1
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Wilson DWN, Thompson BC, Collauto A, Hooper RX, Knapp CE, Roessler MM, Musgrave RA. Mixed Valence {Ni 2+Ni 1+} Clusters as Models of Acetyl Coenzyme A Synthase Intermediates. J Am Chem Soc 2024; 146:21034-21043. [PMID: 39023163 PMCID: PMC11295191 DOI: 10.1021/jacs.4c06241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 07/20/2024]
Abstract
Acetyl coenzyme A synthase (ACS) catalyzes the formation and deconstruction of the key biological metabolite, acetyl coenzyme A (acetyl-CoA). The active site of ACS features a {NiNi} cluster bridged to a [Fe4S4]n+ cubane known as the A-cluster. The mechanism by which the A-cluster functions is debated, with few model complexes able to replicate the oxidation states, coordination features, or reactivity proposed in the catalytic cycle. In this work, we isolate the first bimetallic models of two hypothesized intermediates on the paramagnetic pathway of the ACS function. The heteroligated {Ni2+Ni1+} cluster, [K(12-crown-4)2][1], effectively replicates the coordination number and oxidation state of the proposed "Ared" state of the A-cluster. Addition of carbon monoxide to [1]- allows for isolation of a dinuclear {Ni2+Ni1+(CO)} complex, [K(12-crown-2)n][2] (n = 1-2), which bears similarity to the "ANiFeC" enzyme intermediate. Structural and electronic properties of each cluster are elucidated by X-ray diffraction, nuclear magnetic resonance, cyclic voltammetry, and UV/vis and electron paramagnetic resonance spectroscopies, which are supplemented by density functional theory (DFT) calculations. Calculations indicate that the pseudo-T-shaped geometry of the three-coordinate nickel in [1]- is more stable than the Y-conformation by 22 kcal mol-1, and that binding of CO to Ni1+ is barrierless and exergonic by 6 kcal mol-1. UV/vis absorption spectroscopy on [2]- in conjunction with time-dependent DFT calculations indicates that the square-planar nickel site is involved in electron transfer to the CO π*-orbital. Further, we demonstrate that [2]- promotes thioester synthesis in a reaction analogous to the production of acetyl coenzyme A by ACS.
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Affiliation(s)
- Daniel W. N. Wilson
- Department
of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, U.K.
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Benedict C. Thompson
- Department
of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, U.K.
| | - Alberto Collauto
- Department
of Chemistry and Centre for Pulse EPR Spectroscopy, Imperial College London, 82 Wood Lane, London W12
0BZ, U.K.
| | - Reagan X. Hooper
- Stanford
PULSE Institute, SLAC National Accelerator
Laboratory, Menlo Park, California 94025, United States
| | - Caroline E. Knapp
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Maxie M. Roessler
- Department
of Chemistry and Centre for Pulse EPR Spectroscopy, Imperial College London, 82 Wood Lane, London W12
0BZ, U.K.
| | - Rebecca A. Musgrave
- Department
of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, U.K.
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2
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Berkefeld A, Roemelt M, Römelt C, Schubert H, Jeschke G. Modulating Effect of Ligand Charge on the Electronic Properties of 2Ni-2S Structures and Implications for Biological 2M-2S Sites. Inorg Chem 2020; 59:17234-17243. [PMID: 33202137 DOI: 10.1021/acs.inorgchem.0c02467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sulfur-bridged bimetallic 2M-2S type structures are essential cofactors that participate in biological long-range electron transport and metabolism. Metal-sulfur bond covalency is a decisive property for inner sphere (through-bond) type electron transfer that dominates in buried or hydrophobic protein environments. This work reports on a combined experimental and computational study of the effect of ligand charge on the electronic structure of a 2Ni-2S model site that adopts the biologically relevant S = 1/2 redox state. Starting out from an isostructural dinickel(1.5+)-dithiophenolate platform with sulfur-bridged tetrahedral Ni sites, η2:η2-μ-coordination of the S = 1/2 [2Ni-2S]+ core to either a neutral π-system or strongly σ-donating cyclohexadienido renders its electronic structure substantially different. Density functional theory analysis corroborates pulse and continuous wave electron paramagnetic resonance data that associate co-ligand charge with the significant change in the mechanism and size of electron-31P nuclear spin hyperfine coupling to a phosphine reporter ligand at each nickel center. An increasing level of charge donation attenuates direct and through-bridge electronic coupling of the metal sites, resulting in a stronger electronic coupling of the 2Ni-2S core to its terminal phosphine donors. Drawing a connection to biological 2M-2S sites, our 2Ni-2S system indicates that a fine balance of intracore and core-protein electronic coupling is key to biological function for which the degree of charge donation by peripheral donors appears to be a significant parameter.
