocluster dynamics.
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Affiliation(s)
- Christopher H Chang
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - Kwiseon Kim
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
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47
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Morra S, Maurelli S, Chiesa M, Mulder DW, Ratzloff MW, Giamello E, King PW, Gilardi G, Valetti F. The effect of a C298D mutation in CaHydA [FeFe]-hydrogenase: Insights into the protein-metal cluster interaction by EPR and FTIR spectroscopic investigation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:98-106. [PMID: 26482707 DOI: 10.1016/j.bbabio.2015.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 10/01/2015] [Accepted: 10/15/2015] [Indexed: 01/17/2023]
Abstract
A conserved cysteine located in the signature motif of the catalytic center (H-cluster) of [FeFe]-hydrogenases functions in proton transfer. This residue corresponds to C298 in Clostridium acetobutylicum CaHydA. Despite the chemical and structural difference, the mutant C298D retains fast catalytic activity, while replacement with any other amino acid causes significant activity loss. Given the proximity of C298 to the H-cluster, the effect of the C298D mutation on the catalytic center was studied by continuous wave (CW) and pulse electron paramagnetic resonance (EPR) and by Fourier transform infrared (FTIR) spectroscopies. Comparison of the C298D mutant with the wild type CaHydA by CW and pulse EPR showed that the electronic structure of the center is not altered. FTIR spectroscopy confirmed that absorption peak values observed in the mutant are virtually identical to those observed in the wild type, indicating that the H-cluster is not generally affected by the mutation. Significant differences were observed only in the inhibited state Hox-CO: the vibrational modes assigned to the COexo and Fed-CO in this state are shifted to lower values in C298D, suggesting different interaction of these ligands with the protein moiety when C298 is changed to D298. More relevant to the catalytic cycle, the redox equilibrium between the Hox and Hred states is modified by the mutation, causing a prevalence of the oxidized state. This work highlights how the interactions between the protein environment and the H-cluster, a dynamic closely interconnected system, can be engineered and studied in the perspective of designing bio-inspired catalysts and mimics.
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Affiliation(s)
- Simone Morra
- Department of Life Sciences and Systems Biology, University of Torino, Torino 10133, Italy
| | - Sara Maurelli
- Department of Chemistry, University of Torino, Torino 10133, Italy
| | - Mario Chiesa
- Department of Chemistry, University of Torino, Torino 10133, Italy
| | - David W Mulder
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Michael W Ratzloff
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Elio Giamello
- Department of Chemistry, University of Torino, Torino 10133, Italy
| | - Paul W King
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Gianfranco Gilardi
- Department of Life Sciences and Systems Biology, University of Torino, Torino 10133, Italy
| | - Francesca Valetti
- Department of Life Sciences and Systems Biology, University of Torino, Torino 10133, Italy.
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48
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Adamska-Venkatesh A, Roy S, Siebel JF, Simmons TR, Fontecave M, Artero V, Reijerse E, Lubitz W. Spectroscopic Characterization of the Bridging Amine in the Active Site of [FeFe] Hydrogenase Using Isotopologues of the H-Cluster. J Am Chem Soc 2015; 137:12744-7. [PMID: 26393426 DOI: 10.1021/jacs.5b06240] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The active site of [FeFe] hydrogenase contains a catalytic binuclear iron subsite coordinated by CN(-) and CO ligands as well as a unique azadithiolate (adt(2-)) bridging ligand. It has been established that this binuclear cofactor is synthesized and assembled by three maturation proteins HydE, -F, and -G. By means of in vitro maturation in the presence of (15)N- and (13)C-labeled tyrosine it has been shown that the CN(-) and CO ligands originate from tyrosine. The source of the bridging adt(2-) ligand, however, remains unknown. In order to identify the nitrogen of the bridging amine using HYSCORE spectroscopy and distinguish its spectroscopic signature from that of the CN(-) nitrogens, we studied three isotope-labeled variants of the H-cluster ((15)N-adt(2-)/C(14)N(-), (15)N-adt(2-)/C(15)N(-), and (14)N-adt(2-)/C(15)N(-)) and extracted accurate values of the hyperfine and quadrupole couplings of both CN(-) and adt(2-) nitrogens. This will allow an evaluation of isotopologues of the H-cluster generated by in vitro bioassembly in the presence of various (15)N-labeled potential precursors as possible sources of the bridging ligand.
