1
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Desbois A, Valton J, Moreau Y, Torelli S, Nivière V. Conformational H-bonding modulation of the iron active site cysteine ligand of superoxide reductase: absorption and resonance Raman studies. Phys Chem Chem Phys 2021; 23:4636-4645. [PMID: 33527107 DOI: 10.1039/d0cp03898a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Superoxide reductases (SORs) are mononuclear non-heme iron enzymes involved in superoxide radical detoxification in some microorganisms. Their atypical active site is made of an iron atom pentacoordinated by four equatorial nitrogen atoms from histidine residues and one axial sulfur atom from a cysteinate residue, which plays a central role in catalysis. In most SORs, the residue immediately following the cysteinate ligand is an asparagine, which belongs to the second coordination sphere and is expected to have a critical influence on the properties of the active site. In this work, in order to investigate the role of this asparagine residue in the Desulfoarculus baarsii enzyme (Asn117), we carried out, in comparison with the wild-type enzyme, absorption and resonance Raman (RR) studies on a SOR mutant in which Asn117 was changed into an alanine. RR analysis was developed in order to assign the different bands using excitation in the (Cys116)-S-→ Fe3+ charge transfer band. By investigating the correlation between the (Cys116)-S-→ Fe3+ charge transfer band maximum with the frequency of each RR band in different SOR forms, we assessed the contribution of the ν(Fe-S) vibration among the different RR bands. The data showed that Asn117, by making hydrogen bond interactions with Lys74 and Tyr76, allows a rigidification of the backbone of the Cys116 ligand, as well as that of the neighboring residues Ile118 and His119. Such a structural role of Asn117 has a deep impact on the S-Fe bond. It results in a tight control of the H-bond distance between the Ile118 and His119 NH peptidic moiety with the cysteine sulfur ligand, which in turn enables fine-tuning of the S-Fe bond strength, an essential property for the SOR active site. This study illustrates the intricate roles of second coordination sphere residues to adjust the ligand to metal bond properties in the active site of metalloenzymes.
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Affiliation(s)
- Alain Desbois
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91198, Gif-sur-Yvette Cedex, France
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2
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Martins MC, Romão CV, Folgosa F, Borges PT, Frazão C, Teixeira M. How superoxide reductases and flavodiiron proteins combat oxidative stress in anaerobes. Free Radic Biol Med 2019; 140:36-60. [PMID: 30735841 DOI: 10.1016/j.freeradbiomed.2019.01.051] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/14/2019] [Accepted: 01/31/2019] [Indexed: 12/31/2022]
Abstract
Microbial anaerobes are exposed in the natural environment and in their hosts, even if transiently, to fluctuating concentrations of oxygen and its derived reactive species, which pose a considerable threat to their anoxygenic lifestyle. To counteract these stressful conditions, they contain a multifaceted array of detoxifying systems that, in conjugation with cellular repairing mechanisms and in close crosstalk with metal homeostasis, allow them to survive in the presence of O2 and reactive oxygen species. Some of these systems are shared with aerobes, but two families of enzymes emerged more recently that, although not restricted to anaerobes, are predominant in anaerobic microbes. These are the iron-containing superoxide reductases, and the flavodiiron proteins, endowed with O2 and/or NO reductase activities, which are the subject of this Review. A detailed account of their physicochemical, physiological and molecular mechanisms will be presented, highlighting their unique properties in allowing survival of anaerobes in oxidative stress conditions, and comparing their properties with the most well-known detoxifying systems.
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Affiliation(s)
- Maria C Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Célia V Romão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Filipe Folgosa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Patrícia T Borges
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Carlos Frazão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Miguel Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal.
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3
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Horch M. Rational redox tuning of transition metal sites: learning from superoxide reductase. Chem Commun (Camb) 2019; 55:9148-9151. [PMID: 31304493 DOI: 10.1039/c9cc04004h] [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
Using superoxide reductase as a model system, a computational approach reveals how histidine tautomerism tunes the redox properties of metalloenzymes to enable their catalytic function. Inspired by these experimentally inaccessible insights, non-canonical histidine congeners are introduced as new versatile tools for the rational engineering of biological transition metal sites.
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Affiliation(s)
- Marius Horch
- Department of Chemistry and York Biomedical Research Institute, University of York, Heslington, York, YO10 5DD, UK.