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Affiliation(s)
- Andreas Berkefeld
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Michael Roemelt
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christina Römelt
- Max-Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
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3
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Sun P, Yang D, Li Y, Wang B, Qu J. A bioinspired thiolate-bridged dinickel complex with a pendant amine: synthesis, structure and electrocatalytic properties. Dalton Trans 2020; 49:2151-2158. [PMID: 31994565 DOI: 10.1039/c9dt04493k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
By employing X(CH2CH2S-)2 (X = S, tpdt; X = O, opdt; X = NPh, npdt) as bridging ligands, four thiolate-bridged dinickel complexes supported by phosphine ligands, [(dppe)Ni(μ-1SSS':2SS-tpdt)Ni(dppe)][PF6]2 (1[PF6]2, dppe = Ph2P(CH2)2PPh2), [(dppe)Ni(μ-1SSN:2SS-npdt)Ni(dppe)][PF6]2 (2[PF6]2) and [(dppe)Ni(t-Cl)(μ-1SSX:2SS-C4H8S2X)Ni(dppe)][PF6] (3[PF6], X = S; 4[PF6], X = O) were facilely obtained by the salt metathesis reaction. These four thiolate-bridged dinickel complexes have all been fully characterized by spectroscopic methods and X-ray crystallography. In 2[PF6]2, elongation of the Ni-N bond distance, possibly caused by steric hindrance, indicates that the pendant nitrogen group shuttles between the two nickel centers in solution, which is evidenced by 31P{1H} NMR spectroscopic results. Furthermore, these thiolate-bridged dinickel complexes have all been proved to be electrocatalysts for proton reduction to hydrogen. Notably, complex 2[PF6]2 featuring a pendant amine group in the secondary coordination sphere exhibits the best catalytic activity at a relatively low overpotential.
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Affiliation(s)
- Puhua Sun
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, P.R. China.
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4
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Bhandari A, Chandra Maji R, Mishra S, Kumar A, Barman SK, Das PP, Ghiassi KB, Olmstead MM, Patra AK. Model Complexes for the Nip Site of Acetyl Coenzyme A Synthase/Carbon Monoxide (CO) Dehydrogenase: Structure, Electrochemistry, and CO Reactivity. Inorg Chem 2018; 57:13713-13727. [DOI: 10.1021/acs.inorgchem.8b02276] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anirban Bhandari
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713209, India
| | - Ram Chandra Maji
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713209, India
| | - Saikat Mishra
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713209, India
| | - Akhilesh Kumar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Suman Kumar Barman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Partha Pratim Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Kamran B. Ghiassi
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Marilyn M. Olmstead
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Apurba K. Patra
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713209, India
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5
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Sheng YD, Yu XY, Liu XF. Reactions of metallodithiolate ligand with palladium dichloride bearing monophosphine or diphosphine. Polyhedron 2017. [DOI: 10.1016/j.poly.2017.06.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Kure B, Sano M, Watanabe N, Nakajima T, Tanase T. Synthesis and Reactivity of Thiolate‐Bridged Ni
II
M
I
Heterodinuclear Complexes (M = Rh, Ir) with an S‐Bidentate NiP
2
S
2
Metalloligand. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bunsho Kure
- Department of Chemistry Faculty of Science Nara Women's University Kitauoya‐nishi‐machi 630‐8506 Nara Japan
| | - Mikie Sano
- Department of Chemistry Faculty of Science Nara Women's University Kitauoya‐nishi‐machi 630‐8506 Nara Japan
| | - Natsuki Watanabe
- Department of Chemistry Faculty of Science Nara Women's University Kitauoya‐nishi‐machi 630‐8506 Nara Japan
| | - Takayuki Nakajima
- Department of Chemistry Faculty of Science Nara Women's University Kitauoya‐nishi‐machi 630‐8506 Nara Japan
| | - Tomoaki Tanase
