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Gera R, De P, Singh KK, Jannuzzi SAV, Mohanty A, Velasco L, Kulbir, Kumar P, Marco JF, Nagarajan K, Pecharromán C, Rodríguez-Pascual PM, DeBeer S, Moonshiram D, Gupta SS, Dasgupta J. Trapping an Elusive Fe(IV)-Superoxo Intermediate Inside a Self-Assembled Nanocage in Water at Room Temperature. J Am Chem Soc 2024; 146:21729-21741. [PMID: 39078020 DOI: 10.1021/jacs.4c05849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Molecular cavities that mimic natural metalloenzymes have shown the potential to trap elusive reaction intermediates. Here, we demonstrate the formation of a rare yet stable Fe(IV)-superoxo intermediate at room temperature subsequent to dioxygen binding at the Fe(III) site of a (Et4N)2[FeIII(Cl)(bTAML)] complex confined inside the hydrophobic interior of a water-soluble Pd6L412+ nanocage. Using a combination of electron paramagnetic resonance, Mössbauer, Raman/IR vibrational, X-ray absorption, and emission spectroscopies, we demonstrate that the cage-encapsulated complex has a Fe(IV) oxidation state characterized by a stable S = 1/2 spin state and a short Fe-O bond distance of ∼1.70 Å. We find that the O2 reaction in confinement is reversible, while the formed Fe(IV)-superoxo complex readily reacts when presented with substrates having weak C-H bonds, highlighting the lability of the O-O bond. We envision that such optimally trapped high-valent superoxos can show new classes of reactivities catalyzing both oxygen atom transfer and C-H bond activation reactions.
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Affiliation(s)
- Rahul Gera
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
- Department of Education in Science and Mathematics, Regional Institute of Education - Mysuru, NCERT, Mysuru 570006, India
| | - Puja De
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Kundan K Singh
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Pune, Maharashtra 411008, India
- Chemistry Department, Indian Institute of Technology, Dharwad 580007, India
| | - Sergio A V Jannuzzi
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, Mülheim an der Ruhr 45470, Germany
| | - Aisworika Mohanty
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Lucia Velasco
- Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas Sor Juana Inés de la Cruz, 3, Madrid 28049, Spain
| | - Kulbir
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Tirupati 517507, India
| | - Pankaj Kumar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Tirupati 517507, India
| | - J F Marco
- Instituto de Quimica Fisica Blas Cabrera, Consejo Superior de Investigaciones Científicas, Serrano 119, Madrid 28006, Spain
| | - Kalaivanan Nagarajan
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Carlos Pecharromán
- Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas Sor Juana Inés de la Cruz, 3, Madrid 28049, Spain
| | - P M Rodríguez-Pascual
- Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas Sor Juana Inés de la Cruz, 3, Madrid 28049, Spain
| | - Serena DeBeer
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, Mülheim an der Ruhr 45470, Germany
| | - Dooshaye Moonshiram
- Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas Sor Juana Inés de la Cruz, 3, Madrid 28049, Spain
| | - Sayam Sen Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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2
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Xu S, Zhao J, Liu X, Yang X, Xu Z, Gao Y, Ma Y, Yang H. Structures of SenB and SenA enzymes from Variovorax paradoxus provide insights into carbon-selenium bond formation in selenoneine biosynthesis. Heliyon 2024; 10:e32888. [PMID: 38994077 PMCID: PMC11237966 DOI: 10.1016/j.heliyon.2024.e32888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 07/13/2024] Open
Abstract
Selenoneine, an ergothioneine analog, is important for antioxidation and detoxification. SenB and SenA are two crucial enzymes that form carbon-selenium bonds in the selenoneine biosynthetic pathway. To investigate their underlying catalytic mechanisms, we obtained complex structures of SenB with its substrate UDP-N-acetylglucosamine (UDP-GlcNAc) and SenA with N-α-trimethyl histidine (TMH). SenB adopts a type-B glycosyltransferase fold. Structural and functional analysis of the interaction network at the active center provide key information on substrate recognition and suggest a metal-ion-independent, inverting mechanism is utilized for SenB-mediated selenoglycoside formation. Moreover, the complex structure of SenA with TMH and enzymatic activity assays highlight vital residues that control substrate binding and specificity. Based on the conserved structure and substrate-binding pocket of the type I sulfoxide synthase EgtB in the ergothioneine biosynthetic pathway, a similar reaction mechanism was proposed for the formation of C-Se bonds by SenA. The structures provide knowledge on selenoneine synthesis and lay groundwork for further applications of this pathway.
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Affiliation(s)
- Sihan Xu
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jinyi Zhao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiang Liu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Response, College of Life Sciences, College of Pharmacy, Nankai University, Tianjin, China
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zili Xu
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yuanyuan Ma
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
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3
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Chatterjee S, Paine TK. Dioxygen Reduction and Bioinspired Oxidations by Non-heme Iron(II)-α-Hydroxy Acid Complexes. Acc Chem Res 2023; 56:3175-3187. [PMID: 37938969 DOI: 10.1021/acs.accounts.3c00449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Aerobic organisms involve dioxygen-activating iron enzymes to perform various metabolically relevant chemical transformations. Among these enzymes, mononuclear non-heme iron enzymes reductively activate dioxygen to catalyze diverse biological oxidations, including oxygenation of C-H and C═C bonds and C-C bond cleavage with amazing selectivity. Several non-heme enzymes utilize organic cofactors as electron sources for dioxygen reduction, leading to the generation of iron-oxygen intermediates that act as active oxidants in the catalytic cycle. These unique enzymatic reactions influence the design of small molecule synthetic compounds to emulate enzyme functions and to develop bioinspired catalysts for performing selective oxidation of organic substrates with dioxygen. Selective electron transfer during dioxygen reduction on iron centers of synthetic models by a sacrificial reductant requires appropriate design strategies. Taking lessons from the role of enzyme-cofactor complexes in the selective electron transfer process, our group utilized ternary iron(II)-α-hydroxy acid complexes supported by polydentate ligands for dioxygen reduction and bioinspired oxidations. This Account focuses on the role of coordinated sacrificial reductants in the selective electron transfer for dioxygen reduction by iron complexes and highlights the versatility of iron(II)-α-hydroxy acid complexes in affecting dioxygen-dependent oxidation/oxygenation reactions. The iron(II)-coordinated α-hydroxy acid anions undergo two-electron oxidative decarboxylation concomitant with the generation of reactive iron-oxygen oxidants. A nucleophilic iron(II)-hydroperoxo species was intercepted in the decarboxylation pathway. In the presence of a Lewis acid, the O-O bond of the nucleophilic oxidant is heterolytically cleaved to generate an electrophilic iron(IV)-oxo-hydroxo oxidant. Most importantly, the oxidants generated with or without Lewis acid can carry out cis-dihydroxylation of alkenes. Furthermore, the electrophilic iron-oxygen oxidant selectively hydroxylates strong C-H bonds. Another electrophilic iron(IV)-oxo oxidant, generated from the iron(II)-α-hydroxy acid complexes in the presence of a protic acid, carries out C-H bond halogenation by using a halide anion.Thus, different metal-oxygen intermediates could be generated from dioxygen using a single reductant, and the reactivity of the ternary complexes can be tuned using external additives (Lewis/protic acid). The catalytic potential of the iron(II)-α-hydroxy complexes in performing O2-dependent oxygenations has been demonstrated. Different factors that govern the reactivity of iron-oxygen oxidants from ternary iron(II) complexes are presented. The versatile reactivity of the oxidants provides useful insights into developing catalytic methods for the selective incorporation of oxidized functionalities under environmentally benign conditions using aerial oxygen as the terminal oxidant.
