1
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Song B, Guo H, Chen Z, Xu Q, Chen L, Bai X. Analysis of landfill leachate promoting efficient application of weathered coal anaerobic fermentation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 273:116151. [PMID: 38412633 DOI: 10.1016/j.ecoenv.2024.116151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 02/29/2024]
Abstract
This research aimed to develop a new method for clean utilization and treatment of landfill leachate and solid waste weathered coal. Landfill leachate and weathered coal were adopted for combined anaerobic fermentation for methane production. The characteristics of microbial community, mechanism of biological methane production, and utilization characteristics of fermentation broth and solid residue for co-fermentation were analyzed through metagenomics, soluble organic matter detection and thermogravimetric (TG) analysis. The obtained results revealed that combined anaerobic fermentation increased methane production by 80.1%. Syntrophomonas, Salipiger, Methanosaeta and Methanothrix were highly correlated. Gene abundances of 2-oxoacid ferredoxin oxidoreductase and enolase were increased in methane conversion pathway mainly by acetic acid. Pyruvate-ferroredoxin oxidoreductase, 2-oxoglutarate synthase and succinate dehydrogenase acetate synthase intensified electron transfer pathways among microorganisms. Fulvic acid, tyrosine and tryptophan contents were high in fermentation broth. Volatile decomposition temperature, ignition point and residual char combustion temperature of residual coal were decreased and combustion was more stable. The obtained results showed that the co-fermentation of landfill leachate and weathered coal improved biological methane gas production, degraded weathered coal and improved combustion performance, which provided a new idea for weathered coal clean utilization.
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Affiliation(s)
- Bo Song
- School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China
| | - Hongyu Guo
- School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China; Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Henan Polytechnic University, Jiaozuo 454000, China.
| | - Zhenhong Chen
- Research Institute of Petroleum Exploration & Development, Beijing 100083, China
| | - Qiang Xu
- General Prospecting Institute of China National Administration of Coal Geology, Beijing 100039,China
| | - Linyong Chen
- College of Computer Science and Technology, Henan Polytechnic University, Jiaozuo 454000, China
| | - Xiujia Bai
- General Prospecting Institute of China National Administration of Coal Geology, Beijing 100039,China
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2
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Zhang Z, Bera S, Fan C, Hu X. Streamlined Alkylation via Nickel-Hydride-Catalyzed Hydrocarbonation of Alkenes. J Am Chem Soc 2022; 144:7015-7029. [PMID: 35413202 DOI: 10.1021/jacs.1c13482] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Compounds rich in sp3-hybridized carbons are desirable in drug discovery. Nickel-catalyzed hydrocarbonation of alkenes is a potentially efficient method to synthesize these compounds. By using abundant, readily available, and stable alkenes as pro-nucleophiles, these reactions can have broad scope and high functional group tolerance. However, this methodology is still in an early stage of development, as the first efficient examples were reported only in 2016. Herein, we summarize the progress of this emerging field, with an emphasis on enantioselective reactions. We highlight major developments, critically discuss a wide range of possible mechanisms, and offer our perspective of the state and challenges of the field. We hope this Perspective will stimulate future works in this area, making the methodology widely applicable in organic synthesis.
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Affiliation(s)
- Zhikun Zhang
- Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL-ISIC-LSCI, BCH 3305, Lausanne, CH 1015 Switzerland
| | - Srikrishna Bera
- Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL-ISIC-LSCI, BCH 3305, Lausanne, CH 1015 Switzerland
| | - Chao Fan
- Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL-ISIC-LSCI, BCH 3305, Lausanne, CH 1015 Switzerland
| | - Xile Hu
- Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL-ISIC-LSCI, BCH 3305, Lausanne, CH 1015 Switzerland
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3
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Antil N, Kumar A, Akhtar N, Newar R, Begum W, Dwivedi A, Manna K. Aluminum Metal–Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis. ACS Catal 2021. [DOI: 10.1021/acscatal.0c04379] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Neha Antil
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Ajay Kumar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Naved Akhtar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Rajashree Newar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Wahida Begum
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Ashutosh Dwivedi
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Kuntal Manna
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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4
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Pribanic B, Trincado M, Eiler F, Vogt M, Comas‐Vives A, Grützmacher H. Hydrogenolysis of Polysilanes Catalyzed by Low‐Valent Nickel Complexes. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201907525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Bruno Pribanic
- Department of Chemistry and Applied Biosciences ETH Zürich 8093 Zürich Switzerland
| | - Monica Trincado
- Department of Chemistry and Applied Biosciences ETH Zürich 8093 Zürich Switzerland
| | - Frederik Eiler
- Department of Chemistry and Applied Biosciences ETH Zürich 8093 Zürich Switzerland
| | - Matthias Vogt
- Universität Bremen Fachbereich 2 Biologie/Chemie Institut für Anorganische Chemie und Kristallographie Leobenerstr. 7 28359 Bremen Germany
| | - Aleix Comas‐Vives
- Chemistry Department Universitat Autònoma de Barcelona Cerdanyola del Vallès 08193 Bellaterra Catalonia Spain
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences ETH Zürich 8093 Zürich Switzerland
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5
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Pribanic B, Trincado M, Eiler F, Vogt M, Comas-Vives A, Grützmacher H. Hydrogenolysis of Polysilanes Catalyzed by Low-Valent Nickel Complexes. Angew Chem Int Ed Engl 2020; 59:15603-15609. [PMID: 32049402 DOI: 10.1002/anie.201907525] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Indexed: 11/11/2022]
Abstract
The dehydrogenation of organosilanes (Rx SiH4-x ) under the formation of Si-Si bonds is an intensively investigated process leading to oligo- or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si-Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo- and polysilanes that is highly selective and proceeds under mild conditions. New low-valent nickel hydride complexes are used as catalysts and secondary silanes, RR'SiH2 , are obtained as products in high purity.