- Department of Chemistry Faculty of Science Nara Women's University Kitauoya‐nishi‐machi 630‐8506 Nara Japan
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7
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Zhao T, Ghosh P, Martinez Z, Liu X, Meng X, Darensbourg MY. Discrete Air-Stable Nickel(II)–Palladium(II) Complexes as Catalysts for Suzuki–Miyaura Reactions. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00176] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tiankun Zhao
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Pokhraj Ghosh
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Zachary Martinez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Xufeng Liu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
- College
of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016, China
| | - Xianggao Meng
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Marcetta Y. Darensbourg
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
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8
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Koch F, Berkefeld A, Schubert H, Grauer C. Redox and Acid-Base Properties of Binuclear 4-Terphenyldithiophenolate Complexes of Nickel. Chemistry 2016; 22:14640-7. [DOI: 10.1002/chem.201603060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Felix Koch
- Institut für Anorganische Chemie; Eberhard Karls Universität Tübingen; Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Andreas Berkefeld
- Institut für Anorganische Chemie; Eberhard Karls Universität Tübingen; Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie; Eberhard Karls Universität Tübingen; Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Claudius Grauer
- Institut für Anorganische Chemie; Eberhard Karls Universität Tübingen; Auf der Morgenstelle 18 72076 Tübingen Germany
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9
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Pinder TA, Montalvo SK, Hsieh CH, Lunsford AM, Bethel RD, Pierce BS, Darensbourg MY. Metallodithiolates as Ligands to Dinitrosyl Iron Complexes: Toward the Understanding of Structures, Equilibria, and Spin Coupling. Inorg Chem 2014; 53:9095-105. [DOI: 10.1021/ic501117f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Tiffany A. Pinder
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Steven K. Montalvo
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Chung-Hung Hsieh
- Department of Chemistry, Tamkang University, New Taipei
City 25157, Taiwan
| | - Allen M. Lunsford
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Ryan D. Bethel
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Brad S. Pierce
- Department of Chemistry and Biochemistry, College of Sciences, The University of Texas at Arlington, Arlington, Texas 76019, United States
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10
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Kure B, Sano M, Nakajima T, Tanase T. Systematic Heterodinuclear Complexes with MM′(μ-meppp) Centers That Tune the Properties of a Nesting Hydride (M = Ni, Pd, Pt; M′ = Rh, Ir; H2meppp = meso-1,3-Bis[(mercaptoethyl)phenylphosphino]propane). Organometallics 2014. [DOI: 10.1021/om500410f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Bunsho Kure
- Department of Chemistry,
Faculty of Science, Nara Women’s University, Kitauoya-nishi-machi, Nara 630-8506, Japan
| | - Mikie Sano
- Department of Chemistry,
Faculty of Science, Nara Women’s University, Kitauoya-nishi-machi, Nara 630-8506, Japan
| | - Takayuki Nakajima
- Department of Chemistry,
Faculty of Science, Nara Women’s University, Kitauoya-nishi-machi, Nara 630-8506, Japan
| | - Tomoaki Tanase
- Department of Chemistry,
Faculty of Science, Nara Women’s University, Kitauoya-nishi-machi, Nara 630-8506, Japan
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11