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Affiliation(s)
- Sayanti Chatterjee
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A&2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Tapan Kanti Paine
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A&2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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4
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Monika, Ansari A. Electronic structures and energetic of metal(II)-superoxo species: a DFT exploration. Struct Chem 2022. [DOI: 10.1007/s11224-022-02030-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Csizi KS, Eckert L, Brunken C, Hofstetter TB, Reiher M. The Apparently Unreactive Substrate Facilitates the Electron Transfer for Dioxygen Activation in Rieske Dioxygenases. Chemistry 2022; 28:e202103937. [PMID: 35072969 PMCID: PMC9306888 DOI: 10.1002/chem.202103937] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Indexed: 12/29/2022]
Abstract
Rieske dioxygenases belong to the non‐heme iron family of oxygenases and catalyze important cis‐dihydroxylation as well as O‐/N‐dealkylation and oxidative cyclization reactions for a wide range of substrates. The lack of substrate coordination at the non‐heme ferrous iron center, however, makes it particularly challenging to delineate the role of the substrate for productive O2
activation. Here, we studied the role of the substrate in the key elementary reaction leading to O2
activation from a theoretical perspective by systematically considering (i) the 6‐coordinate to 5‐coordinate conversion of the non‐heme FeII upon abstraction of a water ligand, (ii) binding of O2
, and (iii) transfer of an electron from the Rieske cluster. We systematically evaluated the spin‐state‐dependent reaction energies and structural effects at the active site for all combinations of the three elementary processes in the presence and absence of substrate using naphthalene dioxygenase as a prototypical Rieske dioxygenase. We find that reaction energies for the generation of a coordination vacancy at the non‐heme FeII
center through thermoneutral H2O reorientation and exothermic O2
binding prior to Rieske cluster oxidation are largely insensitive to the presence of naphthalene and do not lead to formation of any of the known reactive Fe‐oxygen species. By contrast, the role of the substrate becomes evident after Rieske cluster oxidation and exclusively for the 6‐coordinate non‐heme FeII
sites in that the additional electron is found at the substrate instead of at the iron and oxygen atoms. Our results imply an allosteric control of the substrate on Rieske dioxygenase reactivity to happen prior to changes at the non‐heme FeII
in agreement with a strategy that avoids unproductive O2
activation.
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Affiliation(s)
- Katja-Sophia Csizi
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland.,ETH Zürich, Laboratory for Physical Chemistry, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Lina Eckert
- ETH Zürich, Laboratory for Physical Chemistry, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Christoph Brunken
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland.,ETH Zürich, Laboratory for Physical Chemistry, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland
| | - Markus Reiher
- ETH Zürich, Laboratory for Physical Chemistry, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
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6
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Wu L, Wang Z, Cen Y, Wang B, Zhou J. Structural Insight into the Catalytic Mechanism of the Endoperoxide Synthase FtmOx1. Angew Chem Int Ed Engl 2022; 61:e202112063. [PMID: 34796596 DOI: 10.1002/anie.202112063] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Indexed: 11/11/2022]
Abstract
The 2-oxoglutarate (2OG)-dependent non-heme enzyme FtmOx1 catalyzes the endoperoxide biosynthesis of verruculogen. Although several mechanistic studies have been carried out, the catalytic mechanism of FtmOx1 is not well determined owing to the lack of a reliable complex structure of FtmOx1 with fumitremorgin B. Herein we provide the X-ray crystal structure of the ternary complex FtmOx1⋅2OG⋅fumitremorgin B at a resolution of 1.22 Å. Our structures show that the binding of fumitremorgin B induces significant compression of the active pocket and that Y68 is in close proximity to C26 of the substrate. Further MD simulation and QM/MM calculations support a CarC-like mechanism, in which Y68 acts as the H atom donor for quenching the C26-centered substrate radical. Our results are consistent with all available experimental data and highlight the importance of accurate complex structures in the mechanistic study of enzymatic catalysis.
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Affiliation(s)
- Lian Wu
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, University of Chinese Academy of Sciences, Shanghai, 200032, China
| | - Zhanfeng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yixin Cen
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, University of Chinese Academy of Sciences, Shanghai, 200032, China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jiahai Zhou
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
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7
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Wu L, Wang Z, Cen Y, Wang B, Zhou J. Structural Insight into the Catalytic Mechanism of the Endoperoxide Synthase FtmOx1. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202112063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Lian Wu
- The Research Center of Chiral Drugs Innovation Research Institute of Traditional Chinese Medicine (IRI) Shanghai University of Traditional Chinese Medicine Shanghai 201203 China
- Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant Sciences University of Chinese Academy of Sciences Shanghai 200032 China
| | - Zhanfeng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Yixin Cen
- The Research Center of Chiral Drugs Innovation Research Institute of Traditional Chinese Medicine (IRI) Shanghai University of Traditional Chinese Medicine Shanghai 201203 China
- Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant Sciences University of Chinese Academy of Sciences Shanghai 200032 China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Jiahai Zhou
- CAS Key Laboratory of Quantitative Engineering Biology Shenzhen Institute of Synthetic Biology Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China
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8
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Sacramento JJD, Albert T, Siegler M, Moënne-Loccoz P, Goldberg DP. An Iron(III) Superoxide Corrole from Iron(II) and Dioxygen. Angew Chem Int Ed Engl 2022; 61:e202111492. [PMID: 34850509 PMCID: PMC8789326 DOI: 10.1002/anie.202111492] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/20/2021] [Indexed: 01/12/2023]
Abstract
A new structurally characterized ferrous corrole [FeII (ttppc)]- (1) binds one equivalent of dioxygen to form [FeIII (O2-. )(ttppc)]- (2). This complex exhibits a 16/18 O2 -isotope sensitive ν(O-O) stretch at 1128 cm-1 concomitantly with a single ν(Fe-O2 ) at 555 cm-1 , indicating it is an η1 -superoxo ("end-on") iron(III) complex. Complex 2 is the first well characterized Fe-O2 corrole, and mediates the following biologically relevant oxidation reactions: dioxygenation of an indole derivative, and H-atom abstraction from an activated O-H bond.
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Affiliation(s)
- Jireh Joy D Sacramento
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, 97239-3098, USA
| | - Maxime Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, 97239-3098, USA
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
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9
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Sacramento JJD, Albert T, Siegler M, Moënne‐Loccoz P, Goldberg DP. An Iron(III) Superoxide Corrole from Iron(II) and Dioxygen. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202111492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jireh Joy D. Sacramento
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry Oregon Health & Science University Portland OR 97239-3098 USA
| | - Maxime Siegler
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
| | - Pierre Moënne‐Loccoz
- Department of Chemical Physiology and Biochemistry Oregon Health & Science University Portland OR 97239-3098 USA
| | - David P. Goldberg
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
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10
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Dubourdeaux P, Blondin G, Latour JM. Mixed Valence (μ-Phenoxido) Fe II Fe III et Fe III Fe IV Compounds: Electron and Proton Transfers. Chemphyschem 2021; 23:e202100399. [PMID: 34633731 DOI: 10.1002/cphc.202100399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/03/2021] [Indexed: 11/08/2022]
Abstract
Mixed-valence non-heme diiron centers are present at the active sites of a few enzymes and confer them interesting reactivities with the two ions acting in concert. Related (μ-phenoxido)diiron complexes have been developed as enzyme mimics. They exhibit very rich spectroscopic properties enabling independent monitoring of each individual ion, which proved useful for mechanistic studies of catalytic hydrolysis and oxidation reactions. In our studies of such complexes, we observed that these compounds give rise to a wide variety of electron transfers (intervalence charge transfer), proton transfers (tautomerism), coupled electron and proton transfers (H. abstraction and PCET). In this minireview, we present and analyze the main results illustrating the latter aspects.
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Affiliation(s)
| | - Geneviève Blondin
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-LCBM/pmb, F-38000, Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-LCBM/pmb, F-38000, Grenoble, France
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11
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Zhu W, Jang S, Xiong J, Ezhov R, Li XX, Kim T, Seo MS, Lee YM, Pushkar Y, Sarangi R, Guo Y, Nam W. A Mononuclear Non-heme Iron(III)-Peroxo Complex with an Unprecedented High O-O Stretch and Electrophilic Reactivity. J Am Chem Soc 2021; 143:15556-15561. [PMID: 34529428 DOI: 10.1021/jacs.1c03358] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A mononuclear non-heme iron(III)-peroxo complex, [Fe(III)(O2)(13-TMC)]+ (1), was synthesized and characterized spectroscopically; the characterization with electron paramagnetic resonance, Mössbauer, X-ray absorption, and resonance Raman spectroscopies and mass spectrometry supported a high-spin S = 5/2 Fe(III) species binding an O2 unit. A notable observation was an unusually high νO-O at ∼1000 cm-1 for the peroxo ligand. With regard to reactivity, 1 showed electrophilic reactivity in H atom abstraction (HAA) and O atom transfer (OAT) reactions. In the HAT reaction, a kinetic isotope effect (KIE) value of 5.8 was obtained in the oxidation of 9,10-dihydroanthracene. In the OAT reaction, a negative ρ value of -0.61 in the Hammett plot was determined in the oxidation of p-X-substituted thioanisoles. Another interesting observation was the electrophilic reactivity of 1 in the oxidation of benzaldehyde derivatives, such as a negative ρ value of -0.77 in the Hammett plot and a KIE value of 2.2. To the best of our knowledge, the present study reports the first example of a mononuclear non-heme iron(III)-peroxo complex with an unusually high νO-O value and unprecedented electrophilic reactivity in oxidation reactions.