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Affiliation(s)
- Bruno Pribanic
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Monica Trincado
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Frederik Eiler
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Matthias Vogt
- Universität Bremen, Fachbereich 2 Biologie/Chemie, Institut für Anorganische Chemie und Kristallographie, Leobenerstr. 7, 28359, Bremen, Germany
| | - Aleix Comas-Vives
- Chemistry Department, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Bellaterra, Catalonia, Spain
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
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6
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Nickel(II)‐Mediated Reversible Thiolate/Disulfide Conversion as a Mimic for a Key Step of the Catalytic Cycle of Methyl‐Coenzyme M Reductase. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Bhandari A, Mishra S, Maji RC, Kumar A, Olmstead MM, Patra AK. Nickel(II)‐Mediated Reversible Thiolate/Disulfide Conversion as a Mimic for a Key Step of the Catalytic Cycle of Methyl‐Coenzyme M Reductase. Angew Chem Int Ed Engl 2020; 59:9177-9185. [DOI: 10.1002/anie.202001363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Indexed: 01/22/2023]
Affiliation(s)
- Anirban Bhandari
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Saikat Mishra
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Ram Chandra Maji
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Akhilesh Kumar
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 India
| | | | - Apurba K. Patra
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
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8
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Ortega DE, Cortés-Arriagada D, Trofymchuk OS, Nachtigall FM, Santos LS, Rojas RS, Toro-Labbé A. Mechanistic study of the competitiveness between branched and linear polyethylene production on N-arylcyano-β-diketiminate nickel hydride. Polym Chem 2020. [DOI: 10.1039/d0py01027h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper provides a guide to identify and understand the mechanistic origin of the catalytic activity and selectivity in the production of linear and branched polyethylene through a nickel hydride catalyst.
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Affiliation(s)
- Daniela E. Ortega
- Centro Integrativo de Biología y Química Aplicada (CIBQA)
- Universidad Bernardo O'Higgins
- Santiago 8370854
- Chile
- Laboratorio de Química Teórica Computacional (QTC)
| | - Diego Cortés-Arriagada
- Programa Institucional de Fomento a la Investigación
- Desarrollo e Innovación. Universidad Tecnológica Metropolitana
- Santiago
- Chile
| | | | - Fabiane M. Nachtigall
- Instituto de Ciencias Químicas Aplicadas
- Universidad Autónoma de Chile
- Talca 3467987
- Chile
| | - Leonardo S. Santos
- Instituto de Química de Recursos Naturales
- Universidad de Talca
- Talca
- Chile
| | - René S. Rojas
- Laboratorio de Química Inorgánica
- Facultad de Química y de Farmacia
- Pontificia Universidad Católica de Chile
- Santiago 7820436
- Chile
| | - Alejandro Toro-Labbé
- Laboratorio de Química Teórica Computacional (QTC)
- Facultad de Química y de Farmacia
- Pontificia Universidad Católica de Chile
- Santiago 7820436
- Chile
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9
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Abstract
The advancements of quantum chemical methods and computer power allow detailed mechanistic investigations of metalloenzymes. In particular, both quantum chemical cluster and combined QM/MM approaches have been used, which have been proven to successfully complement experimental studies. This review starts with a brief introduction of nickel-dependent enzymes and then summarizes theoretical studies on the reaction mechanisms of these enzymes, including NiFe hydrogenase, methyl-coenzyme M reductase, nickel CO dehydrogenase, acetyl CoA synthase, acireductone dioxygenase, quercetin 2,4-dioxygenase, urease, lactate racemase, and superoxide dismutase.
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10
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Thauer RK. Methyl (Alkyl)-Coenzyme M Reductases: Nickel F-430-Containing Enzymes Involved in Anaerobic Methane Formation and in Anaerobic Oxidation of Methane or of Short Chain Alkanes. Biochemistry 2019; 58:5198-5220. [PMID: 30951290 PMCID: PMC6941323 DOI: 10.1021/acs.biochem.9b00164] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Methyl-coenzyme
M reductase (MCR) catalyzes the methane-forming
step in methanogenic archaea. The active enzyme harbors the nickel(I)
hydrocorphin coenzyme F-430 as a prosthetic group and catalyzes the
reversible reduction of methyl-coenzyme M (CH3–S-CoM)
with coenzyme B (HS-CoM) to methane and CoM-S–S-CoB. MCR is
also involved in anaerobic methane oxidation in reverse of methanogenesis
and most probably in the anaerobic oxidation of ethane, propane, and
butane. The challenging question is how the unreactive CH3–S thioether bond in methyl-coenzyme M and the even more unreactive
C–H bond in methane and the other hydrocarbons are anaerobically
cleaved. A key to the answer is the negative redox potential (Eo′) of the Ni(II)F-430/Ni(I)F-430 couple
below −600 mV and the radical nature of Ni(I)F-430. However,
the negative one-electron redox potential is also the Achilles heel
of MCR; it makes the nickel enzyme one of the most O2-sensitive
enzymes known to date. Even under physiological conditions, the Ni(I)
in MCR is oxidized to the Ni(II) or Ni(III) states, e.g., when in
the cells the redox potential (E′) of the
CoM-S–S-CoB/HS-CoM and HS-CoB couple (Eo′ = −140 mV) gets too high. Methanogens therefore
harbor an enzyme system for the reactivation of inactivated MCR in
an ATP-dependent reduction reaction. Purification of active MCR in
the Ni(I) oxidation state is very challenging and has been achieved
in only a few laboratories. This perspective reviews the function,
structure, and properties of MCR, what is known and not known about
the catalytic mechanism, how the inactive enzyme is reactivated, and
what remains to be discovered.