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4
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Romão CV, Matias PM, Sousa CM, Pinho FG, Pinto AF, Teixeira M, Bandeiras TM. Insights into the Structures of Superoxide Reductases from the Symbionts Ignicoccus hospitalis and Nanoarchaeum equitans. Biochemistry 2018; 57:5271-5281. [PMID: 29939726 DOI: 10.1021/acs.biochem.8b00334] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Superoxide reductases (SORs) are enzymes that detoxify the superoxide anion through its reduction to hydrogen peroxide and exist in both prokaryotes and eukaryotes. The substrate is transformed at an iron catalytic center, pentacoordinated in the ferrous state by four histidines and one cysteine. SORs have a highly conserved motif, (E)(K)HxP-, in which the glutamate is associated with a redox-driven structural change, completing the octahedral coordination of the iron in the ferric state, whereas the lysine may be responsible for stabilization and donation of a proton to catalytic intermediates. We aimed to understand at the structural level the role of these two residues, by determining the X-ray structures of the SORs from the hyperthermophilic archaea Ignicoccus hospitalis and Nanoarchaeum equitans that lack the quasi-conserved lysine and glutamate, respectively, but have catalytic rate constants similar to those of the canonical enzymes, as we previously demonstrated. Furthermore, we have determined the crystal structure of the E23A mutant of I. hospitalis SOR, which mimics several enzymes that lack both residues. The structures revealed distinct structural arrangements of the catalytic center that simulate several catalytic cycle intermediates, namely, the reduced and the oxidized forms, and the glutamate-free and deprotonated ferric forms. Moreover, the structure of the I. hospitalis SOR provides evidence for the presence of an alternative lysine close to the iron center in the reduced state that may be a functional substitute for the "canonical" lysine.
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Affiliation(s)
- Célia V Romão
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , Av. da República , 2780-157 Oeiras , Portugal
| | - Pedro M Matias
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , Av. da República , 2780-157 Oeiras , Portugal.,iBET , Instituto de Biologia Experimental e Tecnológica , Apartado 12 , 2781-901 Oeiras , Portugal
| | - Cristiana M Sousa
- iBET , Instituto de Biologia Experimental e Tecnológica , Apartado 12 , 2781-901 Oeiras , Portugal
| | - Filipa G Pinho
- iBET , Instituto de Biologia Experimental e Tecnológica , Apartado 12 , 2781-901 Oeiras , Portugal
| | - Ana F Pinto
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , Av. da República , 2780-157 Oeiras , Portugal
| | - Miguel Teixeira
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , Av. da República , 2780-157 Oeiras , Portugal
| | - Tiago M Bandeiras
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , Av. da República , 2780-157 Oeiras , Portugal.,iBET , Instituto de Biologia Experimental e Tecnológica , Apartado 12 , 2781-901 Oeiras , Portugal
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5
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David R, Jamet H, Nivière V, Moreau Y, Milet A. Iron Hydroperoxide Intermediate in Superoxide Reductase: Protonation or Dissociation First? MM Dynamics and QM/MM Metadynamics Study. J Chem Theory Comput 2017; 13:2987-3004. [DOI: 10.1021/acs.jctc.7b00126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rolf David
- DCM, Univ. Grenoble Alpes, F-38000 Grenoble, France
- CNRS, DCM, F-38000, Grenoble, France
- Laboratoire
de Chimie et Biologie des Métaux, CEA/DRF/BIG/CBM/MCT, CNRS
UMR 5249, Université Grenoble Alpes, Grenoble, France
| | - Hélène Jamet
- DCM, Univ. Grenoble Alpes, F-38000 Grenoble, France
- CNRS, DCM, F-38000, Grenoble, France
| | - Vincent Nivière
- Laboratoire
de Chimie et Biologie des Métaux, CEA/DRF/BIG/CBM/BioCat, CNRS
UMR 5249, Université Grenoble Alpes, Grenoble, France
| | - Yohann Moreau
- Laboratoire
de Chimie et Biologie des Métaux, CEA/DRF/BIG/CBM/MCT, CNRS
UMR 5249, Université Grenoble Alpes, Grenoble, France
| | - Anne Milet
- DCM, Univ. Grenoble Alpes, F-38000 Grenoble, France
- CNRS, DCM, F-38000, Grenoble, France
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6
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Attia AAA, Cioloboc D, Lupan A, Silaghi-Dumitrescu R. Multiconfigurational and DFT analyses of the electromeric formulation and UV-vis absorption spectra of the superoxide adduct of ferrous superoxide reductase. J Inorg Biochem 2016; 165:49-53. [PMID: 27768962 DOI: 10.1016/j.jinorgbio.2016.09.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 09/14/2016] [Accepted: 09/29/2016] [Indexed: 11/29/2022]
Abstract