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Affiliation(s)
- Wenjuan Zhu
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Semin Jang
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Jin Xiong
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Roman Ezhov
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Taeyeon Kim
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yulia Pushkar
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford, California 94025, United States
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.,School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
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12
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Banerjee A, Li J, Molenda MA, Opalade AA, Adhikary A, Brennessel WW, Malkhasian AYS, Jackson TA, Chavez FA. Probing the Mechanism for 2,4'-Dihydroxyacetophenone Dioxygenase Using Biomimetic Iron Complexes. Inorg Chem 2021; 60:7168-7179. [PMID: 33900072 DOI: 10.1021/acs.inorgchem.1c00167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we report the synthesis and characterization of [Fe(T1Et4iPrIP)(2-OH-AP)(OTf)](OTf) (2), [Fe(T1Et4iPrIP)(2-O-AP)](OTf) (3), and [Fe(T1Et4iPrIP)(DMF)3](OTf)3 (4) (T1Et4iPrIP = tris(1-ethyl-4-isopropyl-imidazolyl)phosphine; 2-OH-AP = 2-hydroxyacetophenone, and 2-O-AP- = monodeprotonated 2-hydroxyacetophenone). Both 2 and 3 serve as model complexes for the enzyme-substrate adduct for the nonheme enzyme 2,4'-dihydroacetophenone (DHAP) dioxygenase or DAD, while 4 serves as a model for the ferric form of DAD. Complexes 2-4 have been characterized by X-ray crystallography which reveals T1Et4iPrIP to bind iron in a tridentate fashion. Complex 2 additionally contains a bidentate 2-OH-AP ligand and a monodentate triflate ligand yielding distorted octahedral geometry, while 3 possesses a bidentate 2-O-AP- ligand and exhibits distorted trigonal bipyramidal geometry (τ = 0.56). Complex 4 displays distorted octahedral geometry with 3 DMF ligands completing the ligand set. The UV-vis spectrum of 2 matches more closely to the DAD-substrate spectrum than 3, and therefore, it is believed that the substrate for DAD is bound in the protonated form. TD-DFT studies indicate that visible absorption bands for 2 and 3 are due to MLCT bands. Complexes 2 and 3 are capable of oxidizing the coordinated substrate mimics in a stoichiometric and catalytic fashion in the presence of O2. Complex 4 does not convert 2-OH-AP to products under the same catalytic conditions; however, it becomes anaerobically reduced in the presence of 2 equiv 2-OH-AP to 2.
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Affiliation(s)
- Atanu Banerjee
- Dr. K. C. Patel R & D Centre, Charotar University of Science and Technology (CHARUSAT), P D Patel Institute of Applied Sciences, 388421 Anand, Gujrat, India
| | - Jia Li
- Department of Chemistry, Oakland University, Rochester, Michigan 48309-4477, United States
| | - Monika A Molenda
- Department of Chemistry, Oakland University, Rochester, Michigan 48309-4477, United States
| | - Adedamola A Opalade
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, Rochester, Michigan 48309-4477, United States
| | - William W Brennessel
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
| | | | - Timothy A Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Ferman A Chavez
- Department of Chemistry, Oakland University, Rochester, Michigan 48309-4477, United States
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13
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The catalytic mechanism of sulfoxide synthases. Curr Opin Chem Biol 2020; 59:111-118. [PMID: 32726707 DOI: 10.1016/j.cbpa.2020.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/09/2020] [Accepted: 06/17/2020] [Indexed: 02/06/2023]
Abstract
Sulfoxide synthases are non-heme iron enzymes that catalyze oxidative carbonsulfur bond formation in the biosynthesis of thiohistidines such as ergothioneine and ovothiol. The catalytic mechanism of these enzymes has been studied by protein crystallography, steady-state kinetics, non-natural amino acid incorporation and computational modeling. This review discusses the current status of this research and also highlights similarities between the CS bond forming activity of sulfoxide synthases with that of synthetic coordination compounds.
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14
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Yee DA, Kakule TB, Cheng W, Chen M, Chong CTY, Hai Y, Hang LF, Hung YS, Liu N, Ohashi M, Okorafor IC, Song Y, Tang M, Zhang Z, Tang Y. Genome Mining of Alkaloidal Terpenoids from a Hybrid Terpene and Nonribosomal Peptide Biosynthetic Pathway. J Am Chem Soc 2020; 142:710-714. [PMID: 31885262 DOI: 10.1021/jacs.9b13046] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Biosynthetic pathways containing multiple core enzymes have potential to produce structurally complex natural products. Here we mined a fungal gene cluster that contains two predicted terpene cyclases (TCs) and a nonribosomal peptide synthetase (NRPS). We showed the flv pathway produces flavunoidine 1, an alkaloidal terpenoid. The core of 1 is a tetracyclic, cage-like, and oxygenated sesquiterpene that is connected to dimethylcadaverine via a C-N bond and is acylated with 5,5-dimethyl-l-pipecolate. The roles of all flv enzymes are established on the basis of metabolite analysis from heterologous expression.
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Affiliation(s)
| | | | - Wei Cheng
- State Key Laboratory of Natural and Biomimetic Drugs , Peking University , Beijing 100191 , China
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15
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Alkane and alkene oxidation reactions catalyzed by nickel(II) complexes: Effect of ligand factors. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213085] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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16
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Devi T, Lee YM, Nam W, Fukuzumi S. Tuning Electron-Transfer Reactivity of a Chromium(III)–Superoxo Complex Enabled by Calcium Ion and Other Redox-Inactive Metal Ions. J Am Chem Soc 2019; 142:365-372. [DOI: 10.1021/jacs.9b11014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Tarali Devi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
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17
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Zhang S, Liu Y. Mechanism of fatty acid decarboxylation catalyzed by a non-heme iron oxidase (UndA): a QM/MM study. Org Biomol Chem 2019; 17:9808-9818. [PMID: 31710061 DOI: 10.1039/c9ob02116g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UndA is a non-heme iron enzyme that was recognized to catalyze the decarboxylation of medium chain (C10-C14) fatty acids to produce trace amounts of 1-alkenes. Owing to the electron imbalance during the oxidative decarboxylation of the substrate and the reduction of O2, only single turnover reactions were obtained in UndA in vitro assays. Unlike the general non-heme iron enzymes, the catalytic efficiency of UndA is quite low. According to the previous proposal, both FeIII-OO˙- and FeIV[double bond, length as m-dash]O complexes may abstract the β-H of fatty acids to trigger the oxidative decarboxylation reaction. Herein, on the basis of the crystal structures of UndA in complex with the substrate analogues, we constructed a series of computational models and performed quantum mechanics/molecular mechanics (QM/MM) calculations to explore the UndA-catalyzed decarboxylation using lauric acid as the substrate. Our calculation results reveal that only the FeIII-OO˙- complex can initiate the decarboxylation, and the substrate (lauric acid) should monodentately coordinate to the Fe center to facilitate the β-H abstraction. In addition, the monodentate coordination corresponds to higher relative energy than the bidentate mode, which may explain the low efficiency of UndA. It is also revealed that as long as the β-H is extracted by the FeIII-OO˙-, the decarboxylation of the substrate radical is quite easy, and an electron transfer from the substrate to the iron center is the prerequisite. For the FeIV[double bond, length as m-dash]O complex, since the β-H is far from the OFe atom and the angle of ∠Fe-O-H is 53.1°, the H-abstraction is calculated to be difficult.
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Affiliation(s)
- Shiqing Zhang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China.
| | - Yongjun Liu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China.