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Affiliation(s)
- Rudolf K Thauer
- Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Strasse 10 , Marburg 35043 , Germany
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11
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Chalkley MJ, Oyala PH, Peters JC. Cp* Noninnocence Leads to a Remarkably Weak C–H Bond via Metallocene Protonation. J Am Chem Soc 2019; 141:4721-4729. [DOI: 10.1021/jacs.9b00193] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Matthew J. Chalkley
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
| | - Paul H. Oyala
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
| | - Jonas C. Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
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12
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Haeri HH, Duraisamy R, Harmgarth N, Liebing P, Lorenz V, Hinderberger D, Edelmann FT. Electronic and Geometric Structures of Paramagnetic Diazadiene Complexes of Lithium and Sodium. ChemistryOpen 2018; 7:701-708. [PMID: 30202705 PMCID: PMC6123648 DOI: 10.1002/open.201800114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Indexed: 11/08/2022] Open
Abstract
The electronic and molecular structures of the lithium and sodium complexes of 1,4-bis(2,6-diisopropylphenyl)-2,3-dimethyl-1,4-diazabutadiene (Me2DADDipp) were fully characterized by using a multi-frequency electron paramagnetic resonance (EPR) spectroscopy approach and crystallography, together with density functional theory (DFT) calculations. EPR measurements, using T1 relaxation-time-filtered pulse EPR spectroscopy, revealed the diagonal elements of the A and g tensors for the metal and ligand sites. It was found that the central metals in the lithium complexes had sizable contributions to the SOMO, whereas this contribution was less strongly observed for the sodium complex. Such strong contributions were attributed to structural specifications (e.g. geometrical data and atomic size) rather than electronic effects.
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Affiliation(s)
- Haleh H. Haeri
- Institute of ChemistryMartin Luther University Halle-WittenbergVon-Danckelmann-Platz 406120HalleGermany
| | - Ramesh Duraisamy
- Institute of ChemistryOtto-von-Guericke UniversityMagdeburg39106Germany
| | - Nicole Harmgarth
- Institute of ChemistryOtto-von-Guericke UniversityMagdeburg39106Germany
| | - Phil Liebing
- Laboratory for Inorganic ChemistryETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
| | - Volker Lorenz
- Institute of ChemistryOtto-von-Guericke UniversityMagdeburg39106Germany
| | - Dariush Hinderberger
- Institute of ChemistryMartin Luther University Halle-WittenbergVon-Danckelmann-Platz 406120HalleGermany
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13
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Ragsdale SW, Raugei S, Ginovska B, Wongnate T. Biochemistry of Methyl-Coenzyme M Reductase. THE BIOLOGICAL CHEMISTRY OF NICKEL 2017. [DOI: 10.1039/9781788010580-00149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Methanogens are masters of CO2 reduction. They conserve energy by coupling H2 oxidation to the reduction of CO2 to CH4, the primary constituent of natural gas. They also generate methane by the reduction of acetic acid, methanol, methane thiol, and methylamines. Methanogens produce 109 tons of methane per year and are the major source of the earth’s atmospheric methane. Reverse methanogenesis or anaerobic methane oxidation, which is catalyzed by methanotrophic archaea living in consortia among bacteria that can act as an electron acceptor, is responsible for annual oxidation of 108 tons of methane to CO2. This chapter briefly describes the overall process of methanogenesis and then describes the enzymatic mechanism of the nickel enzyme, methyl-CoM reductase (MCR), the key enzyme in methane synthesis and oxidation. MCR catalyzes the formation of methane and the heterodisulfide (CoBSSCoM) from methyl-coenzyme M (methyl-CoM) and coenzyme B (HSCoB). Uncovering the mechanistic and molecular details of MCR catalysis is critical since methane is an abundant and important fuel and is the second (to CO2) most prevalent greenhouse gas.
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Affiliation(s)
- Stephen W. Ragsdale
- Department of Biological Chemistry, University of Michigan Medical School 1150 W. Medical Center Dr., 5301 MSRB III Ann Arbor MI 48109-0606 USA
| | - Simone Raugei
- Physical Sciences Division, Pacific Northwest National Laboratory, Post Office Box 999 K1-83 Richland WA 99352 USA
| | - Bojana Ginovska
- Physical Sciences Division, Pacific Northwest National Laboratory, Post Office Box 999 K1-83 Richland WA 99352 USA
| | - Thanyaporn Wongnate
- School of Bioresources and Technology and Excellent Center of Waste Utilization and Management (ECoWaste), King Mongkut's University of Technology Thonburi Bangkhunthian, Bangkok 10140 Thailand
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14
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Pelties S, Carter E, Folli A, Mahon MF, Murphy DM, Whittlesey MK, Wolf R. Influence of Ring-Expanded N-Heterocyclic Carbenes on the Structures of Half-Sandwich Ni(I) Complexes: An X-ray, Electron Paramagnetic Resonance (EPR), and Electron Nuclear Double Resonance (ENDOR) Study. Inorg Chem 2016; 55:11006-11017. [PMID: 27731984 DOI: 10.1021/acs.inorgchem.6b01540] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Potassium graphite reduction of the half-sandwich Ni(II) ring-expanded diamino/diamidocarbene complexes CpNi(RE-NHC)Br gave the Ni(I) derivatives CpNi(RE-NHC) (where RE-NHC = 6-Mes (1), 7-Mes (2), 6-MesDAC (3)) in yields of 40%-50%. The electronic structures of paramagnetic 1-3 were investigated by CW X-/Q-band electron paramagnetic resonance (EPR) and Q-band 1H electron nuclear double resonance (ENDOR) spectroscopy. While small variations in the g-values were observed between the diaminocarbene complexes 1 and 2, pronounced changes in the g-values were detected between the almost isostructural species (1) and diamidocarbene species (3). These results highlight the sensitivity of the EPR g-tensor to changes in the electronic structure of the Ni(I) centers generated by incorporation of heteroatom substituents onto the backbone ring positions. Variable-temperature EPR analysis also revealed the presence of a second Ni(I) site in 3. The experimental g-values for these two Ni(I) sites detected by EPR in frozen solutions of 3 are consistent with resolution on the EPR time scale of the disordered components evident in the X-ray crystallographically determined structure and the corresponding density functional theory (DFT)-calculated g-tensor. Q-band 1H ENDOR measurements revealed a small amount of unpaired electron spin density on the Cp rings, consistent with the calculated SOMO of complexes 1-3. The magnitude of the 1H A values for 3 were also notably larger, compared to 1 and 2, again highlighting the influence of the diamidocarbene on the electronic properties of 3.
