1
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Brocks C, Das CK, Duan J, Yadav S, Apfel UP, Ghosh S, Hofmann E, Winkler M, Engelbrecht V, Schäfer LV, Happe T. A Dynamic Water Channel Affects O 2 Stability in [FeFe]-Hydrogenases. CHEMSUSCHEM 2024; 17:e202301365. [PMID: 37830175 DOI: 10.1002/cssc.202301365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023]
Abstract
[FeFe]-hydrogenases are capable of reducing protons at a high rate. However, molecular oxygen (O2 ) induces the degradation of their catalytic cofactor, the H-cluster, which consists of a cubane [4Fe4S] subcluster (4FeH ) and a unique diiron moiety (2FeH ). Previous attempts to prevent O2 -induced damage have focused on enhancing the protein's sieving effect for O2 by blocking the hydrophobic gas channels that connect the protein surface and the 2FeH . In this study, we aimed to block an O2 diffusion pathway and shield 4FeH instead. Molecular dynamics (MD) simulations identified a novel water channel (WH ) surrounding the H-cluster. As this hydrophilic path may be accessible for O2 molecules we applied site-directed mutagenesis targeting amino acids along WH in proximity to 4FeH to block O2 diffusion. Protein film electrochemistry experiments demonstrate increased O2 stabilities for variants G302S and S357T, and MD simulations based on high-resolution crystal structures confirmed an enhanced local sieving effect for O2 in the environment of the 4FeH in both cases. The results strongly suggest that, in wild type proteins, O2 diffuses from the 4FeH to the 2FeH . These results reveal new strategies for improving the O2 stability of [FeFe]-hydrogenases by focusing on the O2 diffusion network near the active site.
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Affiliation(s)
- Claudia Brocks
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Chandan K Das
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Jifu Duan
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Shanika Yadav
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Ulf-Peter Apfel
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Subhasri Ghosh
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Eckhard Hofmann
- Faculty of Biology and Biotechnology, X-ray structure analysis of proteins, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Martin Winkler
- Electrobiotechnology, TUM Campus Straubing, Schulgasse 22, Straubing, 94315, Germany
| | - Vera Engelbrecht
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Lars V Schäfer
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
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2
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Kim SM, Kang SH, Jeon BW, Kim YH. Tunnel engineering of gas-converting enzymes for inhibitor retardation and substrate acceleration. BIORESOURCE TECHNOLOGY 2024; 394:130248. [PMID: 38158090 DOI: 10.1016/j.biortech.2023.130248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Carbon monoxide dehydrogenase (CODH), formate dehydrogenase (FDH), hydrogenase (H2ase), and nitrogenase (N2ase) are crucial enzymatic catalysts that facilitate the conversion of industrially significant gases such as CO, CO2, H2, and N2. The tunnels in the gas-converting enzymes serve as conduits for these low molecular weight gases to access deeply buried catalytic sites. The identification of the substrate tunnels is imperative for comprehending the substrate selectivity mechanism underlying these gas-converting enzymes. This knowledge also holds substantial value for industrial applications, particularly in addressing the challenges associated with separation and utilization of byproduct gases. In this comprehensive review, we delve into the emerging field of tunnel engineering, presenting a range of approaches and analyses. Additionally, we propose methodologies for the systematic design of enzymes, with the ultimate goal of advancing protein engineering strategies.