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Zimmerman JR, Smucker BW, Dain RP, Vanstipdonk MJ, Eichhorn DM. Tridentate N(2)S ligand from 2,2'-dithiodibenzaldehyde and N,N-dimethylethylenediamine: Synthesis, structure, and characterization of a Ni(II) complex with relevance to Ni Superoxide Dismutase. Inorganica Chim Acta 2011; 373:54-61. [PMID: 21666847 PMCID: PMC3110705 DOI: 10.1016/j.ica.2011.03.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Nickel Superoxide Dismutase (NiSOD) and the A-cluster of Carbon Monoxide Dehydrogenase/Acetyl Coenzyme A Synthase (CODH/ACS) both feature active sites with Ni coordinated by thiolate and amide donors. It is likely that the particular set of donors is important in tuning the redox potential of the Ni center(s). We report herein an expansion of our efforts involving the use of 2,2'-dithiodibenzaldehyde (DTDB) as a synthon for metal-thiolate complexes to reactions with Ni complexes of N,N-dimethylethylenediamine (dmen). In the presence of coordinating counterions, these reactions result in monomeric square-planar complexes of the tridentate N(2)S donor ligand derived from the Schiff-base condensation of dmen and DTDB. In the absence of a coordinating counterion, we have isolated a Ni(II) complex with an asymmetric N(2)S(2) donor set involving one amine and one imine N donor in addition to two thiolate donors. This latter complex is discussed with respect to its relevance to the active site of NiSOD.
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Affiliation(s)
- Joshua R Zimmerman
- Department of Chemistry, Wichita State University, Wichita, KS 67260-0051
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12
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Mathrubootham V, Thomas J, Staples R, McCraken J, Shearer J, Hegg EL. Bisamidate and mixed amine/amidate NiN2S2 complexes as models for nickel-containing acetyl coenzyme A synthase and superoxide dismutase: an experimental and computational study. Inorg Chem 2010; 49:5393-406. [PMID: 20507077 PMCID: PMC2898278 DOI: 10.1021/ic9023053] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distal nickel site of acetyl-CoA synthase (Ni(d)-ACS) and reduced nickel superoxide dismutase (Ni-SOD) display similar square-planar Ni(II)N(2)S(2) coordination environments. One difference between these two sites, however, is that the nickel ion in Ni-SOD contains a mixed amine/amidate coordination motif while the Ni(d) site in Ni-ACS contains a bisamidate coordination motif. To provide insight into the consequences of the different coordination environments on the properties of the Ni ions, we systematically examined two square-planar Ni(II)N(2)S(2) complexes, one with bisthiolate-bisamidate ligation (Et(4)N)(2)(Ni(L1)).2H(2)O (2) [H(4)L1 = N-(2-mercaptoacetyl)-N'-(2-mercaptoethyl)glycinamide] and another with bisthiolate-amine/amidate ligation K(Ni(HL2)) (3) [H(4)L2 = N-(2''-mercaptoethyl)-2-((2'-mercaptoethyl)amino)acetamide]. Although these two complexes differ only by a single amine versus amidate ligand, their chemical properties are quite different. The stronger in-plane ligand field in the bisamidate complex (Ni(II)(L1))(2-) (2) results in an increase in the energies of the d --> d transitions and a considerably more negative oxidation potential. Furthermore, while the bisamidate complex (Ni(II)(L1))(2-) (2) readily forms a trinuclear species (Et(4)N)(2)({Ni(L1)}(2)Ni).H(2)O (1) and reacts rapidly with O(2), presumably via sulfoxidation, the mixed amine/amidate complex (Ni(II)(HL2))(-) (3) remains monomeric and is stable for days in air. Interestingly, the Ni(III) species of the bisamidate complex formed by chemical oxidation with I(2) can be detected by electron paramagnetic resonance (EPR) spectroscopy while the mixed amine/amidate complex immediately decomposes upon oxidation. To explain these experimentally observed properties, we performed S K-edge X-ray absorption spectroscopy and low-temperature (77 K) electronic absorption measurements as well as both hybrid density functional theory (hybrid-DFT) and spectroscopy oriented configuration interaction (SORCI) calculations. These studies demonstrate that the highest occupied molecular orbital (HOMO) of the bisamidate complex (Ni(II)(L1))(2-) (2) has more Ni character and is significantly destabilized relative to the mixed amine/amidate complex (Ni(II)(HL2))(-) (3) by approximately 6.2 kcal mol(-1). The consequence of this destabilization is manifested in the nucleophilic activation of the doubly filled HOMO, which makes (Ni(II)(L1))(2-) (2) significantly more reactive toward electrophiles such as O(2).