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Affiliation(s)
- Stefan Pelties
- Institute of Inorganic Chemistry, University of Regensburg , 93040 Regensburg, Germany
| | - Emma Carter
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Andrea Folli
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Mary F Mahon
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, United Kingdom
| | - Damien M Murphy
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Michael K Whittlesey
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, United Kingdom
| | - Robert Wolf
- Institute of Inorganic Chemistry, University of Regensburg , 93040 Regensburg, Germany
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15
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Affiliation(s)
- Nathan A. Eberhardt
- Department
of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
| | - Hairong Guan
- Department
of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
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16
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Wongnate T, Sliwa D, Ginovska B, Smith D, Wolf MW, Lehnert N, Raugei S, Ragsdale SW. The radical mechanism of biological methane synthesis by methyl-coenzyme M reductase. Science 2016; 352:953-8. [PMID: 27199421 DOI: 10.1126/science.aaf0616] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/05/2016] [Indexed: 12/16/2022]
Abstract
Methyl-coenzyme M reductase, the rate-limiting enzyme in methanogenesis and anaerobic methane oxidation, is responsible for the biological production of more than 1 billion tons of methane per year. The mechanism of methane synthesis is thought to involve either methyl-nickel(III) or methyl radical/Ni(II)-thiolate intermediates. We employed transient kinetic, spectroscopic, and computational approaches to study the reaction between the active Ni(I) enzyme and substrates. Consistent with the methyl radical-based mechanism, there was no evidence for a methyl-Ni(III) species; furthermore, magnetic circular dichroism spectroscopy identified the Ni(II)-thiolate intermediate. Temperature-dependent transient kinetics also closely matched density functional theory predictions of the methyl radical mechanism. Identifying the key intermediate in methanogenesis provides fundamental insights to develop better catalysts for producing and activating an important fuel and potent greenhouse gas.
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Affiliation(s)
- Thanyaporn Wongnate
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA
| | - Dariusz Sliwa
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA
| | - Bojana Ginovska
- Physical Sciences Division, Pacific Northwest National Laboratory, Post Office Box 999, K1-83, Richland, WA 99352, USA
| | - Dayle Smith
- Physical Sciences Division, Pacific Northwest National Laboratory, Post Office Box 999, K1-83, Richland, WA 99352, USA
| | - Matthew W Wolf
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Nicolai Lehnert
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Simone Raugei
- Physical Sciences Division, Pacific Northwest National Laboratory, Post Office Box 999, K1-83, Richland, WA 99352, USA
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA.
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18
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Rittle J, McCrory CL, Peters JC. A 10(6)-fold enhancement in N2-binding affinity of an Fe2(μ-H)2 core upon reduction to a mixed-valence Fe(II)Fe(I) state. J Am Chem Soc 2014; 136:13853-62. [PMID: 25184795 PMCID: PMC4183624 DOI: 10.1021/ja507217v] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Indexed: 01/19/2023]
Abstract
Transient hydride ligands bridging two or more iron centers purportedly accumulate on the iron-molybdenum cofactor (FeMoco) of nitrogenase, and their role in the reduction of N2 to NH3 is unknown. One role of these ligands may be to facilitate N2 coordination at an iron site of FeMoco. Herein, we consider this hypothesis and describe the preparation of a series of diiron complexes supported by two bridging hydride ligands. These compounds bind either one or two molecules of N2 depending on the redox state of the Fe2(μ-H)2 unit. An unusual example of a mixed-valent Fe(II)(μ-H)2Fe(I) is described that displays a 10(6)-fold enhancement of N2 binding affinity over its oxidized congener, quantified by spectroscopic and electrochemical techniques. Furthermore, these compounds show promise as functional models of nitrogenase as substantial amounts of NH3 are produced upon exposure to proton and electron equivalents. The Fe(μ-H)Fe(N2) sub-structure featured herein was previously unknown. This subunit may be relevant to consider in nitrogenases during turnover.
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Affiliation(s)
- Jonathan Rittle
- Division
of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Charles
C. L. McCrory
- Division
of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Jonas C. Peters
- Division
of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
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19
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Poulten RC, López I, Llobet A, Mahon MF, Whittlesey MK. Stereoelectronic Effects in C–H Bond Oxidation Reactions of Ni(I) N-Heterocyclic Carbene Complexes. Inorg Chem 2014; 53:7160-9. [DOI: 10.1021/ic500213h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Rebecca C. Poulten
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K
| | - Isidoro López
- Institute of Chemical Research of Catalonia (ICIQ), Avinguda Paisos Catalans 16, E-43007 Tarragona, Spain
| | - Antoni Llobet
- Institute of Chemical Research of Catalonia (ICIQ), Avinguda Paisos Catalans 16, E-43007 Tarragona, Spain
| | - Mary F. Mahon
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K
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20
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Chen SL, Blomberg MRA, Siegbahn PEM. An investigation of possible competing mechanisms for Ni-containing methyl–coenzyme M reductase. Phys Chem Chem Phys 2014; 16:14029-35. [DOI: 10.1039/c4cp01483a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Biochemistry of methyl-coenzyme M reductase: the nickel metalloenzyme that catalyzes the final step in synthesis and the first step in anaerobic oxidation of the greenhouse gas methane. Met Ions Life Sci 2014; 14:125-45. [PMID: 25416393 DOI: 10.1007/978-94-017-9269-1_6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Methane, the major component of natural gas, has been in use in human civilization since ancient times as a source of fuel and light. Methanogens are responsible for synthesis of most of the methane found on Earth. The enzyme responsible for catalyzing the chemical step of methanogenesis is methyl-coenzyme M reductase (MCR), a nickel enzyme that contains a tetrapyrrole cofactor called coenzyme F430, which can traverse the Ni(I), (II), and (III) oxidation states. MCR and methanogens are also involved in anaerobic methane oxidation. This review describes structural, kinetic, and computational studies aimed at elucidating the mechanism of MCR. Such studies are expected to impact the many ramifications of methane in our society and environment, including energy production and greenhouse gas warming.