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18
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Zhang B, Rajakovich LJ, Van Cura D, Blaesi EJ, Mitchell AJ, Tysoe CR, Zhu X, Streit BR, Rui Z, Zhang W, Boal AK, Krebs C, Bollinger JM. Substrate-Triggered Formation of a Peroxo-Fe 2(III/III) Intermediate during Fatty Acid Decarboxylation by UndA. J Am Chem Soc 2019; 141:14510-14514. [PMID: 31487162 DOI: 10.1021/jacs.9b06093] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The iron-dependent oxidase UndA cleaves one C3-H bond and the C1-C2 bond of dodecanoic acid to produce 1-undecene and CO2. A published X-ray crystal structure showed that UndA has a heme-oxygenase-like fold, thus associating it with a structural superfamily that includes known and postulated non-heme diiron proteins, but revealed only a single iron ion in the active site. Mechanisms proposed for initiation of decarboxylation by cleavage of the C3-H bond using a monoiron cofactor to activate O2 necessarily invoked unusual or potentially unfeasible steps. Here we present spectroscopic, crystallographic, and biochemical evidence that the cofactor of Pseudomonas fluorescens Pf-5 UndA is actually a diiron cluster and show that binding of the substrate triggers rapid addition of O2 to the Fe2(II/II) cofactor to produce a transient peroxo-Fe2(III/III) intermediate. The observations of a diiron cofactor and substrate-triggered formation of a peroxo-Fe2(III/III) intermediate suggest a small set of possible mechanisms for O2, C3-H and C1-C2 activation by UndA; these routes obviate the problematic steps of the earlier hypotheses that invoked a single iron.
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Affiliation(s)
| | | | | | | | | | | | - Xuejun Zhu
- Department of Chemical and Biomolecular Engineering , University of California Berkeley , Berkeley , California 94720 , United States
| | | | - Zhe Rui
- Department of Chemical and Biomolecular Engineering , University of California Berkeley , Berkeley , California 94720 , United States
| | - Wenjun Zhang
- Department of Chemical and Biomolecular Engineering , University of California Berkeley , Berkeley , California 94720 , United States
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19
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Stampfli AR, Goncharenko KV, Meury M, Dubey BN, Schirmer T, Seebeck FP. An Alternative Active Site Architecture for O 2 Activation in the Ergothioneine Biosynthetic EgtB from Chloracidobacterium thermophilum. J Am Chem Soc 2019; 141:5275-5285. [PMID: 30883103 DOI: 10.1021/jacs.8b13023] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sulfoxide synthases are nonheme iron enzymes that catalyze oxidative carbon-sulfur bond formation between cysteine derivatives and N-α-trimethylhistidine as a key step in the biosynthesis of thiohistidines. The complex catalytic mechanism of this enzyme reaction has emerged as the controversial subject of several biochemical and computational studies. These studies all used the structure of the γ-glutamyl cysteine utilizing sulfoxide synthase, MthEgtB from Mycobacterium thermophilum (EC 1.14.99.50), as a structural basis. To provide an alternative model system, we have solved the crystal structure of CthEgtB from Chloracidobacterium thermophilum (EC 1.14.99.51) that utilizes cysteine as a sulfur donor. This structure reveals a completely different configuration of active site residues that are involved in oxygen binding and activation. Furthermore, comparison of the two EgtB structures enables a classification of all ergothioneine biosynthetic EgtBs into five subtypes, each characterized by unique active-site features. This active site diversity provides an excellent platform to examine the catalytic mechanism of sulfoxide synthases by comparative enzymology, but also raises the question as to why so many different solutions to the same biosynthetic problem have emerged.
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Affiliation(s)
- Anja R Stampfli
- Department of Chemistry , University of Basel , Mattenstrasse 24a , Basel 4002 , Switzerland.,Focal Area Structural Biology and Biophysics, Biozentrum , University of Basel , Basel 4056 , Switzerland
| | - Kristina V Goncharenko
- Department of Chemistry , University of Basel , Mattenstrasse 24a , Basel 4002 , Switzerland
| | - Marcel Meury
- Department of Chemistry , University of Basel , Mattenstrasse 24a , Basel 4002 , Switzerland
| | - Badri N Dubey
- Focal Area Structural Biology and Biophysics, Biozentrum , University of Basel , Basel 4056 , Switzerland
| | - Tilman Schirmer
- Focal Area Structural Biology and Biophysics, Biozentrum , University of Basel , Basel 4056 , Switzerland
| | - Florian P Seebeck
- Department of Chemistry , University of Basel , Mattenstrasse 24a , Basel 4002 , Switzerland
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20
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Del Río MP, Abril P, López JA, Sodupe M, Lledós A, Ciriano MA, Tejel C. Activating a Peroxo Ligand for C-O Bond Formation. Angew Chem Int Ed Engl 2019; 58:3037-3041. [PMID: 30589172 DOI: 10.1002/anie.201808840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/24/2018] [Indexed: 12/12/2022]
Abstract
Dioxygen activation for effective C-O bond formation in the coordination sphere of a metal is a long-standing challenge in chemistry for which the design of catalysts for oxygenations is slowed down by the complicated, and sometimes poorly understood, mechanistic panorama. In this context, olefin-peroxide complexes could be valuable models for the study of such reactions. Herein, we showcase the isolation of rare "Ir(cod)(peroxide)" complexes (cod=1,5-cyclooctadiene) from reactions with oxygen, and then the activation of the peroxide ligand for O-O bond cleavage and C-O bond formation by transfer of a hydrogen atom through proton transfer/electron transfer reactions to give 2-iradaoxetane complexes and water. 2,4,6-Trimethylphenol, 1,4-hydroquinone, and 1,4-cyclohexadiene were used as hydrogen atom donors. These reactions can be key steps in the oxy-functionalization of olefins with oxygen, and they constitute a novel mechanistic pathway for iridium, whose full reaction profile is supported by DFT calculations.
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Affiliation(s)
- M Pilar Del Río
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009-, Zaragoza, Spain
| | - Paula Abril
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009-, Zaragoza, Spain
| | - José A López
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009-, Zaragoza, Spain
| | - Mariona Sodupe
- Departament de Química, Universitat Autónoma de Barcelona, Cerdanyola del Vallès, 08193-, Barcelona, Spain
| | - Agustí Lledós
- Departament de Química, Universitat Autónoma de Barcelona, Cerdanyola del Vallès, 08193-, Barcelona, Spain
| | - Miguel A Ciriano
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009-, Zaragoza, Spain
| | - Cristina Tejel
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009-, Zaragoza, Spain
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21
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Noh H, Cho J. Synthesis, characterization and reactivity of non-heme 1st row transition metal-superoxo intermediates. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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22
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Cupric-superoxide complex that induces a catalytic aldol reaction-type C–C bond formation. Commun Chem 2019. [DOI: 10.1038/s42004-019-0115-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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23
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24
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Devi T, Lee YM, Nam W, Fukuzumi S. Aromatic hydroxylation of anthracene derivatives by a chromium( iii)-superoxo complex via proton-coupled electron transfer. Chem Commun (Camb) 2019; 55:8286-8289. [DOI: 10.1039/c9cc03245b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aromatic hydroxylation of anthracene by a mononuclear nonheme Cr(iii)-superoxo complex proceeds via the rate-determining proton-coupled electron transfer, followed by fast further oxidation to anthraquinone.
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Affiliation(s)
- Tarali Devi
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
- Faculty of Science and Engineering
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25
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Fischer AA, Lindeman SV, Fiedler AT. A synthetic model of the nonheme iron-superoxo intermediate of cysteine dioxygenase. Chem Commun (Camb) 2018; 54:11344-11347. [PMID: 30246208 PMCID: PMC6201693 DOI: 10.1039/c8cc06247a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A nonheme Fe(ii) complex (1) that models substrate-bound cysteine dioxygenase (CDO) reacts with O2 at -80 °C to yield a purple intermediate (2). Analysis with spectroscopic and computational methods determined that 2 features a thiolate-ligated Fe(iii) center bound to a superoxide radical, mimicking the putative structure of a key CDO intermediate.