The putative initial adduct of ferrous superoxide reductase (SOR) with superoxide has been alternatively formulated as ferric-peroxo or ferrous-superoxo. The ~600-nm UV-vis absorption band proposed to be assigned to this adduct (either as sole intermediate in the SOR catalytic cycle, or as one of the two intermediates) has recently been interpreted as due to a ligand-to-metal charge transfer, involving thiolate and superoxide in a ferrous complex, contrary to an alternative assignment as a predominantly cysteine thiolate-to-ferric charge transfer in a ferric-peroxo electromer. In an attempt to clarify the electromeric formulation of this adduct, we report a computational study using a multiconfigurational complete active space self-consistent field (MC-CASSCF) wave function approach as well as modelling the UV-vis absorption spectra with time-dependent density functional theory (TD-DFT). The MC-CASSCF calculations disclose a weak interaction between iron and the dioxygenic ligand and a dominant configuration with an essentially ferrous-superoxo character. The computed UV-vis absorption spectra reveal a marked dependence on the choice of density functional - both in terms of location of bands and in terms of orbital contributors. For the main band in the visible region, besides the recently reported thiolate-to-superoxide charge transfer, a more salient, and less functional-dependent, feature is a thiolate-to-ferric iron charge transfer, consistent with a ferric-peroxo electromer. By contrast, the computed UV-vis spectra of a ferric-hydroperoxo SOR model match distinctly better (and with no qualitative dependence on the DFT methodology) the 600-nm band as due to a mainly thiolate-to-ferric character - supporting the assignment of the SOR "600-nm intermediate" as a S=5/2 ferric-hydroperoxo species.
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Affiliation(s)
- Amr A A Attia
- Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Daniela Cioloboc
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, United States
| | - Alexandru Lupan
- Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Radu Silaghi-Dumitrescu
- Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania.
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7
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Horch M, Utesch T, Hildebrandt P, Mroginski MA, Zebger I. Domain motions and electron transfer dynamics in 2Fe-superoxide reductase. Phys Chem Chem Phys 2016; 18:23053-66. [DOI: 10.1039/c6cp03666j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Theoretical studies on 2Fe-superoxide reductase provide mechanistic insights into structural dynamics and electron transfer efficiencies.
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Affiliation(s)
- Marius Horch
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Tillmann Utesch
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Peter Hildebrandt
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | | | - Ingo Zebger
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
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8
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Pinto AF, Romão CV, Pinto LC, Huber H, Saraiva LM, Todorovic S, Cabelli D, Teixeira M. Superoxide reduction by a superoxide reductase lacking the highly conserved lysine residue. J Biol Inorg Chem 2015; 20:155-164. [PMID: 25476860 DOI: 10.1007/s00775-014-1222-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 11/26/2014] [Indexed: 01/12/2023]
Abstract
Superoxide reductases (SORs) are the most recently identified superoxide detoxification systems, being found in microorganisms from the three domains of life. These enzymes are characterized by a catalytic mononuclear iron site, with one cysteine and four histidine ligands of the ferrous active form. A lysine residue in the -EKHVP- motif, located close to the active site, has been considered to be essential for the enzyme function, by contributing to the positive surface patch that attracts the superoxide anion and by controlling the chemistry of the catalytic mechanism through a hydrogen bond network. However, we show here that this residue is substituted by non-equivalent amino acids in several putative SORs from Archaea and unicellular Eukarya. In this work, we focus on mechanistic and spectroscopic studies of one of these less common enzymes, the SOR from the hyperthermophilic Crenarchaeon Ignicoccus hospitalis. We employ pulse radiolysis fast kinetics and spectroscopic approaches to study the wild-type enzyme (-E23T24HVP-), and two mutants, T24K and E23A, the later mimicking enzymes lacking both the lysine and glutamate (a ferric ion ligand) of the motif. The efficiency of the wild-type protein and mutants in reducing superoxide is comparable to other SORs, revealing the robustness of these enzymes to single mutations.