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Affiliation(s)
| | - Jason Thomas
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - Richard Staples
- Department of Chemistry, Michigan State University, East Lansing, MI 48824
| | - John McCraken
- Department of Chemistry, Michigan State University, East Lansing, MI 48824
| | - Jason Shearer
- Department of Chemistry, University of Nevada, Reno, NV 89557
| | - Eric L. Hegg
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824
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13
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Matsumoto T, Ito M, Kotera M, Tatsumi K. A dinuclear nickel complex modeling of the Nid(ii)-Nip(i) state of the active site of acetyl CoA synthase. Dalton Trans 2010; 39:2995-7. [DOI: 10.1039/b924915j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Jenkins RM, Singleton ML, Almaraz E, Reibenspies JH, Darensbourg MY. Imidazole-containing (N3S)-Ni(II) complexes relating to nickel containing biomolecules. Inorg Chem 2009; 48:7280-93. [PMID: 19572492 PMCID: PMC2908898 DOI: 10.1021/ic900778k] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dimeric (N(2)S)Ni complexes and the monomeric N(2)S(2) bismercaptodiazacycloheptane nickel complex, (bme-dach)Ni, serve as precursors to two N(2)-, N'-/ S- complexes where N(2) = diazacycloheptane, N' = imidazole and S = thiolate. As rare examples of nickel complexes containing a mixed thiolate/imidazole ligand set, these complexes are characterized by X-ray diffraction, UV/vis, and variable temperature (1)H NMR spectroscopies, and electrochemistry. Density functional theory computations relate the orientation of the imidazole with respect to the N(2)N'SNi square plane to the VT NMR observed fluxionality and activation parameters. The superoxide dismutase activity of the imidazole complexes was investigated by the nitroblue tetrazolium assay.
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Affiliation(s)
- Roxanne M. Jenkins
- Department of Chemistry, Texas A&M University, College Station, Texas 77843
| | | | - Elky Almaraz
- Department of Chemistry, Texas A&M University, College Station, Texas 77843
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15
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Dinuclear nickel complexes modeling the structure and function of the acetyl CoA synthase active site. Proc Natl Acad Sci U S A 2009; 106:11862-6. [PMID: 19584250 DOI: 10.1073/pnas.0900433106] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A dinuclear nickel complex with methyl and thiolate ligands, Ni(dadt(Et))Ni(Me)(SDmp) (2), has been synthesized as a dinuclear Ni(d)-Ni(p)-site model of acetyl-CoA synthase (ACS) (dadt(Et) is N,N'-diethyl-3,7-diazanonane-1,9-dithiolate; Dmp is 2,6-dimesitylphenyl). Complex 2 was prepared via 2 methods: (i) ligand substitution of a dinuclear Ni(II)-Ni(II) cation complex [Ni(dadt(Et)) Ni(tmtu)2] (OTf)2 (1) with MeMgBr and KSDmp (tmtu is tetramethylthiourea), (ii) methyl transfer from methylcobaloxime Co(dmgBF2)2(Me)(Py) (5) to a Ni(II)-Ni(0) complex such as [Ni(dadt(Et))Ni(cod)] (3), generated in situ from Ni(dadt(Et)) and Ni(cod)(2), followed by addition of KSDmp (cod is 1,5-cyclooctadiene; dmgBF2 is difluoroboryl-dimethylglyoximate). Method ii models the formation of Nip-Me species proposed as a plausible intermediate in ACS catalysis. The reaction of 2 with excess CO affords the acetylthioester CH3C(O)SDmp (8) with concomitant formation of Ni(dadt(Et))Ni(CO)2 (9) and Ni(CO)4 plus Ni(dadt(Et)). When complex 2 is treated with 1 equiv of CO in the presence of excess 1,5-cyclooctadiene, the formation of 9 and Ni(CO)4 is considerably suppressed, and instead the dinuclear Ni(II)-Ni(0) complex is generated in situ, which further affords 2 upon successive treatment with Co(dmgBF2)2(Me)(Py) (5) and KSDmp. These results suggest that (i) ACS catalysis could include the Nid(II)-Nip(0) state as the active species, (ii) The Nid(II)-Nip(0) species could first react with methylcobalamin to afford Nid(II)-Nip(II)-Me, and (iii) CO insertion into the Nip-Me bond and the successive reductive elimination of acetyl-CoA occurs immediately when CoA is coordinated to the Nip site to form the active Nid(II)-Nip(0) species.