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Affiliation(s)
- Suk Min Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
| | - Sung Heuck Kang
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Byoung Wook Jeon
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Yong Hwan Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea; Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
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3
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Evans RM, Beaton SE, Rodriguez Macia P, Pang Y, Wong KL, Kertess L, Myers WK, Bjornsson R, Ash PA, Vincent KA, Carr SB, Armstrong FA. Comprehensive structural, infrared spectroscopic and kinetic investigations of the roles of the active-site arginine in bidirectional hydrogen activation by the [NiFe]-hydrogenase 'Hyd-2' from Escherichia coli. Chem Sci 2023; 14:8531-8551. [PMID: 37592998 PMCID: PMC10430524 DOI: 10.1039/d2sc05641k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 07/01/2023] [Indexed: 08/19/2023] Open
Abstract
The active site of [NiFe]-hydrogenases contains a strictly-conserved pendant arginine, the guanidine head group of which is suspended immediately above the Ni and Fe atoms. Replacement of this arginine (R479) in hydrogenase-2 from E. coli results in an enzyme that is isolated with a very tightly-bound diatomic ligand attached end-on to the Ni and stabilised by hydrogen bonding to the Nζ atom of the pendant lysine and one of the three additional water molecules located in the active site of the variant. The diatomic ligand is bound under oxidising conditions and is removed only after a prolonged period of reduction with H2 and reduced methyl viologen. Once freed of the diatomic ligand, the R479K variant catalyses both H2 oxidation and evolution but with greatly decreased rates compared to the native enzyme. Key kinetic characteristics are revealed by protein film electrochemistry: most importantly, a very low activation energy for H2 oxidation that is not linked to an increased H/D isotope effect. Native electrocatalytic reversibility is retained. The results show that the sluggish kinetics observed for the lysine variant arise most obviously because the advantage of a more favourable low-energy pathway is massively offset by an extremely unfavourable activation entropy. Extensive efforts to establish the identity of the diatomic ligand, the tight binding of which is an unexpected further consequence of replacing the pendant arginine, prove inconclusive.
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Affiliation(s)
- Rhiannon M Evans
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Stephen E Beaton
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | | | - Yunjie Pang
- College of Chemistry, Beijing Normal University 100875 Beijing China
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
| | - Kin Long Wong
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus Didcot UK
| | - Leonie Kertess
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - William K Myers
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Ragnar Bjornsson
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
- Univ Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire Chimie et Biologie des Métaux 17 Rue Des Martyrs F-38054 Grenoble Cedex France
| | - Philip A Ash
- School of Chemistry, The University of Leicester University Road Leicester LE1 7RH UK
| | - Kylie A Vincent
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Stephen B Carr
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus Didcot UK
| | - Fraser A Armstrong
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
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4
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Jiang Q, Li T, Yang J, Aitchison CM, Huang J, Chen Y, Huang F, Wang Q, Cooper AI, Liu LN. Synthetic engineering of a new biocatalyst encapsulating [NiFe]-hydrogenases for enhanced hydrogen production. J Mater Chem B 2023; 11:2684-2692. [PMID: 36883480 PMCID: PMC10032307 DOI: 10.1039/d2tb02781j] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Hydrogenases are microbial metalloenzymes capable of catalyzing the reversible interconversion between molecular hydrogen and protons with high efficiency, and have great potential in the development of new electrocatalysts for renewable fuel production. Here, we engineered the intact proteinaceous shell of the carboxysome, a self-assembling protein organelle for CO2 fixation in cyanobacteria and proteobacteria, and sequestered heterologously produced [NiFe]-hydrogenases into the carboxysome shell. The protein-based hybrid catalyst produced in E. coli shows substantially improved hydrogen production under both aerobic and anaerobic conditions and enhanced material and functional robustness, compared to unencapsulated [NiFe]-hydrogenases. The catalytically functional nanoreactor as well as the self-assembling and encapsulation strategies provide a framework for engineering new bioinspired electrocatalysts to improve the sustainable production of fuels and chemicals in biotechnological and chemical applications.