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22
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Zhou Y, Dorchak AE, Ragsdale SW. In vivo activation of methyl-coenzyme M reductase by carbon monoxide. Front Microbiol 2013; 4:69. [PMID: 23554601 PMCID: PMC3612591 DOI: 10.3389/fmicb.2013.00069] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/11/2013] [Indexed: 12/21/2022] Open
Abstract
Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the rate-limiting and final step in methane biosynthesis. Using coenzyme B as the two-electron donor, MCR reduces methyl-coenzyme M (CH3-SCoM) to methane and the mixed disulfide, CoBS-SCoM. MCR contains an essential redox-active nickel tetrahydrocorphinoid cofactor, Coenzyme F430, at its active site. The active form of the enzyme (MCRred1) contains Ni(I)-F430. Rapid and efficient conversion of MCR to MCRred1 is important for elucidating the enzymatic mechanism, yet this reduction is difficult because the Ni(I) state is subject to oxidative inactivation. Furthermore, no in vitro methods have yet been described to convert Ni(II) forms into MCRred1. Since 1991, it has been known that MCRred1 from Methanothermobacter marburgensis can be generated in vivo when cells are purged with 100% H2. Here we show that purging cells or cell extracts with CO can also activate MCR. The rate of in vivo activation by CO is about 15 times faster than by H2 (130 and 8 min-1, respectively) and CO leads to twofold higher MCRred1 than H2. Unlike H2-dependent activation, which exhibits a 10-h lag time, there is no lag for CO-dependent activation. Based on cyanide inhibition experiments, carbon monoxide dehydrogenase is required for the CO-dependent activation. Formate, which also is a strong reductant, cannot activate MCR in M. marburgensis in vivo.
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Affiliation(s)
- Yuzhen Zhou
- Department of Biological Chemistry, University of Michigan Medical School, University of Michigan Ann Arbor, MI, USA
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23
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Plois M, Hujo W, Grimme S, Schwickert C, Bill E, de Bruin B, Pöttgen R, Wolf R. Offenschalige Polyhydridokomplexe von 3d-Metallionen mit demfac-[RuH3(PR3)3]−-Baustein. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201205209] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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24
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Plois M, Hujo W, Grimme S, Schwickert C, Bill E, de Bruin B, Pöttgen R, Wolf R. Open-Shell First-Row Transition-Metal Polyhydride Complexes Based on thefac-[RuH3(PR3)3]−Building Block. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/anie.201205209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Kinney RA, Saouma CT, Peters JC, Hoffman BM. Modeling the signatures of hydrides in metalloenzymes: ENDOR analysis of a Di-iron Fe(μ-NH)(μ-H)Fe core. J Am Chem Soc 2012; 134:12637-47. [PMID: 22823933 PMCID: PMC3433054 DOI: 10.1021/ja303739g] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The application of 35 GHz pulsed EPR and ENDOR spectroscopies has established that the biomimetic model complex L(3)Fe(μ-NH)(μ-H)FeL(3) (L(3) = [PhB(CH(2)PPh(2))(3)](-)) complex, 3, is a novel S = (1)/(2) type-III mixed-valence di-iron II/III species, in which the unpaired electron is shared equally between the two iron centers. (1,2)H and (14,15)N ENDOR measurements of the bridging imide are consistent with an allyl radical molecular orbital model for the two bridging ligands. Both the (μ-H) and the proton of the (μ-NH) of the crystallographically characterized 3 show the proposed signature of a 'bridging' hydride that is essentially equidistant between two 'anchor' metal ions: a rhombic dipolar interaction tensor, T ≈ [T, -T, 0]. The point-dipole model for describing the anisotropic interaction of a bridging H as the sum of the point-dipole couplings to the 'anchor' metal ions reproduces this signature with high accuracy, as well as the axial tensor of a terminal hydride, T ≈ [-T, -T, 2T], thus validating both the model and the signatures. This validation in turn lends strong support to the assignment, based on such a point-dipole analysis, that the molybdenum-iron cofactor of nitrogenase contains two [Fe-H(-)-Fe] bridging-hydride fragments in the catalytic intermediate that has accumulated four reducing equivalents (E(4)). Analysis further reveals a complementary similarity between the isotropic hyperfine couplings for the bridging hydrides in 3 and E(4). This study provides a foundation for spectroscopic study of hydrides in a variety of reducing metalloenzymes in addition to nitrogenase.