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Affiliation(s)
- Anne A Fischer
- Department of Chemistry, Marquette University, 1414 W. Clybourn St., Milwaukee, WI 53233, USA.
| | - Sergey V Lindeman
- Department of Chemistry, Marquette University, 1414 W. Clybourn St., Milwaukee, WI 53233, USA.
| | - Adam T Fiedler
- Department of Chemistry, Marquette University, 1414 W. Clybourn St., Milwaukee, WI 53233, USA.
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26
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Cherrier MV, Amara P, Talbi B, Salmain M, Fontecilla-Camps JC. Crystallographic evidence for unexpected selective tyrosine hydroxylations in an aerated achiral Ru-papain conjugate. Metallomics 2018; 10:1452-1459. [PMID: 30175357 DOI: 10.1039/c8mt00160j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The X-ray structure of an aerated achiral Ru-papain conjugate has revealed the hydroxylation of two tyrosine residues found near the ruthenium ion. The most likely mechanism involves a ruthenium-bound superoxide as the reactive species responsible for the first hydroxylation and the resulting high valent Ru(iv)[double bond, length as m-dash]O species for the second one.
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Affiliation(s)
- Mickaël V Cherrier
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins, F-38000 Grenoble, France.
| | - Patricia Amara
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins, F-38000 Grenoble, France.
| | - Barisa Talbi
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 4 place Jussieu, 75005, Paris, France
| | - Michèle Salmain
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), 4 place Jussieu, 75005, Paris, France
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27
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Surendhran R, D'Arpino AA, Sciscent BY, Cannella AF, Friedman AE, MacMillan SN, Gupta R, Lacy DC. Deciphering the mechanism of O 2 reduction with electronically tunable non-heme iron enzyme model complexes. Chem Sci 2018; 9:5773-5780. [PMID: 30079187 PMCID: PMC6050603 DOI: 10.1039/c8sc01621f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/04/2018] [Indexed: 01/08/2023] Open
Abstract
A homologous series of electronically tuned 2,2',2''-nitrilotris(N-arylacetamide) pre-ligands (H3LR ) were prepared (R = NO2, CN, CF3, F, Cl, Br, Et, Me, H, OMe, NMe2) and some of their corresponding Fe and Zn species synthesized. The iron complexes react rapidly with O2, the final products of which are diferric mu-oxo bridged species. The crystal structure of the oxidized product obtained from DMA solutions contain a structural motif found in some diiron proteins. The mechanism of iron mediated O2 reduction was explored to the extent that allowed us to construct an empirically consistent rate law. A Hammett plot was constructed that enabled insightful information into the rate-determining step and hence allows for a differentiation between two kinetically equivalent O2 reduction mechanisms.
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Affiliation(s)
- Roshaan Surendhran
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , New York 14260 , USA .
| | - Alexander A D'Arpino
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , New York 14260 , USA .
| | - Bao Y Sciscent
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , New York 14260 , USA .
| | - Anthony F Cannella
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , New York 14260 , USA .
| | - Alan E Friedman
- Department of Materials Design & Innovation , University at Buffalo , SUNY , Buffalo , NY 14260 , USA
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , USA
| | - Rupal Gupta
- Department of Chemistry , College of Staten Island , City University of New York , Staten Island , NY 10314 , USA
| | - David C Lacy
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , New York 14260 , USA .
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28
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Devi T, Lee YM, Nam W, Fukuzumi S. Remarkable Acid Catalysis in Proton-Coupled Electron-Transfer Reactions of a Chromium(III)-Superoxo Complex. J Am Chem Soc 2018; 140:8372-8375. [DOI: 10.1021/jacs.8b02303] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Tarali Devi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, People’s Republic of China
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
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29
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30
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Tian G, Su H, Liu Y. Mechanism of Sulfoxidation and C–S Bond Formation Involved in the Biosynthesis of Ergothioneine Catalyzed by Ergothioneine Synthase (EgtB). ACS Catal 2018. [DOI: 10.1021/acscatal.8b01473] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ge Tian
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, People’s Republic of China
| | - Hao Su
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, People’s Republic of China
| | - Yongjun Liu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, People’s Republic of China
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31
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Zhang LL, Wang XY, Jiang KY, Zhao BY, Yan HM, Zhang XY, Zhang ZX, Guo Z, Che CM. A theoretical study on the oxidation of alkenes to aldehydes catalyzed by ruthenium porphyrins using O 2 as the sole oxidant. Dalton Trans 2018; 47:5286-5297. [PMID: 29569676 DOI: 10.1039/c8dt00614h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Density functional theory (DFT) calculations were used to study the ruthenium porphyrin-catalyzed oxidation of styrene to generate an aldehyde. The results indicate that two reactive oxidants, dioxoruthenium and monooxoruthenium-superoxo porphyrins, participate in the catalytic oxidation. In the mechanism, the resultant monooxoruthenium porphyrin acts in the tandem epoxide isomerization (E-I) to selectively yield an aldehyde and generate a dioxoruthenium porphyrin, thereby triggering new oxidation reaction cycles. In this calculation, several key elements responsible for the observed oxidative ability have been established by using Frontier molecular orbital (FMO) theory, natural bond orbital (NBO) analysis, etc., which include the reaction energy, the spin exchange effect, the spin-state conversion process, and the energy level of the lowest unoccupied molecular orbitals (LUMOs) of the reactive oxidants. The comparative oxidative abilities of the ruthenium-oxo/superoxo compounds with different axial ligands are also investigated. The results suggest that the ruthenium-oxo/superoxo species featuring a chlorine axial ligand is more reactive than that substituted with oxygen. This tuneable reactivity can be understood when considering the different electronic characters of the two ligands and the effective atomic number rule (EAN).
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Affiliation(s)
- Lin-Lin Zhang
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Xiang-Yun Wang
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Kun-Yao Jiang
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Bing-Yuan Zhao
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Hui-Min Yan
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Xiao-Yun Zhang
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Zhu-Xia Zhang
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Zhen Guo
- College of Material Science & Engineering, Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Shanxi, 030024, P. R. China.
| | - Chi-Ming Che
- Department of Chemistry, the University of Hong Kong, Hong Kong, P. R. China.
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32
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Jasniewski AJ, Que L. Dioxygen Activation by Nonheme Diiron Enzymes: Diverse Dioxygen Adducts, High-Valent Intermediates, and Related Model Complexes. Chem Rev 2018; 118:2554-2592. [PMID: 29400961 PMCID: PMC5920527 DOI: 10.1021/acs.chemrev.7b00457] [Citation(s) in RCA: 304] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A growing subset of metalloenzymes activates dioxygen with nonheme diiron active sites to effect substrate oxidations that range from the hydroxylation of methane and the desaturation of fatty acids to the deformylation of fatty aldehydes to produce alkanes and the six-electron oxidation of aminoarenes to nitroarenes in the biosynthesis of antibiotics. A common feature of their reaction mechanisms is the formation of O2 adducts that evolve into more reactive derivatives such as diiron(II,III)-superoxo, diiron(III)-peroxo, diiron(III,IV)-oxo, and diiron(IV)-oxo species, which carry out particular substrate oxidation tasks. In this review, we survey the various enzymes belonging to this unique subset and the mechanisms by which substrate oxidation is carried out. We examine the nature of the reactive intermediates, as revealed by X-ray crystallography and the application of various spectroscopic methods and their associated reactivity. We also discuss the structural and electronic properties of the model complexes that have been found to mimic salient aspects of these enzyme active sites. Much has been learned in the past 25 years, but key questions remain to be answered.
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Affiliation(s)
- Andrew J. Jasniewski
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
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33
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Peck SC, Wang C, Dassama LMK, Zhang B, Guo Y, Rajakovich LJ, Bollinger JM, Krebs C, van der Donk WA. O-H Activation by an Unexpected Ferryl Intermediate during Catalysis by 2-Hydroxyethylphosphonate Dioxygenase. J Am Chem Soc 2017; 139:2045-2052. [PMID: 28092705 PMCID: PMC5302023 DOI: 10.1021/jacs.6b12147] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Activation
of O–H bonds by inorganic metal-oxo complexes
has been documented, but no cognate enzymatic process is known. Our
mechanistic analysis of 2-hydroxyethylphosphonate dioxygenase
(HEPD), which cleaves the C1–C2 bond of its substrate to afford
hydroxymethylphosphonate on the biosynthetic pathway to
the commercial herbicide phosphinothricin, uncovered an example
of such an O–H-bond-cleavage event. Stopped-flow UV–visible
absorption and freeze-quench Mössbauer experiments identified
a transient iron(IV)-oxo (ferryl) complex. Maximal accumulation of
the intermediate required both the presence of deuterium in the substrate
and, importantly, the use of 2H2O as solvent.