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Affiliation(s)
- Qiuyao Jiang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Tianpei Li
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Jing Yang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
- Materials Innovation Factory and Department of Chemistry, University of Liverpool, Liverpool L7 3NY, UK
| | - Catherine M Aitchison
- Materials Innovation Factory and Department of Chemistry, University of Liverpool, Liverpool L7 3NY, UK
| | - Jiafeng Huang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Yu Chen
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Fang Huang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Andrew I Cooper
- Materials Innovation Factory and Department of Chemistry, University of Liverpool, Liverpool L7 3NY, UK
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
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5
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Steinhilper R, Höff G, Heider J, Murphy BJ. Structure of the membrane-bound formate hydrogenlyase complex from Escherichia coli. Nat Commun 2022; 13:5395. [PMID: 36104349 PMCID: PMC9474812 DOI: 10.1038/s41467-022-32831-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 08/08/2022] [Indexed: 01/30/2023] Open
Abstract
The prototypical hydrogen-producing enzyme, the membrane-bound formate hydrogenlyase (FHL) complex from Escherichia coli, links formate oxidation at a molybdopterin-containing formate dehydrogenase to proton reduction at a [NiFe] hydrogenase. It is of intense interest due to its ability to efficiently produce H2 during fermentation, its reversibility, allowing H2-dependent CO2 reduction, and its evolutionary link to respiratory complex I. FHL has been studied for over a century, but its atomic structure remains unknown. Here we report cryo-EM structures of FHL in its aerobically and anaerobically isolated forms at resolutions reaching 2.6 Å. This includes well-resolved density for conserved loops linking the soluble and membrane arms believed to be essential in coupling enzymatic turnover to ion translocation across the membrane in the complex I superfamily. We evaluate possible structural determinants of the bias toward hydrogen production over its oxidation and describe an unpredicted metal-binding site near the interface of FdhF and HycF subunits that may play a role in redox-dependent regulation of FdhF interaction with the complex. New cryo-EM structures of the formate hydrogenlyase complex from the model bacterium E. coli clarify how electrons and protons move through the complex and are combined to make H2 gas. The complex shows important similarities and differences to related bioenergetic complexes across the tree of life.
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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: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gases like H2, N2, CO2, and CO are increasingly recognized as critical feedstock in "green" energy conversion and as sources of nitrogen and carbon for the agricultural and chemical sectors. However, the industrial transformation of N2, CO2, and CO and the production of H2 require significant energy input, which renders processes like steam reforming and the Haber-Bosch reaction economically and environmentally unviable. Nature, on the other hand, performs similar tasks efficiently at ambient temperature and pressure, exploiting gas-processing metalloenzymes (GPMs) that bind low-valent metal cofactors based on iron, nickel, molybdenum, tungsten, and sulfur. Such systems are studied to understand the biocatalytic principles of gas conversion including N2 fixation by nitrogenase and H2 production by hydrogenase as well as CO2 and CO conversion by formate dehydrogenase, carbon monoxide dehydrogenase, and nitrogenase. In this review, we emphasize the importance of the cofactor/protein interface, discussing how second and outer coordination sphere effects determine, modulate, and optimize the catalytic activity of GPMs. These may comprise ionic interactions in the second coordination sphere that shape the electron density distribution across the cofactor, hydrogen bonding changes, and allosteric effects. In the outer coordination sphere, proton transfer and electron transfer are discussed, alongside the role of hydrophobic substrate channels and protein structural changes. Combining the information gained from structural biology, enzyme kinetics, and various spectroscopic techniques, we aim toward a comprehensive understanding of catalysis beyond the first coordination sphere.
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Affiliation(s)
- Sven T Stripp
- Freie Universität Berlin, Experimental Molecular Biophysics, Berlin 14195, Germany
| | | | - Vincent Fourmond
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, Institut Microbiologie, Bioénergies et Biotechnologie, CNRS, Aix Marseille Université, Marseille 13402, France
| | - Christophe Léger
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, Institut Microbiologie, Bioénergies et Biotechnologie, CNRS, Aix Marseille Université, Marseille 13402, France