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Affiliation(s)
- R Adam Kinney
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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26
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Saraev VV, Kraikivskii PB, Bocharova VV, Matveev DA. Role of paramagnetic Ni(I) and Ni(III) complexes in catalytic reactions of unsaturated hydrocarbons. KINETICS AND CATALYSIS 2012. [DOI: 10.1134/s0023158412040106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Chen SL, Blomberg MRA, Siegbahn PEM. How Is Methane Formed and Oxidized Reversibly When Catalyzed by Ni-Containing Methyl-Coenzyme M Reductase? Chemistry 2012; 18:6309-15. [DOI: 10.1002/chem.201200274] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Indexed: 11/07/2022]
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28
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Wang Z, Lin P, Baker GA, Stetter J, Zeng X. Ionic Liquids as Electrolytes for the Development of a Robust Amperometric Oxygen Sensor. Anal Chem 2011; 83:7066-73. [DOI: 10.1021/ac201235w] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhe Wang
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Peiling Lin
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Gary A. Baker
- Department of Chemistry, University of Missouri−Columbia, Columbia, Missouri 65211, United States
| | - Joseph Stetter
- KWJ Engineering Incorporated, 8440 Central Avenue [Suite 2B or 2D], Newark, California 94560, United States
| | - Xiangqun Zeng
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
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29
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Scheller S, Goenrich M, Mayr S, Thauer RK, Jaun B. Intermediates in the catalytic cycle of methyl coenzyme M reductase: isotope exchange is consistent with formation of a σ-alkane-nickel complex. Angew Chem Int Ed Engl 2011; 49:8112-5. [PMID: 20857468 DOI: 10.1002/anie.201003214] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Silvan Scheller
- Laboratory of Organic Chemistry, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
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30
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Dey M, Li X, Kunz RC, Ragsdale SW. Detection of Organometallic and Radical Intermediates in the Catalytic Mechanism of Methyl-Coenzyme M Reductase Using the Natural Substrate Methyl-Coenzyme M and a Coenzyme B Substrate Analogue. Biochemistry 2010; 49:10902-11. [DOI: 10.1021/bi101562m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mishtu Dey
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xianghui Li
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ryan C. Kunz
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Stephen W. Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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31
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Cedervall PE, Dey M, Pearson AR, Ragsdale SW, Wilmot CM. Structural insight into methyl-coenzyme M reductase chemistry using coenzyme B analogues . Biochemistry 2010; 49:7683-93. [PMID: 20707311 DOI: 10.1021/bi100458d] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methyl-coenzyme M reductase (MCR) catalyzes the final and rate-limiting step in methane biogenesis: the reduction of methyl-coenzyme M (methyl-SCoM) by coenzyme B (CoBSH) to methane and a heterodisulfide (CoBS-SCoM). Crystallographic studies show that the active site is deeply buried within the enzyme and contains a highly reduced nickel-tetrapyrrole, coenzyme F(430). Methyl-SCoM must enter the active site prior to CoBSH, as species derived from methyl-SCoM are always observed bound to the F(430) nickel in the deepest part of the 30 A long substrate channel that leads from the protein surface to the active site. The seven-carbon mercaptoalkanoyl chain of CoBSH binds within a 16 A predominantly hydrophobic part of the channel close to F(430), with the CoBSH thiolate lying closest to the nickel at a distance of 8.8 A. It has previously been suggested that binding of CoBSH initiates catalysis by inducing a conformational change that moves methyl-SCoM closer to the nickel promoting cleavage of the C-S bond of methyl-SCoM. In order to better understand the structural role of CoBSH early in the MCR mechanism, we have determined crystal structures of MCR in complex with four different CoBSH analogues: pentanoyl, hexanoyl, octanoyl, and nonanoyl derivatives of CoBSH (CoB(5)SH, CoB(6)SH, CoB(8)SH, and CoB(9)SH, respectively). The data presented here reveal that the shorter CoB(5)SH mercaptoalkanoyl chain overlays with that of CoBSH but terminates two units short of the CoBSH thiolate position. In contrast, the mercaptoalkanoyl chain of CoB(6)SH adopts a different conformation, such that its thiolate is coincident with the position of the CoBSH thiolate. This is consistent with the observation that CoB(6)SH is a slow substrate. A labile water in the substrate channel was found to be a sensitive indicator for the presence of CoBSH and HSCoM. The longer CoB(8)SH and CoB(9)SH analogues can be accommodated in the active site through exclusion of this water. These analogues react with Ni(III)-methyl, a proposed MCR catalytic intermediate of methanogenesis. The CoB(8)SH thiolate is 2.6 A closer to the nickel than that of CoBSH, but the additional carbon of CoB(9)SH only decreases the nickel thiolate distance a further 0.3 A. Although the analogues do not induce any structural changes in the substrate channel, the thiolates appear to preferentially bind at two distinct positions in the channel, one being the previously observed CoBSH thiolate position and the other being at a hydrophobic annulus of residues that lines the channel proximal to the nickel.
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Affiliation(s)
- Peder E Cedervall
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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32
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Scheller S, Goenrich M, Mayr S, Thauer RK, Jaun B. Zwischenprodukte im Katalysezyklus von Methyl-Coenzym-M- Reduktase: Das Muster des Isotopenaustauschs ist in Einklang mit der Bildung eines σ-Alkan-Nickel-Komplexes. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201003214] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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33
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Li X, Telser J, Kunz RC, Hoffman BM, Gerfen G, Ragsdale SW. Observation of organometallic and radical intermediates formed during the reaction of methyl-coenzyme M reductase with bromoethanesulfonate. Biochemistry 2010; 49:6866-76. [PMID: 20597483 DOI: 10.1021/bi100650m] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the final step of methane formation, in which methyl-coenzyme M (2-methylthioethanesulfonate, methyl-SCoM) is reduced with coenzyme B (N-(7-mercaptoheptanoyl)threonine phosphate, CoBSH) to form methane and the heterodisulfide CoBS-SCoM. The active dimeric form of MCR contains two Ni(I)-F(430) prosthetic groups, one in each monomer. This report describes studies of the reaction of the active Ni(I) state of MCR (MCR(red1)) with BES (2-bromoethanesulfonate) and CoBSH or its analogue, CoB(6)SH (N-(6-mercaptohexanoyl)threonine phosphate), by transient kinetic measurements using EPR and UV-visible spectroscopy and by global fits of the data. This reaction is shown to lead to the formation of three intermediates, the first of which is assigned as an alkyl-Ni(III) species that forms as the active Ni(I)-MCR(red1) state of the enzyme decays. Subsequently, a radical (MCR(BES) radical) is formed that was characterized by multifrequency electron paramagnetic resonance (EPR) studies at X- ( approximately 9 GHz), Q- ( approximately 35 GHz), and D- ( approximately 130 GHz) bands and by electron-nuclear double resonance (ENDOR) spectroscopy. The MCR(BES) radical is characterized by g-values at 2.00340 and 1.99832 and includes a strongly coupled nonexchangeable proton with a hyperfine coupling constant of 50 MHz. Based on transient kinetic measurements, the formation and decay of the radical coincide with a species that exhibits absorption peaks at 426 and 575 nm. Isotopic substitution, multifrequency EPR, and ENDOR spectroscopic experiments rule out the possibility that MCR(BES) is a tyrosyl radical and indicate that if a tyrosyl radical is formed during the reaction, it does not accumulate to detectable levels. The results provide support for a hybrid mechanism of methanogenesis by MCR that includes both alkyl-Ni and radical intermediates.