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Affiliation(s)
- Ana F Pinto
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, 17177, Stockholm, Sweden
| | - Célia V Romão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal
| | - Liliana C Pinto
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal
| | - Harald Huber
- Lehrstuhl fuer Mikrobiologie, Universität Regensburg, 93053, Regensburg, Germany
| | - Lígia M Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal
| | - Smilja Todorovic
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal
| | - Diane Cabelli
- Chemistry Department, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA
| | - Miguel Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Apartado 127, 2781-901, Oeiras, Portugal.
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9
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Sheng Y, Abreu IA, Cabelli DE, Maroney MJ, Miller AF, Teixeira M, Valentine JS. Superoxide dismutases and superoxide reductases. Chem Rev 2014; 114:3854-918. [PMID: 24684599 PMCID: PMC4317059 DOI: 10.1021/cr4005296] [Citation(s) in RCA: 600] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Yuewei Sheng
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
| | - Isabel A. Abreu
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
- Instituto
de Biologia Experimental e Tecnológica, Av. da República,
Qta. do Marquês, Estação Agronómica Nacional,
Edificio IBET/ITQB, 2780-157, Oeiras, Portugal
| | - Diane E. Cabelli
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Michael J. Maroney
- Department
of Chemistry, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Anne-Frances Miller
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Miguel Teixeira
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Joan Selverstone Valentine
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
- Department
of Bioinspired Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea
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10
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Rat S, Ménage S, Thomas F, Nivière V. Non-heme iron hydroperoxo species in superoxide reductase as a catalyst for oxidation reactions. Chem Commun (Camb) 2014; 50:14213-6. [DOI: 10.1039/c4cc06114d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The non-heme high-spin ferric iron hydroperoxo species formed in superoxide reductase can act both as a nucleophile and as an electrophile to catalyze oxidation reactions.
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Affiliation(s)
- S. Rat
- Univ. Grenoble Alpes
- iRTSV-LCBM
- F-38000 Grenoble, France
- CNRS
- iRTSV-LCBM
| | - S. Ménage
- Univ. Grenoble Alpes
- iRTSV-LCBM
- F-38000 Grenoble, France
- CNRS
- iRTSV-LCBM
| | - F. Thomas
- Département de Chimie Moléculaire – Chimie Inorganique Redox Biomimétique (CIRE) – UMR CNRS 5250
- Univ. Grenoble Alpes
- 38041 Grenoble cedex 9, France
| | - V. Nivière
- Univ. Grenoble Alpes
- iRTSV-LCBM
- F-38000 Grenoble, France
- CNRS
- iRTSV-LCBM
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11
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Horch M, Pinto AF, Utesch T, Mroginski MA, Romão CV, Teixeira M, Hildebrandt P, Zebger I. Reductive activation and structural rearrangement in superoxide reductase: a combined infrared spectroscopic and computational study. Phys Chem Chem Phys 2014; 16:14220-30. [DOI: 10.1039/c4cp00884g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Local and global structural changes that enable reductive activation of superoxide reductase are revealed by a combined approach of infrared difference spectroscopy and computational methods.