| | - Silke Leimkühler
- University of Potsdam, Molecular Enzymology, Potsdam 14476, Germany
| | - Shun Hirota
- Nara Institute of Science and Technology, Division of Materials Science, Graduate School of Science and Technology, Nara 630-0192, Japan
| | - Yilin Hu
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States
| | - Andrew Jasniewski
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States
| | - Hideaki Ogata
- Nara Institute of Science and Technology, Division of Materials Science, Graduate School of Science and Technology, Nara 630-0192, Japan.,Hokkaido University, Institute of Low Temperature Science, Sapporo 060-0819, Japan.,Graduate School of Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Markus W Ribbe
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697-3900, United States.,Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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7
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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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8
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Evans RM, Krahn N, Murphy BJ, Lee H, Armstrong FA, Söll D. Selective cysteine-to-selenocysteine changes in a [NiFe]-hydrogenase confirm a special position for catalysis and oxygen tolerance. Proc Natl Acad Sci U S A 2021; 118:e2100921118. [PMID: 33753519 PMCID: PMC8020662 DOI: 10.1073/pnas.2100921118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In [NiFe]-hydrogenases, the active-site Ni is coordinated by four cysteine-S ligands (Cys; C), two of which are bridging to the Fe(CO)(CN)2 fragment. Substitution of a single Cys residue by selenocysteine (Sec; U) occurs occasionally in nature. Using a recent method for site-specific Sec incorporation into proteins, each of the four Ni-coordinating cysteine residues in the oxygen-tolerant Escherichia coli [NiFe]-hydrogenase-1 (Hyd-1) has been replaced by U to identify its importance for enzyme function. Steady-state solution activity of each Sec-substituted enzyme (on a per-milligram basis) is lowered, although this may reflect the unquantified presence of recalcitrant inactive/immature/misfolded forms. Protein film electrochemistry, however, reveals detailed kinetic data that are independent of absolute activities. Like native Hyd-1, the variants have low apparent KMH2 values, do not produce H2 at pH 6, and display the same onset overpotential for H2 oxidation. Mechanistically important differences were identified for the C576U variant bearing the equivalent replacement found in native [NiFeSe]-hydrogenases, its extreme O2 tolerance (apparent KMH2 and Vmax [solution] values relative to native Hyd-1 of 0.13 and 0.04, respectively) implying the importance of a selenium atom in the position cis to the site where exogenous ligands (H-, H2, O2) bind. Observation of the same unusual electrocatalytic signature seen earlier for the proton transfer-defective E28Q variant highlights the direct role of the chalcogen atom (S/Se) at position 576 close to E28, with the caveat that Se is less effective than S in facilitating proton transfer away from the Ni during H2 oxidation by this enzyme.
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Affiliation(s)
- Rhiannon M Evans
- Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511
| | - Bonnie J Murphy
- Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Harrison Lee
- Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Fraser A Armstrong
- Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, United Kingdom;
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511;
- Department of Chemistry, Yale University, New Haven, CT 06520
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9
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Vansuch GE, Wu CH, Haja DK, Blair SA, Chica B, Johnson MK, Adams MWW, Dyer RB. Metal-ligand cooperativity in the soluble hydrogenase-1 from Pyrococcus furiosus. Chem Sci 2020; 11:8572-8581. [PMID: 34123117 PMCID: PMC8163435 DOI: 10.1039/d0sc00628a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Metal–ligand cooperativity is an essential feature of bioinorganic catalysis. The design principles of such cooperativity in metalloenzymes are underexplored, but are critical to understand for developing efficient catalysts designed with earth abundant metals for small molecule activation. The simple substrate requirements of reversible proton reduction by the [NiFe]-hydrogenases make them a model bioinorganic system. A highly conserved arginine residue (R355) directly above the exogenous ligand binding position of the [NiFe]-catalytic core is known to be essential for optimal function because mutation to a lysine results in lower catalytic rates. To expand on our studies of soluble hydrogenase-1 from Pyrococcus furiosus (Pf SH1), we investigated the role of R355 by site-directed-mutagenesis to a lysine (R355K) using infrared and electron paramagnetic resonance spectroscopic probes sensitive to active site redox and protonation events. It was found the mutation resulted in an altered ligand binding environment at the [NiFe] centre. A key observation was destabilization of the Nia3+–C state, which contains a bridging hydride. Instead, the tautomeric Nia+–L states were observed. Overall, the results provided insight into complex metal–ligand cooperativity between the active site and protein scaffold that modulates the bridging hydride stability and the proton inventory, which should prove valuable to design principles for efficient bioinspired catalysts. Metal–ligand cooperativity is an essential feature of bioinorganic catalysis.![]()