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16
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Ariyananda PWG, Kieber-Emmons MT, Yap GPA, Riordan CG. Synthetic analogs for evaluating the influence of N-H...S hydrogen bonds on the formation of thioester in acetyl coenzyme A synthase. Dalton Trans 2009:4359-69. [PMID: 19662314 DOI: 10.1039/b901192g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of square planar methylnickel(II) complexes, (dppe)Ni(Me)(SAr) (dppe = 1,2-bis(diphenylphosphino)ethane); 2. Ar = phenyl; 3. Ar = pentafluorophenyl; 4. Ar = o-pivaloylaminophenyl; 5. Ar = p-pivaloylaminophenyl; (depe)Ni(Me)(SAr), (depe = 1,2-bis(diethylphosphino)ethane); 7. Ar = phenyl; 8. Ar = pentafluorophenyl; 9. Ar = o-pivaloylaminophenyl; 10. Ar = p-pivaloylaminophenyl), were synthesized via the reaction of (dppe)NiMe(2) (1) and (depe)NiMe(2) (6) with either the corresponding thiol or disulfide. These complexes were characterized by various spectroscopic methods including (31)P NMR, (1)H NMR, (13)C NMR and infrared spectroscopies and in most cases by X-ray diffraction analyses. Solid state and solution measurements establish that 4 and 9 contain intramolecular N-H...S bonds. Carbonylation of the complexes 2-4, 7-10 leads to (dRpe)Ni(CO)(2) and MeC(O)SAr via the intermediacy of the acylnickel adducts, (dRpe)Ni(C(O)Me)(SAr), detected at low temperature by (31)P NMR spectroscopy. Consistent with experimental observations, density functional theory results reveal that the intramolecular hydrogen bond in 9 stabilizes the acylnickel adduct compared with its non-hydrogen-bonded adduct, 10. Oxidative addition of MeC(O)SC(6)F(5) to (dRpe)Ni(COD) followed by spontaneous decarbonylation proceeds in variable yields generating 3 and 8.
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Affiliation(s)
- Piyal W G Ariyananda
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
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Ito M, Kotera M, Song Y, Matsumoto T, Tatsumi K. Structural models for the active site of acetyl-CoA synthase: synthesis of dinuclear nickel complexes having thiolate, isocyanide, and thiourea on the Ni(p) site. Inorg Chem 2009; 48:1250-6. [PMID: 19128153 DOI: 10.1021/ic801967e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The trinuclear nickel complex [{Ni(dadt(Et))}(2)Ni](NiBr(4)) (dadt(Et) = N,N'-diethyl-3,7-diazanonane-1,9-dithiolate) (1a), prepared by the reaction of Ni(dadt(Et)) and Ni(EtOH)(4)Br(2), was found to serve as a useful synthetic precursor of various dinuclear nickel complexes modeling the active site of acetyl-CoA synthase (ACS). The reactions of 1a with 4 equiv of the potassium salts of arenethiolates in ethanol produced a series of dinuclear nickel thiolate complexes Ni(dadt(Et))Ni(SAr)(2) (Ar = Ph (2a), p-Tol (2b), 2,4,6-triisopropylphenyl (Tip) (2c)) in good yields. The analogous reactions of 1a with Ag(OTf) in the presence of (t)BuNC and (NMe(2))(2)CS (tmtu) generated the dicationic dinuclear nickel complexes [Ni(dadt(Et))Ni((t)BuNC)(2)](OTf)(2) (3) and [Ni(dadt(Et))Ni(tmtu)(2)](OTf)(2) (4), respectively. The molecular structures of 1a, 2a-c, 3, and 4 determined by X-ray analysis compare well with that of A-cluster in ACS.