The ferryl complex forms and decays rapidly enough to be on the catalytic
pathway. To account for these unanticipated results, a new mechanism
that involves activation of an O–H bond by the ferryl complex
is proposed. This mechanism accommodates all available data on the
HEPD reaction.
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Affiliation(s)
- Spencer C Peck
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign , 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | - Chen Wang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Laura M K Dassama
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Bo Zhang
- Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Yisong Guo
- Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Lauren J Rajakovich
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - J Martin Bollinger
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.,Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Carsten Krebs
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.,Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Wilfred A van der Donk
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign , 1206 West Gregory Drive, Urbana, Illinois 61801, United States
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34
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Kal S, Que L. Dioxygen activation by nonheme iron enzymes with the 2-His-1-carboxylate facial triad that generate high-valent oxoiron oxidants. J Biol Inorg Chem 2017; 22:339-365. [PMID: 28074299 DOI: 10.1007/s00775-016-1431-2] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/13/2016] [Indexed: 11/24/2022]
Abstract
The 2-His-1-carboxylate facial triad is a widely used scaffold to bind the iron center in mononuclear nonheme iron enzymes for activating dioxygen in a variety of oxidative transformations of metabolic significance. Since the 1990s, over a hundred different iron enzymes have been identified to use this platform. This structural motif consists of two histidines and the side chain carboxylate of an aspartate or a glutamate arranged in a facial array that binds iron(II) at the active site. This triad occupies one face of an iron-centered octahedron and makes the opposite face available for the coordination of O2 and, in many cases, substrate, allowing the tailoring of the iron-dioxygen chemistry to carry out a plethora of diverse reactions. Activated dioxygen-derived species involved in the enzyme mechanisms include iron(III)-superoxo, iron(III)-peroxo, and high-valent iron(IV)-oxo intermediates. In this article, we highlight the major crystallographic, spectroscopic, and mechanistic advances of the past 20 years that have significantly enhanced our understanding of the mechanisms of O2 activation and the key roles played by iron-based oxidants.
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Affiliation(s)
- Subhasree Kal
- Department of Chemistry, Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Lawrence Que
- Department of Chemistry, Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA.
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35
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Zhang J, Yang H, Sun T, Chen Z, Yin G. Nonredox Metal-Ions-Enhanced Dioxygen Activation by Oxidovanadium(IV) Complexes toward Hydrogen Atom Abstraction. Inorg Chem 2017; 56:834-844. [DOI: 10.1021/acs.inorgchem.6b02277] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jisheng Zhang
- School of Chemistry and Chemical Engineering,
Key Laboratory of Material Chemistry for Energy Conversion and Storage,
Ministry of Education, and Hubei Key Laboratory of Material Chemistry
and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Hang Yang
- School of Chemistry and Chemical Engineering,
Key Laboratory of Material Chemistry for Energy Conversion and Storage,
Ministry of Education, and Hubei Key Laboratory of Material Chemistry
and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Tingting Sun
- School of Chemistry and Chemical Engineering,
Key Laboratory of Material Chemistry for Energy Conversion and Storage,
Ministry of Education, and Hubei Key Laboratory of Material Chemistry
and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Zhuqi Chen
- School of Chemistry and Chemical Engineering,
Key Laboratory of Material Chemistry for Energy Conversion and Storage,
Ministry of Education, and Hubei Key Laboratory of Material Chemistry
and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Guochuan Yin
- School of Chemistry and Chemical Engineering,
Key Laboratory of Material Chemistry for Energy Conversion and Storage,
Ministry of Education, and Hubei Key Laboratory of Material Chemistry
and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
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36
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Abstract
Organophosphonic acids are unique as natural products in terms of stability and mimicry. The C-P bond that defines these compounds resists hydrolytic cleavage, while the phosphonyl group is a versatile mimic of transition-states, intermediates, and primary metabolites. This versatility may explain why a variety of organisms have extensively explored the use organophosphonic acids as bioactive secondary metabolites. Several of these compounds, such as fosfomycin and bialaphos, figure prominently in human health and agriculture. The enzyme reactions that create these molecules are an interesting mix of chemistry that has been adopted from primary metabolism as well as those with no chemical precedent. Additionally, the phosphonate moiety represents a source of inorganic phosphate to microorganisms that live in environments that lack this nutrient; thus, unusual enzyme reactions have also evolved to cleave the C-P bond. This review is a comprehensive summary of the occurrence and function of organophosphonic acids natural products along with the mechanisms of the enzymes that synthesize and catabolize these molecules.
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Affiliation(s)
- Geoff P Horsman
- Department of Chemistry and Biochemistry, Wilfrid Laurier University , Waterloo, Ontario N2L 3C5, Canada
| | - David L Zechel
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
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37
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Peck SC, van der Donk WA. Go it alone: four-electron oxidations by mononuclear non-heme iron enzymes. J Biol Inorg Chem 2016; 22:381-394. [PMID: 27783267 DOI: 10.1007/s00775-016-1399-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 10/11/2016] [Indexed: 10/20/2022]
Abstract
This review discusses the current mechanistic understanding of a group of mononuclear non-heme iron-dependent enzymes that catalyze four-electron oxidation of their organic substrates without the use of any cofactors or cosubstrates. One set of enzymes acts on α-ketoacid-containing substrates, coupling decarboxylation to oxygen activation. This group includes 4-hydroxyphenylpyruvate dioxygenase, 4-hydroxymandelate synthase, and CloR involved in clorobiocin biosynthesis. A second set of enzymes acts on substrates containing a thiol group that coordinates to the iron. This group is comprised of isopenicillin N synthase, thiol dioxygenases, and enzymes involved in the biosynthesis of ergothioneine and ovothiol. The final group of enzymes includes HEPD and MPnS that both carry out the oxidative cleavage of the carbon-carbon bond of 2-hydroxyethylphosphonate but generate different products. Commonalities amongst many of these enzymes are discussed and include the initial substrate oxidation by a ferric-superoxo-intermediate and a second oxidation by a ferryl species.
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Affiliation(s)
- Spencer C Peck
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL, 61801, USA.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL, 61801, USA
| | - Wilfred A van der Donk
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL, 61801, USA. .,Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL, 61801, USA.
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38
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Tamanaha EY, Zhang B, Guo Y, Chang WC, Barr EW, Xing G, St Clair J, Ye S, Neese F, Bollinger JM, Krebs C. Spectroscopic Evidence for the Two C-H-Cleaving Intermediates of Aspergillus nidulans Isopenicillin N Synthase. J Am Chem Soc 2016; 138:8862-74. [PMID: 27193226 PMCID: PMC4956533 DOI: 10.1021/jacs.6b04065] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The enzyme isopenicillin N synthase (IPNS) installs the β-lactam and thiazolidine rings of the penicillin core into the linear tripeptide l-δ-aminoadipoyl-l-Cys-d-Val (ACV) on the pathways to a number of important antibacterial drugs. A classic set of enzymological and crystallographic studies by Baldwin and co-workers established that this overall four-electron oxidation occurs by a sequence of two oxidative cyclizations, with the β-lactam ring being installed first and the thiazolidine ring second. Each phase requires cleavage of an aliphatic C-H bond of the substrate: the pro-S-CCys,β-H bond for closure of the β-lactam ring, and the CVal,β-H bond for installation of the thiazolidine ring. IPNS uses a mononuclear non-heme-iron(II) cofactor and dioxygen as cosubstrate to cleave these C-H bonds and direct the ring closures. Despite the intense scrutiny to which the enzyme has been subjected, the identities of the oxidized iron intermediates that cleave the C-H bonds have been addressed only computationally; no experimental insight into their geometric or electronic structures has been reported. In this work, we have employed a combination of transient-state-kinetic and spectroscopic methods, together with the specifically deuterium-labeled substrates, A[d2-C]V and AC[d8-V], to identify both C-H-cleaving intermediates. The results show that they are high-spin Fe(III)-superoxo and high-spin Fe(IV)-oxo complexes, respectively, in agreement with published mechanistic proposals derived computationally from Baldwin's founding work.