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Affiliation(s)
| | - Chang-Hao Wu
- Department of Biochemistry & Molecular Biology, University of Georgia Athens Georgia 30602 USA.,AskGene Pharma Inc. Camarillo CA 93012 USA
| | - Dominik K Haja
- Department of Biochemistry & Molecular Biology, University of Georgia Athens Georgia 30602 USA
| | - Soshawn A Blair
- Department of Chemistry, University of Georgia Athens Georgia 30602 USA
| | - Bryant Chica
- Department of Chemistry, Emory University Atlanta Georgia 30222 USA .,Biosciences Center, National Renewable Energy Laboratory Golden Colorado 80401 USA
| | - Michael K Johnson
- Department of Chemistry, University of Georgia Athens Georgia 30602 USA
| | - Michael W W Adams
- Department of Biochemistry & Molecular Biology, University of Georgia Athens Georgia 30602 USA.,Department of Chemistry, University of Georgia Athens Georgia 30602 USA
| | - R Brian Dyer
- Department of Chemistry, Emory University Atlanta Georgia 30222 USA
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10
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Nishikawa K, Ogata H, Higuchi Y. Structural Basis of the Function of [NiFe]-hydrogenases. CHEM LETT 2020. [DOI: 10.1246/cl.190814] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Koji Nishikawa
- Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Hideaki Ogata
- Institute of Low Temperature Science, Hokkaido University, Kita19Nishi8, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Yoshiki Higuchi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
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11
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Ash PA, Kendall-Price SET, Vincent KA. Unifying Activity, Structure, and Spectroscopy of [NiFe] Hydrogenases: Combining Techniques To Clarify Mechanistic Understanding. Acc Chem Res 2019; 52:3120-3131. [PMID: 31675209 DOI: 10.1021/acs.accounts.9b00293] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Achieving a unified understanding of the mechanism of a multicenter redox enzyme such as [NiFe] hydrogenase is complicated by difficulties in reconciling information obtained by using different techniques and on samples in different physical forms. Measurements of the activity of the enzyme, and of factors which perturb activity, are generally carried out using biochemical assays in solution or with electrode-immobilized enzymes using protein film electrochemistry (PFE). Conversely, spectroscopy aimed at reporting on features of the metalloclusters in the enzyme, such as electron paramagnetic resonance (EPR) or X-ray absorption spectroscopy (XAS), is often conducted on frozen samples and is thus difficult to relate to catalytically relevant states as information about turnover and activity has been lost. To complicate matters further, most of our knowledge of the atomic-level structure of metalloenzymes comes from X-ray diffraction studies in the solid, crystalline state, which are again difficult to link to turnover conditions. Taking [NiFe] hydrogenases as our case study, we show here how it is possible to apply infrared (IR) spectroscopic sampling approaches to unite direct spectroscopic study with catalytic turnover. Using a method we have named protein film IR electrochemistry (PFIRE), we reveal the steady-state distribution of intermediates during catalysis and identify catalytic "bottlenecks" introduced by site-directed mutagenesis. We also show that it is possible to study dynamic transitions between active site states of enzymes in single crystals, uniting solid state and solution spectroscopic information. In all of these cases, the spectroscopic data complement and enhance interpretation of purely activity-based measurements by providing direct chemical insight that is otherwise hidden. The [NiFe] hydrogenases possess a bimetallic [NiFe] active site, coordinated by CO and CN- ligands, linked to the protein via bridging and terminal cysteine sulfur ligands, as well as an electron relay chain of iron sulfur clusters. Infrared spectroscopy is ideal for probing hydrogenases because the CO and CN- ligands are strong IR absorbers, but the suite of IR-based approaches we describe here will be equally valuable in studying substrate- or intermediate-bound states of other metalloenzymes where key mechanistic questions remain open, such as nitrogenase, formate dehydrogenase, or carbon monoxide dehydrogenase. We therefore hope that this Account will encourage future studies which unify information from different techniques across bioinorganic chemistry.