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Affiliation(s)
- Mikinao Ito
- Research Center for Materials Science, and Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Song Y, Ito M, Kotera M, Matsumoto T, Tatsumi K. Cationic and Anionic Dinuclear Nickel Complexes [Ni(N2S2)Ni(dtc)]n(n=−1, +1) Modeling the Active Site of Acetyl-CoA Synthase. CHEM LETT 2009. [DOI: 10.1246/cl.2009.184] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Dougherty WG, Rangan K, O'Hagan MJ, Yap GPA, Riordan CG. Binuclear complexes containing a methylnickel moiety: relevance to organonickel intermediates in acetyl coenzyme A synthase catalysis. J Am Chem Soc 2008; 130:13510-1. [PMID: 18800791 DOI: 10.1021/ja803795k] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of binuclear NiNi complexes supported by a single thiolate bridge and containing a methylnickel moiety have been prepared and fully characterized. The complexes represent structural analogues for the proposed organonickel intermediate in the acetyl coenzyme A synthase catalytic cycle. Variable temperature 31P NMR spectroscopy was used to examine dynamic behavior of the thiolate bridging interaction in two of the derivatives. Kinetic analyses, independent exchange and crossover experiments support an intermolecular exchange mechanism. Carbonylation results in thioester formation via a reductive elimination pathway.
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Affiliation(s)
- William G Dougherty
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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Sharma SK, Upreti S, Gupta R. Effect of Ligand Architecture on the Structure and Properties of Square-Planar Nickel(II) Complexes of Amide-Based Macrocycles. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700122] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Redin K, Wilson AD, Newell R, DuBois MR, DuBois DL. Studies of Structural Effects on the Half-Wave Potentials of Mononuclear and Dinuclear Nickel(II) Diphosphine/Dithiolate Complexes. Inorg Chem 2007; 46:1268-76. [PMID: 17249658 DOI: 10.1021/ic061740x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two series of mononuclear Ni(II) complexes of the formula (PNP)Ni(dithiolate) where PNP = R2PCH2N(CH3)CH2PR2, R = Et and Ph, have been synthesized containing dithiolate ligands that vary from five- to seven-membered chelate rings. Two series of dinuclear Ni(II) complexes of the formula {[(diphosphine)Ni]2(dithiolate)}(X)2 (X = BF4 or PF6) have been synthesized in which the chelate ring size of the dithiolate and diphosphine ligands have been systematically varied. The structures of the alkylated mononuclear complex, [(PNPEt)Ni(SC2H4SMe)]OTf, and the dinuclear complex, [(dppeNi)2(SC3H6S)](BF4)2, have been determined by X-ray diffraction studies. The complexes have been studied by cyclic voltammetry to determine how the half-wave potentials of the Ni(II/I) couples vary with chelate ring size of the ligands. For the mononuclear complexes, this potential becomes more positive as the natural bite angle of the dithiolate ligand increases. However, the potentials of the Ni(II/I) couples of the dinuclear complexes do not show a dependence on the chelate ring size of the ligands. Other aspects of the reduction chemistry of these complexes have been explored.