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Affiliation(s)
- Xianghui Li
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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34
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Van Heuvelen KM, Cho J, Dingee T, Riordan CG, Brunold TC. Spectroscopic and computational studies of a series of high-spin Ni(II) thiolate complexes. Inorg Chem 2010; 49:6535-44. [PMID: 20565082 DOI: 10.1021/ic100362q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structures of a series of high-spin Ni(II)-thiolate complexes of the form [PhTt(tBu)]Ni(SR) (R = CPh(3), 2; C(6)F(5), 3; C(6)H(5), 4; PhTt(tBu) = phenyltris((tert-butylthio)methyl)borate) have been characterized using a combined spectroscopic and computational approach. Resonance Raman (rR) spectroscopic data reveal that the nu(Ni-SR) vibrational feature occurs between 404 and 436 cm(-1) in these species. The corresponding rR excitation profiles display a striking de-enhancement behavior because of interference effects involving energetically proximate electronic excited states. These data were analyzed in the framework of time-dependent Heller theory to obtain quantitative insight into excited state nuclear distortions. The electronic absorption and magnetic circular dichroism spectra of 2-4 are characterized by numerous charge transfer (CT) transitions. The dominant absorption feature, which occurs at approximately 18,000 cm(-1) in all three complexes, is assigned as a thiolate-to-Ni CT transition involving molecular orbitals that are of pi-symmetry with respect to the Ni-S bond, reminiscent of the characteristic absorption feature of blue copper proteins. Density functional theory computational data provide molecular orbital descriptions for 2-4 and allow for detailed assignments of the key spectral features. A comparison of the results obtained in this study to those reported for similar Ni-thiolate species reveals that the supporting ligand plays a secondary role in determining the spectroscopic properties, as the electronic structure is primarily determined by the metal-thiolate bonding interaction.
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35
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Ebner S, Jaun B, Goenrich M, Thauer RK, Harmer J. Binding of coenzyme B induces a major conformational change in the active site of methyl-coenzyme M reductase. J Am Chem Soc 2010; 132:567-75. [PMID: 20014831 DOI: 10.1021/ja906367h] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methyl-coenzyme M reductase (MCR) is the key enzyme in methane formation by methanogenic Archaea. It converts the thioether methyl-coenzyme M and the thiol coenzyme B into methane and the heterodisulfide of coenzyme M and coenzyme B. The catalytic mechanism of MCR and the role of its prosthetic group, the nickel hydrocorphin coenzyme F(430), is still disputed, and no intermediates have been observed so far by fast spectroscopic techniques when the enzyme was incubated with the natural substrates. In the presence of the competitive inhibitor coenzyme M instead of methyl-coenzyme M, addition of coenzyme B to the active Ni(I) state MCR(red1) induces two new species called MCR(red2a) and MCR(red2r) which have been characterized by pulse EPR spectroscopy. Here we show that the two MCR(red2) signals can also be induced by the S-methyl- and the S-trifluoromethyl analogs of coenzyme B. (19)F-ENDOR data for MCR(red2a) and MCR(red2r) induced by S-CF(3)-coenzyme B show that, upon binding of the coenzyme B analog, the end of the 7-thioheptanoyl chain of coenzyme B moves closer to the nickel center of F(430) by more than 2 A as compared to its position in both, the Ni(I) MCR(red1) form and the X-ray structure of the inactive Ni(II) MCR(ox1-silent) form. The finding that the protein is able to undergo a conformational change upon binding of the second substrate helps to explain the dramatic change in the coordination environment induced in the transition from MCR(red1) to MCR(red2) forms and opens the possibility that nickel coordination geometries other than square planar, tetragonal pyramidal, or elongated octahedral might occur in intermediates of the catalytic cycle.
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Affiliation(s)
- Sieglinde Ebner
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
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36
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Cramer CJ, Truhlar DG. Density functional theory for transition metals and transition metal chemistry. Phys Chem Chem Phys 2009; 11:10757-816. [PMID: 19924312 DOI: 10.1039/b907148b] [Citation(s) in RCA: 1063] [Impact Index Per Article: 70.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We introduce density functional theory and review recent progress in its application to transition metal chemistry. Topics covered include local, meta, hybrid, hybrid meta, and range-separated functionals, band theory, software, validation tests, and applications to spin states, magnetic exchange coupling, spectra, structure, reactivity, and catalysis, including molecules, clusters, nanoparticles, surfaces, and solids.
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Affiliation(s)
- Christopher J Cramer
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455-0431, USA.