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Affiliation(s)
- Philip A. Ash
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
- School of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | | | - Kylie A. Vincent
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
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12
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Lu Y, Koo J. O 2 sensitivity and H 2 production activity of hydrogenases-A review. Biotechnol Bioeng 2019; 116:3124-3135. [PMID: 31403182 DOI: 10.1002/bit.27136] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 07/23/2019] [Accepted: 08/05/2019] [Indexed: 01/24/2023]
Abstract
Hydrogenases are metalloproteins capable of catalyzing the interconversion between molecular hydrogen and protons and electrons. The iron-sulfur clusters within the enzyme enable rapid relay of electrons which are either consumed or generated at the active site. Their unparalleled catalytic efficiency has attracted attention, especially for potential use in H2 production and/or fuel cell technologies. However, there are limitations to using hydrogenases, especially due to their high O2 sensitivity. The subclass, called [FeFe] hydrogenases, are particularly more vulnerable to O2 but proficient in H2 production. In this review, we provide an overview of mechanistic and protein engineering studies focused on understanding and enhancing O2 tolerance of the enzyme. The emphasis is on ongoing studies that attempt to overcome O2 sensitivity of the enzyme while it catalyzes H2 production in an aerobic environment. We also discuss pioneering attempts to utilize the enzyme in biological H2 production and other industrial processes, as well as our own perspective on future applications.
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Affiliation(s)
- Yuan Lu
- Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Jamin Koo
- Department of Chemical Engineering, Hongik University, Seoul, Republic of Korea
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13
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Slater JW, Marguet SC, Gray ME, Monaco HA, Sotomayor M, Shafaat HS. Power of the Secondary Sphere: Modulating Hydrogenase Activity in Nickel-Substituted Rubredoxin. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01720] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeffrey W. Slater
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Sean C. Marguet
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Michelle E. Gray
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Haleigh A. Monaco
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Marcos Sotomayor
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Hannah S. Shafaat
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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14
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Zanello P. Structure and electrochemistry of proteins harboring iron-sulfur clusters of different nuclearities. Part IV. Canonical, non-canonical and hybrid iron-sulfur proteins. J Struct Biol 2019; 205:103-120. [PMID: 30677521 DOI: 10.1016/j.jsb.2019.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/11/2019] [Accepted: 01/11/2019] [Indexed: 12/26/2022]
Abstract
A plethora of proteins are able to express iron-sulfur clusters, but have a clear picture of the different types of proteins and the different iron-sulfur clusters they harbor it is not easy. In the last five years we have reviewed structure/electrochemistry of metalloproteins expressing: (i) single types of iron-sulfur clusters (namely: {Fe(Cys)4}, {[Fe2S2](Cys)4}, {[Fe2S2](Cys)3(X)} (X = Asp, Arg, His), {[Fe2S2](Cys)2(His)2}, {[Fe3S4](Cys)3}, {[Fe4S4](Cys)4} and {[Fe4S4](Cys)3(nonthiolate ligand)} cores); (ii) metalloproteins harboring iron-sulfur centres of different nuclearities (namely: [4Fe-4S] and [2Fe-2S], [4Fe-4S] and [3Fe-4S], and [4Fe-4S], [3Fe-4S] and [2Fe-2S] clusters. Our target is now to review structure and electrochemistry of proteins harboring canonical, non-canonical and hybrid iron-sulfur proteins.
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Affiliation(s)
- Piero Zanello
- Dipartimento di Biotecnologie, Chimica e Farmacia dell'Università di Siena, Via A. De Gasperi 2, 53100 Siena, Italy
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15
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Thammavongsy Z, Mercer IP, Yang JY. Promoting proton coupled electron transfer in redox catalysts through molecular design. Chem Commun (Camb) 2019; 55:10342-10358. [DOI: 10.1039/c9cc05139b] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mini-review on using the secondary coordination sphere to facilitate multi-electron, multi-proton catalysis.
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Affiliation(s)
| | - Ian P. Mercer
- Department of Chemistry
- University of California
- Irvine
- USA
| | - Jenny Y. Yang
- Department of Chemistry
- University of California
- Irvine
- USA
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16
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Evans RM, Siritanaratkul B, Megarity CF, Pandey K, Esterle TF, Badiani S, Armstrong FA. The value of enzymes in solar fuels research – efficient electrocatalysts through evolution. Chem Soc Rev 2019; 48:2039-2052. [DOI: 10.1039/c8cs00546j] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes which evolved more than 2 billion years ago set exceptional standards for electrocatalysts being sought today.