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Affiliation(s)
- Kendra Redin
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA
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Verhagen JAW, Tock C, Lutz M, Spek AL, Bouwman E. Nickel Thiolate Complexes as Ligands for Copper and Zinc: Novel Additions to a Library of Binding Modes. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600645] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Harrop TC, Mascharak PK. Structural and spectroscopic models of the A-cluster of acetyl coenzyme a synthase/carbon monoxide dehydrogenase: Nature's Monsanto acetic acid catalyst. Coord Chem Rev 2005. [DOI: 10.1016/j.ccr.2005.04.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Duff SE, Elaine Barclay J, Davies SC, Hitchcock PB, Evans DJ. Synthesis and Structural Characterisation of Group 10 Homo- and Hetero-Dimetallic Sulfur-Bridged Complexes of the [Ni(ema)(μ-S,S′)M(diphos)](M = Ni, Pd, Pt) Type. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500678] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Homonuclear dinickel complexes: structural mimics for the dinickel subsite of the A-cluster of acetyl-CoA synthase. INORG CHEM COMMUN 2005. [DOI: 10.1016/j.inoche.2004.11.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Lindahl PA. Acetyl-coenzyme A synthase: the case for a Nip0-based mechanism of catalysis. J Biol Inorg Chem 2004; 9:516-24. [PMID: 15221478 DOI: 10.1007/s00775-004-0564-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 05/21/2004] [Indexed: 11/30/2022]
Abstract
Acetyl-CoA synthase (also known as carbon monoxide dehydrogenase) is a bifunctional Ni-Fe-S-containing enzyme that catalyzes the reversible reduction of CO(2) to CO and the synthesis of acetyl-coenzyme A from CO, CoA, and a methyl group donated by a corrinoid iron-sulfur protein. The active site for the latter reaction, called the A-cluster, consists of an Fe(4)S(4) cubane bridged to the proximal Ni site (Ni(p)), which is bridged in turn to the so-called distal Ni site. In this review, evidence is presented that Ni(p) achieves a zero-valent state at low potentials and during catalysis. Ni(p) appears to be the metal to which CO and methyl groups bind and then react to form an acetyl-Ni(p) intermediate. Methyl group binding requires reductive activation, where two electrons reduce some site on the A-cluster. The coordination environment of the distal Ni suggests that it could not be stabilized in redox states lower than 2+. The rate at which the [Fe(4)S(4)](2+) cubane is reduced is far slower than that at which reductive activation occurs, suggesting that the cubane is not the site of reduction. An intriguing possibility is that Ni(p)(2+) might be reduced to the zero-valent state. Reinforcing this idea are Ni-organometallic complexes in which the Ni exhibits analogous reactivity properties when reduced to the zero-valent state. A zero-valent Ni stabilized exclusively with biological ligands would be remarkable and unprecedented in biology.
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Affiliation(s)
- Paul A Lindahl
- Departments of Chemistry and of Biochemistry and Biophysics, Texas A and M University, College Station, TX 77843-3255, USA.
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Riordan CG. Synthetic chemistry and chemical precedents for understanding the structure and function of acetyl coenzyme A synthase. J Biol Inorg Chem 2004; 9:542-9. [PMID: 15221481 DOI: 10.1007/s00775-004-0567-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Accepted: 05/21/2004] [Indexed: 10/26/2022]
Abstract
Acetyl coenzyme A synthase (ACS), found in acetogenic and methanogenic organisms, is responsible for the synthesis and breakdown of acetate. The mechanism by which methylcob(III)alamin, CO and coenzyme A are assembled/disassembled at the active-site A-cluster involves a number of biologically unprecedented intermediates. In the past two years, two protein crystal structures have significantly enhanced the understanding of the structure of the active-site A-cluster, responsible for catalysis. The structure reports spawned a number of important questions regarding the metal ion constitution of the active enzyme, the structure(s) of the spectroscopically identified states and the details of the catalytic mechanism. This Commentary addresses these issues in the framework of existing synthetic and chemical precedent studies aimed at developing rational structure-function correlations and presents structural and reactivity targets for future studies.
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Affiliation(s)
- Charles G Riordan
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
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