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37
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38
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Van Doorslaer S, Caretti I, Fallis I, Murphy D. The power of electron paramagnetic resonance to study asymmetric homogeneous catalysts based on transition-metal complexes. Coord Chem Rev 2009. [DOI: 10.1016/j.ccr.2008.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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39
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Kraikivskii PB, Frey M, Bennour HA, Gembus A, Hauptmann R, Svoboda I, Fuess H, Saraev VV, Klein HF. Syntheses and properties of molecular nickel(II) hydride, methyl, and nickel(I) complexes supported by trimethylphosphane and (2-diphenylphosphanyl)thiophenolato and -naphtholato ligands. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.01.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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40
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Saraev VV, Kraikivskii PB, Svoboda I, Kuzakov AS, Jordan RF. Synthesis, molecular structure, and EPR analysis of the three-coordinate Ni(I) complex [Ni(PPh3)3][BF4]. J Phys Chem A 2009; 112:12449-55. [PMID: 18991433 DOI: 10.1021/jp802462x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The compound [Ni(PPh(3))(3)][BF(4)] x BF(3) x OEt(2) was isolated in crystalline form from the olefin oligomerization catalyst system Ni(PPh(3))(4)/BF(3) x OEt(2) and structurally characterized by X-ray diffraction. The influence of vibronic coupling on the EPR parameters of three-coordinate metal complexes with a 3d(9) electronic configuration was investigated within the framework of ligand field theory. Analytical expressions for g-tensor components and isotropic hyperfine coupling constants with ligand nuclei were obtained using first-order perturbation theory. It has been shown that the account of the vibronic interaction in the excited state predicts the existence of three-axial anisotropy of the g-tensor even at the level of first-order perturbation theory; two axes of the g-tensor located in a plane of three-coordinate structure can rotate about the main z axis when a compound is distorted by motion of ligands. It has been shown that in three points of the potential energy surface minimum, for which linear and quadric constants of the vibronic interactions have an identical signs, the HFS isotropic constant from one ligand is larger than HFS constants from the other two; for different vibronic constant signs the ratio between HFS constants varies on opposite. This theoretical researches are in the quality consent with experimental data for a three-coordinate Ni(I) and Cu(II) flat complexes.
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Affiliation(s)
- V V Saraev
- Irkutsk State University, Str. K. Marksa, 1, Irkutsk, 664003, Russia.
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41
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Maly T, Zwicker K, Cernescu A, Brandt U, Prisner TF. New pulsed EPR methods and their application to characterize mitochondrial complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:584-92. [PMID: 19366602 DOI: 10.1016/j.bbabio.2009.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/04/2009] [Accepted: 02/05/2009] [Indexed: 10/21/2022]
Abstract
Electron Paramagnetic Resonance (EPR) spectroscopy is the method of choice to study paramagnetic cofactors that often play an important role as active centers in electron transfer processes in biological systems. However, in many cases more than one paramagnetic species is contributing to the observed EPR spectrum, making the analysis of individual contributions difficult and in some cases impossible. With time-domain techniques it is possible to exploit differences in the relaxation behavior of different paramagnetic species to distinguish between them and separate their individual spectral contribution. Here we give an overview of the use of pulsed EPR spectroscopy to study the iron-sulfur clusters of NADH:ubiquinone oxidoreductase (complex I). While FeS cluster N1 can be studied individually at a temperature of 30 K, this is not possible for FeS cluster N2 due to its severe spectral overlap with cluster N1. In this case Relaxation Filtered Hyperfine (REFINE) spectroscopy can be used to separate the overlapping spectra based on differences in their relaxation behavior.
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Affiliation(s)
- Thorsten Maly
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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42
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Shima S, Thauer RK, Ermler U. Carbon Monoxide as Intrinsic Ligand to Iron in the Active Site of [Fe]-Hydrogenase. METAL-CARBON BONDS IN ENZYMES AND COFACTORS 2009. [DOI: 10.1039/9781847559333-00219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Structural and spectroscopic studies on [Fe]-hydrogenase revealed an active site mononuclear low spin iron coordinated by the Cys176 sulfur, two CO, and the sp2 hybridized nitrogen of a 2-pyridinol compound with back bonding properties similar to those of cyanide. Thus, [Fe]-hydrogenases are endowed with an iron-ligation pattern related to that found in the active site of [NiFe]- and [FeFe]-hydrogenases although the three hydrogenases and the enzymes involved in their posttranslational maturation have evolved independently and although CO and cyanide ligands are not found in any other metallo-enzymes. Obviously, low-spin iron complexed with thiolate(s), CO, and cyanide or a cyanide functional analogue plays an essential role in H2 activation.
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Affiliation(s)
- Seigo Shima
- Max Planck Institute for Terrestrial Microbiology Karl-von-Frisch-Strasse D-35043 Marburg Germany
| | - Rudolf K. Thauer
- Max Planck Institute for Terrestrial Microbiology Karl-von-Frisch-Strasse D-35043 Marburg Germany
| | - Ulrich Ermler
- Max Planck Institute for Biophysics Max-von-Laue-Strasse 3 D-60438 Frankfurt/Main Germany
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Hinderberger D, Ebner S, Mayr S, Jaun B, Reiher M, Goenrich M, Thauer RK, Harmer J. Coordination and binding geometry of methyl-coenzyme M in the red1m state of methyl-coenzyme M reductase. J Biol Inorg Chem 2008; 13:1275-89. [PMID: 18712421 DOI: 10.1007/s00775-008-0417-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 07/27/2008] [Indexed: 10/21/2022]
Abstract
Methane formation in methanogenic Archaea is catalyzed by methyl-coenzyme M reductase (MCR) and takes place via the reduction of methyl-coenzyme M (CH3-S-CoM) with coenzyme B (HS-CoB) to methane and the heterodisulfide CoM-S-S-CoB. MCR harbors the nickel porphyrinoid coenzyme F430 as a prosthetic group, which has to be in the Ni(I) oxidation state for the enzyme to be active. To date no intermediates in the catalytic cycle of MCRred1 (red for reduced Ni) have been identified. Here, we report a detailed characterization of MCRred1m ("m" for methyl-coenzyme M), which is the complex of MCRred1a ("a" for absence of substrate) with CH3-S-CoM. Using continuous-wave and pulse electron paramagnetic resonance spectroscopy in combination with selective isotope labeling (13C and 2H) of CH3-S-CoM, it is shown that CH3-S-CoM binds in the active site of MCR such that its thioether sulfur is weakly coordinated to the Ni(I) of F430. The complex is stable until the addition of the second substrate, HS-CoB. Results from EPR spectroscopy, along with quantum mechanical calculations, are used to characterize the electronic and geometric structure of this complex, which can be regarded as the first intermediate in the catalytic mechanism.
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Affiliation(s)
- Dariush Hinderberger
- Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128, Mainz, Germany.
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