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Affiliation(s)
- Rhiannon M. Evans
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | | | - Clare F. Megarity
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Kavita Pandey
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Thomas F. Esterle
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Selina Badiani
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Fraser A. Armstrong
- Department of Chemistry
- Inorganic Chemistry Laboratory
- University of Oxford
- Oxford
- UK
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17
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Evans RM, Ash PA, Beaton SE, Brooke EJ, Vincent KA, Carr SB, Armstrong FA. Mechanistic Exploitation of a Self-Repairing, Blocked Proton Transfer Pathway in an O2-Tolerant [NiFe]-Hydrogenase. J Am Chem Soc 2018; 140:10208-10220. [DOI: 10.1021/jacs.8b04798] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Rhiannon M. Evans
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Philip A. Ash
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Stephen E. Beaton
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Emily J. Brooke
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Kylie A. Vincent
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Stephen B. Carr
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Fraser A. Armstrong
- Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
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18
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Slater JW, Marguet SC, Monaco HA, Shafaat HS. Going beyond Structure: Nickel-Substituted Rubredoxin as a Mechanistic Model for the [NiFe] Hydrogenases. J Am Chem Soc 2018; 140:10250-10262. [PMID: 30016865 DOI: 10.1021/jacs.8b05194] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Jeffrey W. Slater
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Sean C. Marguet
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Haleigh A. Monaco
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Hannah S. Shafaat
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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19
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The structure of hydrogenase-2 from Escherichia coli: implications for H 2-driven proton pumping. Biochem J 2018; 475:1353-1370. [PMID: 29555844 PMCID: PMC5902676 DOI: 10.1042/bcj20180053] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/12/2018] [Accepted: 03/16/2018] [Indexed: 01/19/2023]
Abstract
Under anaerobic conditions, Escherichia coli is able to metabolize molecular hydrogen via the action of several [NiFe]-hydrogenase enzymes. Hydrogenase-2, which is typically present in cells at low levels during anaerobic respiration, is a periplasmic-facing membrane-bound complex that functions as a proton pump to convert energy from hydrogen (H2) oxidation into a proton gradient; consequently, its structure is of great interest. Empirically, the complex consists of a tightly bound core catalytic module, comprising large (HybC) and small (HybO) subunits, which is attached to an Fe–S protein (HybA) and an integral membrane protein (HybB). To date, efforts to gain a more detailed picture have been thwarted by low native expression levels of Hydrogenase-2 and the labile interaction between HybOC and HybA/HybB subunits. In the present paper, we describe a new overexpression system that has facilitated the determination of high-resolution crystal structures of HybOC and, hence, a prediction of the quaternary structure of the HybOCAB complex.
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20
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Rewiring of Cyanobacterial Metabolism for Hydrogen Production: Synthetic Biology Approaches and Challenges. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:171-213. [PMID: 30091096 DOI: 10.1007/978-981-13-0854-3_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
With the demand for renewable energy growing, hydrogen (H2) is becoming an attractive energy carrier. Developing H2 production technologies with near-net zero carbon emissions is a major challenge for the "H2 economy." Certain cyanobacteria inherently possess enzymes, nitrogenases, and bidirectional hydrogenases that are capable of H2 evolution using sunlight, making them ideal cell factories for photocatalytic conversion of water to H2. With the advances in synthetic biology, cyanobacteria are currently being developed as a "plug and play" chassis to produce H2. This chapter describes the metabolic pathways involved and the theoretical limits to cyanobacterial H2 production and summarizes the metabolic engineering technologies pursued.