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Affiliation(s)
- Agnieszka Adamska-Venkatesh
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Souvik Roy
- Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CEA, CNRS , 17 rue des martyrs, 38000 Grenoble, France
| | - Judith F Siebel
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Trevor R Simmons
- Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CEA, CNRS , 17 rue des martyrs, 38000 Grenoble, France
| | - Marc Fontecave
- Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CEA, CNRS , 17 rue des martyrs, 38000 Grenoble, France.,Laboratoire de Chimie des Processus Biologiques, Collège de France, Université Pierre et Marie Curie, CNRS UMR 8229 , 11 place Marcelin Berthelot, 75005 Paris, France
| | - Vincent Artero
- Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CEA, CNRS , 17 rue des martyrs, 38000 Grenoble, France
| | - Edward Reijerse
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
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49
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Adamska-Venkatesh A, Simmons TR, Siebel JF, Artero V, Fontecave M, Reijerse E, Lubitz W. Artificially maturated [FeFe] hydrogenase from Chlamydomonas reinhardtii: a HYSCORE and ENDOR study of a non-natural H-cluster. Phys Chem Chem Phys 2015; 17:5421-30. [PMID: 25613229 DOI: 10.1039/c4cp05426a] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogenases are enzymes that catalyze the oxidation of H2 as well as the reduction of protons to form H2. The active site of [FeFe] hydrogenase is referred to as the "H-cluster" and consists of a "classical" [4Fe-4S] cluster connected via a bridging cysteine thiol group to a unique [2Fe]H sub-cluster, containing CN(-) and CO ligands as well as a bidentate azadithiolate ligand. It has been recently shown that the biomimetic [Fe2(adt)(CO)4(CN)2](2-) (adt(2-) = azadithiolate) complex resembling the diiron sub-cluster can be inserted in vitro into the apo-protein of [FeFe] hydrogenase, which contains only the [4Fe-4S] part of the H-cluster, resulting in a fully active enzyme. This synthetic tool allows convenient incorporation of a variety of diiron mimics, thus generating hydrogenases with artificial active sites. [FeFe] hydrogenase from Chlamydomonas reinhardtii maturated with the biomimetic complex [Fe2(pdt)(CO)4(CN)2](2-) (pdt(2-) = propanedithiolate), in which the bridging adt(2-) ligand is replaced by pdt(2-), can be stabilized in a state strongly resembling the active oxidized (Hox) state of the native protein. This state is EPR active and the signal originates from the mixed valence Fe(I)Fe(II) state of the diiron sub-cluster. Taking advantage of the variant with (15)N and (13)C isotope labeled CN(-) ligands we performed HYSCORE and ENDOR studies on this hybrid protein. The (13)C hyperfine couplings originating from both CN(-) ligands were determined and assigned. Only the (15)N coupling from the CN(-) ligand bound to the terminal iron was observed. Detailed orientation selective ENDOR and HYSCORE experiments at multiple field positions enabled the extraction of accurate data for the relative orientations of the nitrogen and carbon hyperfine tensors. These data are consistent with the crystal structure assuming a g-tensor orientation following the local symmetry of the binuclear sub-cluster.
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Affiliation(s)
- Agnieszka Adamska-Venkatesh
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany.
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50
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Abstract
Proton reduction and H2 oxidation are key elementary reactions for solar fuel production. Hydrogenases interconvert H+ and H2 with remarkable efficiency and have therefore received much attention in this context. For [FeFe]-hydrogenases, catalysis occurs at a unique cofactor called the H-cluster. In this article, we discuss ways in which EPR spectroscopy has elucidated aspects of the bioassembly of the H-cluster, with a focus on four case studies: EPR spectroscopic identification of a radical en route to the CO and CN- ligands of the H-cluster, tracing 57Fe from the maturase HydG into the H-cluster, characterization of the auxiliary Fe-S cluster in HydG, and isotopic labeling of the CN- ligands of HydA for electronic structure studies of its Hox state. Advances in cell-free maturation protocols have enabled several of these mechanistic studies, and understanding H-cluster maturation may in turn provide insights leading to improvements in hydrogenase production for biotechnological applications.
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Affiliation(s)
- Daniel L. M. Suess
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - R. David Britt
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA
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