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Affiliation(s)
- Esta Y. Tamanaha
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Bo Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Yisong Guo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Wei-chen Chang
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Eric W. Barr
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gang Xing
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jennifer St Clair
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Shengfa Ye
- Max-Planck Institute for Chemical Energy Conversion, Mülheim a. d. Ruhr, Germany
| | - Frank Neese
- Max-Planck Institute for Chemical Energy Conversion, Mülheim a. d. Ruhr, Germany
| | - J. Martin Bollinger
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Carsten Krebs
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
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39
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Ellington BR, Paul B, Das D, Vitek AK, Zimmerman PM, Marsh ENG. An Unusual Iron-Dependent Oxidative Deformylation Reaction Providing Insight into Hydrocarbon Biosynthesis in Nature. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00592] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Benjamin R. Ellington
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Bishwajit Paul
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Debasis Das
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andrew K. Vitek
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M. Zimmerman
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - E. Neil G. Marsh
- Department of Biological Chemistry and ‡Department of
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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40
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Catalytic strategies of the non-heme iron dependent oxygenases and their roles in plant biology. Curr Opin Chem Biol 2016; 31:126-35. [PMID: 27015291 PMCID: PMC4879150 DOI: 10.1016/j.cbpa.2016.02.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/25/2016] [Accepted: 02/26/2016] [Indexed: 12/18/2022]
Abstract
Current evidence for iron-oxo reactive intermediates is reviewed. In crystallo intermediates detected in a native extradiol dioxygenase reaction. Carotenoid cleavage dioxygenases catalyse strigolactone biosynthesis. Identification of plant cysteine oxidases involved in the plant hypoxic response. Applications of enzyme manipulation to plant biology and agriculture are discussed.
Non-heme iron-dependent oxygenases catalyse the incorporation of O2 into a wide range of biological molecules and use diverse strategies to activate their substrates. Recent kinetic studies, including in crystallo, have provided experimental support for some of the intermediates used by different subclasses of this enzyme family. Plant non-heme iron-dependent oxygenases have diverse and important biological roles, including in growth signalling, stress responses and secondary metabolism. Recently identified roles include in strigolactone biosynthesis, O-demethylation in morphine biosynthesis and regulating the stability of hypoxia-responsive transcription factors. We discuss current structural and mechanistic understanding of plant non-heme iron oxygenases, and how their chemical/genetic manipulation could have agricultural benefit, for example, for improved yield, stress tolerance or herbicide development.
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41
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Sun Y, Tang H, Chen K, Hu L, Yao J, Shaik S, Chen H. Two-State Reactivity in Low-Valent Iron-Mediated C–H Activation and the Implications for Other First-Row Transition Metals. J Am Chem Soc 2016; 138:3715-30. [DOI: 10.1021/jacs.5b12150] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yihua Sun
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Hao Tang
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Kejuan Chen
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Lianrui Hu
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Jiannian Yao
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Sason Shaik
- Institute
of Chemistry and the Lise Meitner-Minerva Center for Computational
Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Hui Chen
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
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42
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Anneser MR, Haslinger S, Pöthig A, Cokoja M, D'Elia V, Högerl MP, Basset JM, Kühn FE. Binding of molecular oxygen by an artificial heme analogue: investigation on the formation of an Fe–tetracarbene superoxo complex. Dalton Trans 2016; 45:6449-55. [DOI: 10.1039/c6dt00538a] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity of a heme-like organometallic Fe–NHC complex with O2 is studied. The formation of a superoxo Fe(iii) intermediate is observed. The reactivity of the intermediate in acetone and acetonitrile is described and the products are identified.
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Affiliation(s)
- Markus R. Anneser
- Chair of Inorganic Chemistry/Molecular Catalysis
- Catalysis Research Center
- Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry
- D-85747 Garching bei München
- Germany
| | - Stefan Haslinger
- Chair of Inorganic Chemistry/Molecular Catalysis
- Catalysis Research Center
- Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry
- D-85747 Garching bei München
- Germany
| | - Alexander Pöthig
- Chair of Inorganic Chemistry/Molecular Catalysis
- Catalysis Research Center
- Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry
- D-85747 Garching bei München
- Germany
| | - Mirza Cokoja
- Chair of Inorganic Chemistry/Molecular Catalysis
- Catalysis Research Center
- Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry
- D-85747 Garching bei München
- Germany
| | - Valerio D'Elia
- KAUST Catalysis Center
- King Abdullah University of Science and Technology
- Thuwal
- Kingdom of Saudi Arabia
- Department of Materials Science and Engineering
| | - Manuel P. Högerl
- KAUST Catalysis Center
- King Abdullah University of Science and Technology
- Thuwal
- Kingdom of Saudi Arabia
| | - Jean-Marie Basset
- KAUST Catalysis Center
- King Abdullah University of Science and Technology
- Thuwal
- Kingdom of Saudi Arabia
| | - Fritz E. Kühn
- Chair of Inorganic Chemistry/Molecular Catalysis
- Catalysis Research Center
- Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry
- D-85747 Garching bei München
- Germany
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43
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Roy S, Kästner J. QM/MM-Simulationen ergeben synergetische Substrat- und Sauerstoffaktivierung in Salicylat-Dioxygenase. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Subhendu Roy
- Institut für Theoretische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Johannes Kästner
- Institut für Theoretische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
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44
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Roy S, Kästner J. Synergistic Substrate and Oxygen Activation in Salicylate Dioxygenase Revealed by QM/MM Simulations. Angew Chem Int Ed Engl 2015; 55:1168-72. [DOI: 10.1002/anie.201506363] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/18/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Subhendu Roy
- Institute for Theoretical Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Johannes Kästner
- Institute for Theoretical Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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45
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Goo YR, Maity AC, Cho KB, Lee YM, Seo MS, Park YJ, Cho J, Nam W. Tuning the Reactivity of Chromium(III)-Superoxo Species by Coordinating Axial Ligands. Inorg Chem 2015; 54:10513-20. [PMID: 26486819 DOI: 10.1021/acs.inorgchem.5b02068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metal-superoxo species have attracted much attention recently as key intermediates in enzymatic and biomimetic oxidation reactions. The effect(s) of axial ligands on the chemical properties of metal-superoxo complexes has never been explored previously. In this study, we synthesized and characterized chromium(III)-superoxo complexes bearing TMC derivatives with pendant pyridine and imidazole donors, such as [Cr(III)(O2)(TMC-Py)](2+) (1, TMC-Py = 4,8,11-trimethyl-1-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) and [Cr(III)(O2)(TMC-Im)](2+) (2, TMC-Im = 4,8,11-trimethyl-1-(2-methylimidazolmethyl)-1,4,8,11-tetraazacyclotetradecane). The reactivity of chromium(III)-superoxo complexes binding different axial ligands, such as 1, 2, and [Cr(III)(O2)(TMC)(Cl)](+) (3, TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), was then investigated in C-H bond activation and oxygen atom transfer reactions. Kinetic studies revealed that the reactivity of the Cr(III)-superoxo complexes depends on the axial ligands, showing the reactivity order of 1 > 2 > 3 in those electrophilic oxidation reactions. It was also shown that there is a good correlation between the reactivity of the chromium(III)-superoxo complexes and their redox potentials, in which the redox potentials of the chromium(III)-superoxo complexes are in the order 1 > 2 > 3. DFT calculations reproduced the reactivity order between 1 and 3 in both C-H bond activation and oxygen atom transfer reactions, and the latter reaction is described using orbital interactions. The calculations are also in agreement with the experimentally obtained redox potentials. The present results provide the first example showing that the reactivity of metal-superoxo species can be tuned by the electron-donating ability of axial ligands bound trans to the metal-superoxo moiety.