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21
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Greene BL, Vansuch GE, Chica BC, Adams MWW, Dyer RB. Applications of Photogating and Time Resolved Spectroscopy to Mechanistic Studies of Hydrogenases. Acc Chem Res 2017; 50:2718-2726. [PMID: 29083854 DOI: 10.1021/acs.accounts.7b00356] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Rapid and facile redox chemistry is exemplified in nature by the oxidoreductases, the class of enzymes that catalyze electron transfer (ET) from a donor to an acceptor. The key role of oxidoreductases in metabolism and biosynthesis has imposed evolutionary pressure to enhance enzyme efficiency, pushing some toward the diffusion limit. Understanding the detailed molecular mechanisms of these highly optimized enzymes would provide an important foundation for the rational design of catalysts for multielectron chemistry, including fuel production. The hydrogenases (H2ases) are the oxidoreductases that catalyze the most basic electron and proton transfer reactions relevant to fuel production, the interconversion of protons and hydrogen, with kcat > 103 s-1. Thus, they provide a model system for studying the efficiency exhibited by oxidoreductases. Because of the extraordinarily fast catalytic rates of these enzymes, their mechanisms have been difficult to study directly but instead have been inferred from structural and steady-state measurements. Although informative, the kinetic competency of observed equilibrium steps can only be suggested by these methods, not demonstrated, because the fundamental (fast) catalytic steps remain unresolved, resulting in minimal insight regarding the underlying ET and proton transfer (PT) events. Motivated by this gap in understanding, we developed an approach capable of observing elementary ET and PT during such fast enzyme turnover by combining a laser-induced potential jump with time-resolved spectroscopy. The potential jump initiates enzyme turnover by utilizing a short-pulsed laser to release a "caged" electron from a nanomaterial or NAD(P)H, which is then captured by a mediator such as methyl viologen. The subsequent enzyme reduction and turnover are monitored by transient absorption spectroscopy in the visible or mid-IR spectral regions. The method is completely general and in principle can be applied to any catalytic redox reaction. In the case of hydrogenases, time-resolved infrared spectroscopy of the active site CO ligands is particularly informative since the IR frequencies are exquisitely sensitive to the redox and protonation states. Using this methodology, we have developed a description of the catalytic mechanism of the Pyrococcus furiosus [NiFe]-hydrogenase by demonstrating the kinetic and chemical competency of equilibrium states and by invoking new intermediates. Additionally, the pre-steady-state kinetics revealed a distinct role of proton tunneling in concerted electron-proton transfer (EPT) modulated by a conserved glutamic acid residue. Similar multisite EPT processes have been implicated in numerous enzymes but have not been demonstrated explicitly. These methods have also been successfully applied to an electron bifurcating [FeFe]-H2ase from Thermotoga maritima, establishing the kinetic competency of the Hox, Hred, and Hsred intermediates of the [FeFe] enzyme. These results provide fundamental insight on the factors that control low barrier proton and electron flow in enzymes and thus provide a foundation for the rational design of reversible biomimetic catalysts.
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Affiliation(s)
- Brandon L. Greene
- Department
of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Gregory E. Vansuch
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Bryant C. Chica
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Michael W. W. Adams
- Department
of Biochemistry and Molecular Biology, University of Georgia, B122 Life
Sciences Bldg., Athens, Georgia 30602, United States
| | - R. Brian Dyer
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
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22
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Bullock RM, Chambers GM. Frustration across the periodic table: heterolytic cleavage of dihydrogen by metal complexes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:20170002. [PMID: 28739961 PMCID: PMC5540836 DOI: 10.1098/rsta.2017.0002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/12/2017] [Indexed: 06/07/2023]
Abstract
This perspective examines frustrated Lewis pairs (FLPs) in the context of heterolytic cleavage of H2 by transition metal complexes, with an emphasis on molecular complexes bearing an intramolecular Lewis base. FLPs have traditionally been associated with main group compounds, yet many reactions of transition metal complexes support a broader classification of FLPs that includes certain types of transition metal complexes with reactivity resembling main group-based FLPs. This article surveys transition metal complexes that heterolytically cleave H2, which vary in the degree that the Lewis pairs within these systems interact. Many of the examples include complexes bearing a pendant amine functioning as the base with the metal functioning as the hydride acceptor. Consideration of transition metal compounds in the context of FLPs can inspire new innovations and improvements in transition metal catalysis.This article is part of the themed issue 'Frustrated Lewis pair chemistry'.
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Affiliation(s)
- R Morris Bullock
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, PO Box 999, K2-12, Richland, WA 99352, USA
| | - Geoffrey M Chambers
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, PO Box 999, K2-12, Richland, WA 99352, USA
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