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Affiliation(s)
- Yi Re Goo
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Annada C Maity
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Kyung-Bin Cho
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Young Jun Park
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Jaeheung Cho
- Department of Emerging Materials Science, DGIST , Daegu 42988, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
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46
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Lanz ND, Rectenwald JM, Wang B, Kakar ES, Laremore TN, Booker SJ, Silakov A. Characterization of a Radical Intermediate in Lipoyl Cofactor Biosynthesis. J Am Chem Soc 2015; 137:13216-9. [PMID: 26390103 DOI: 10.1021/jacs.5b04387] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lipoyl synthase (LipA) catalyzes the final step in the biosynthesis of the lipoyl cofactor, the insertion of two sulfur atoms at C6 and C8 of an n-octanoyl chain. LipA is a member of the radical S-adenosylmethionine (SAM) superfamily of enzymes and uses two [4Fe-4S] clusters to catalyze its transformation. One cluster binds in contact with SAM and donates the requisite electron for the reductive cleavage of SAM to generate two 5'-deoxyadenosyl 5'-radicals, which abstract hydrogen atoms from C6 and C8 of the substrate. By contrast, the second, auxiliary [4Fe-4S] cluster, has been hypothesized to serve as the sulfur donor in the reaction. Such a sacrificial role for an iron-sulfur cluster during catalysis has not been universally accepted. Use of a conjugated 2,4-hexadienoyl-containing substrate analogue has allowed the substrate radical to be trapped and characterized by continuous-wave and pulsed electron paramagnetic resonance methods. Here we report the observation of a (57)Fe hyperfine coupling interaction with the paramagnetic signal, which indicates that the iron-sulfur cluster of LipA and its substrate are within bonding distance.
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Affiliation(s)
- Nicholas D Lanz
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Justin M Rectenwald
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Bo Wang
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Elizabeth S Kakar
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Tatiana N Laremore
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Squire J Booker
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Alexey Silakov
- Departments of †Chemistry and ‡Biochemistry and Molecular Biology and §The Huck Institutes of the Life Sciences, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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47
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Abstract
Mononuclear nonheme iron-oxygen species, such as iron-superoxo, -peroxo, -hydroperoxo, and -oxo, are key intermediates involved in dioxygen activation and oxidation reactions catalyzed by nonheme iron enzymes. Because these iron-oxygen intermediates are short-lived due to their thermal instability and high reactivity, it is challenging to investigate their structural and spectroscopic properties and reactivity in the catalytic cycles of the enzymatic reactions themselves. One way to approach such problems is to synthesize biomimetic iron-oxygen complexes and to tune their geometric and electronic structures for structural characterization and reactivity studies. Indeed, a number of biologically important iron-oxygen species, such as mononuclear nonheme iron(III)-superoxo, iron(III)-peroxo, iron(III)-hydroperoxo, iron(IV)-oxo, and iron(V)-oxo complexes, were synthesized recently, and the first X-ray crystal structures of iron(III)-superoxo, iron(III)-peroxo, and iron(IV)-oxo complexes in nonheme iron models were successfully obtained. Thus, our understanding of iron-oxygen intermediates in biological reactions has been aided greatly from the studies of the structural and spectroscopic properties and the reactivities of the synthetic biomimetic analogues. In this Account, we describe our recent results on the synthesis and characterization of mononuclear nonheme iron-oxygen complexes bearing simple macrocyclic ligands, such as N-tetramethylated cyclam ligand (TMC) and tetraamido macrocyclic ligand (TAML). In the case of iron-superoxo complexes, an iron(III)-superoxo complex, [(TAML)Fe(III)(O2)](2-), is described, including its crystal structure and reactivities in electrophilic and nucleophilic oxidative reactions, and its properties are compared with those of a chromium(III)-superoxo complex, [(TMC)Cr(III)(O2)(Cl)](+), with respect to its reactivities in hydrogen atom transfer (HAT) and oxygen atom transfer (OAT) reactions. In the case of iron-peroxo intermediates, an X-ray crystal structure of an iron(III)-peroxo complex binding the peroxo ligand in a side-on (η(2)) fashion, [(TMC)Fe(III)(O2)](+), is described. In addition, iron(III)-peroxo complexes binding redox-inactive metal ions are described and discussed in light of the role of redox-inactive metal ions in O-O bond activation in cytochrome c oxidase and O2-evolution in photosystem II. In the case of iron-hydroperoxo intermediates, mononuclear nonheme iron(III)-hydroperoxo complexes can be generated upon protonation of iron(III)-peroxo complexes or by hydrogen atom abstraction (HAA) of hydrocarbon C-H bonds by iron(III)-superoxo complexes. Reactivities of the iron(III)-hydroperoxo complexes in both electrophilic and nucleophilic oxidative reactions are described along with a discussion of O-O bond cleavage mechanisms. In the last section of this Account, a brief summary is presented of developments in mononuclear nonheme iron(IV)-oxo complexes since the first structurally characterized iron(IV)-oxo complex, [(TMC)Fe(IV)(O)](2+), was reported. Although the field of nonheme iron-oxygen intermediates (e.g., Fe-O2, Fe-O2H, and Fe-O) has been developed greatly through intense synthetic, structural, spectroscopic, reactivity, and theoretical studies in the communities of bioinorganic and biomimetic chemistry over the past 10 years, there is still much to be explored in trapping, characterizing, and understanding the chemical properties of the key iron-oxygen intermediates involved in dioxygen activation and oxidation reactions by nonheme iron enzymes and their biomimetic compounds.
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Affiliation(s)
- Wonwoo Nam
- Department of Chemistry and
Nano Science, Ewha Womans University, Seoul 120-750, Korea
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48
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Wang B, Lee YM, Seo MS, Nam W. Mononuclear Nonheme Iron(III)-Iodosylarene and High-Valent Iron-Oxo Complexes in Olefin Epoxidation Reactions. Angew Chem Int Ed Engl 2015; 54:11740-4. [PMID: 26273792 DOI: 10.1002/anie.201505796] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/06/2022]
Abstract
High-spin iron(III)-iodosylarene complexes are highly reactive in the epoxidation of olefins, in which epoxides are formed as the major products with high stereospecificity and enantioselectivity. The reactivity of the iron(III)-iodosylarene intermediates is much greater than that of the corresponding iron(IV)-oxo complex in these reactions. The iron(III)-iodosylarene species-not high-valent iron(IV)-oxo and iron(V)-oxo species-are also shown to be the active oxidants in catalytic olefin epoxidation reactions. The present results are discussed in light of the long-standing controversy on the one oxidant versus multiple oxidants hypothesis in oxidation reactions.
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Affiliation(s)
- Bin Wang
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea)
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea)
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea)
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea).
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49
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Wang B, Lee YM, Seo MS, Nam W. Mononuclear Nonheme Iron(III)-Iodosylarene and High-Valent Iron-Oxo Complexes in Olefin Epoxidation Reactions. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505796] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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50
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Zhu H, Peck SC, Bonnot F, van der Donk WA, Klinman JP. Oxygen-18 Kinetic Isotope Effects of Nonheme Iron Enzymes HEPD and MPnS Support Iron(III) Superoxide as the Hydrogen Abstraction Species. J Am Chem Soc 2015; 137:10448-51. [PMID: 26267117 PMCID: PMC4970508 DOI: 10.1021/jacs.5b03907] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Nonheme
iron oxygenases that carry out four-electron oxidations
of substrate have been proposed to employ iron(III) superoxide species
to initiate this reaction [Paria, S.; Que, L.; Paine, T. K. Angew. Chem. Int. Ed.2011, 50, 11129]. Here we report experimental evidence in support of this
proposal. 18O KIEs were measured for two recently discovered
mononuclear nonheme iron oxygenases: hydroxyethylphosphonate dioxygenase
(HEPD) and methylphosphonate synthase (MPnS). Competitive 18O KIEs measured with deuterated substrates are larger than those
measured with unlabeled substrates, which indicates that C–H
cleavage must occur before an irreversible reductive step at molecular
oxygen. A similar observation was previously used to implicate copper(II)
superoxide in the H-abstraction reactions catalyzed by dopamine β-monooxygenase
[Tian, G. C.; Klinman, J. P. J. Am. Chem. Soc.1993, 115, 8891] and peptidylglycine α-hydroxylating
monooxygenase [Francisco, W. A.; Blackburn, N. J.; Klinman, J. P. Biochemistry2003, 42, 1813].
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Affiliation(s)
| | - Spencer C Peck
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign , 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | | | - Wilfred A van der Donk
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign , 1206 West Gregory Drive, Urbana, Illinois 61801, United States
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