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Affiliation(s)
- M. Horch
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - A. F. Pinto
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - T. Utesch
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - M. A. Mroginski
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - C. V. Romão
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - M. Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - P. Hildebrandt
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - I. Zebger
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
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12
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Tremey E, Bonnot F, Moreau Y, Berthomieu C, Desbois A, Favaudon V, Blondin G, Houée-Levin C, Nivière V. Hydrogen bonding to the cysteine ligand of superoxide reductase: acid–base control of the reaction intermediates. J Biol Inorg Chem 2013; 18:815-30. [DOI: 10.1007/s00775-013-1025-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 07/15/2013] [Indexed: 12/26/2022]
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13
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Zanello P. The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part I. {Fe(SγCys)4} proteins. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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14
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Fe–O versus O–O bond cleavage in reactive iron peroxide intermediates of superoxide reductase. J Biol Inorg Chem 2012; 18:95-101. [DOI: 10.1007/s00775-012-0954-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
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15
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Bonnot F, Molle T, Ménage S, Moreau Y, Duval S, Favaudon V, Houée-Levin C, Nivière V. Control of the Evolution of Iron Peroxide Intermediate in Superoxide Reductase from Desulfoarculus baarsii. Involvement of Lysine 48 in Protonation. J Am Chem Soc 2012; 134:5120-30. [DOI: 10.1021/ja209297n] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Florence Bonnot
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
| | - Thibaut Molle
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
| | - Stéphane Ménage
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
| | - Yohann Moreau
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
| | - Simon Duval
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
| | - Vincent Favaudon
- Institut Curie, Inserm U612, Bâtiment 110-112,
Centre Universitaire 91405
Orsay Cedex, France
| | - Chantal Houée-Levin
- Laboratoire
de Chimie Physique,
UMR8000 CNRS/Université Paris-Sud, Bâtiment 350, Centre Universitaire 91405 Orsay Cedex, France
| | - Vincent Nivière
- CEA, iRTSV, Laboratoire de Chimie et Biologie des Métaux,
F-38054 Grenoble,
France
- Université de Grenoble, F-38000 Grenoble, France
- CNRS, UMR 5249, F-38054
Grenoble, France
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Lucchetti-Miganeh C, Goudenège D, Thybert D, Salbert G, Barloy-Hubler F. SORGOdb: Superoxide Reductase Gene Ontology curated DataBase. BMC Microbiol 2011; 11:105. [PMID: 21575179 PMCID: PMC3116461 DOI: 10.1186/1471-2180-11-105] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 05/16/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Superoxide reductases (SOR) catalyse the reduction of superoxide anions to hydrogen peroxide and are involved in the oxidative stress defences of anaerobic and facultative anaerobic organisms. Genes encoding SOR were discovered recently and suffer from annotation problems. These genes, named sor, are short and the transfer of annotations from previously characterized neelaredoxin, desulfoferrodoxin, superoxide reductase and rubredoxin oxidase has been heterogeneous. Consequently, many sor remain anonymous or mis-annotated. DESCRIPTION SORGOdb is an exhaustive database of SOR that proposes a new classification based on domain architecture. SORGOdb supplies a simple user-friendly web-based database for retrieving and exploring relevant information about the proposed SOR families. The database can be queried using an organism name, a locus tag or phylogenetic criteria, and also offers sequence similarity searches using BlastP. Genes encoding SOR have been re-annotated in all available genome sequences (prokaryotic and eukaryotic (complete and in draft) genomes, updated in May 2010). CONCLUSIONS SORGOdb contains 325 non-redundant and curated SOR, from 274 organisms. It proposes a new classification of SOR into seven different classes and allows biologists to explore and analyze sor in order to establish correlations between the class of SOR and organism phenotypes. SORGOdb is freely available at http://sorgo.genouest.org/index.php.
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Affiliation(s)
- Céline Lucchetti-Miganeh
- CNRS UMR 6026, ICM, Equipe Sp@rte, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France.
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Stasser J, Namuswe F, Kasper GD, Jiang Y, Krest CM, Green MT, Penner-Hahn J, Goldberg DP. X-ray absorption spectroscopy and reactivity of thiolate-ligated Fe(III)-OOR complexes. Inorg Chem 2011; 49:9178-90. [PMID: 20839847 DOI: 10.1021/ic100670k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of a series of thiolate-ligated iron(II) complexes [Fe(II)([15]aneN(4))(SC(6)H(5))]BF(4) (1), [Fe(II)([15]aneN(4))(SC(6)H(4)-p-Cl)]BF(4) (2), and [Fe(II)([15]aneN(4))(SC(6)H(4)-p-NO(2))]BF(4) (3) with alkylhydroperoxides at low temperature (-78 °C or -40 °C) leads to the metastable alkylperoxo-iron(III) species [Fe(III)([15]aneN(4))(SC(6)H(5))(OOtBu)]BF(4) (1a), [Fe(III)([15]aneN(4))(SC(6)H(4)-p-Cl)(OOtBu)]BF(4) (2a), and [Fe(III)([15]aneN(4))(SC(6)H(4)-p-NO(2))(OOtBu)]BF(4) (3a), respectively. X-ray absorption spectroscopy (XAS) studies were conducted on the Fe(III)-OOR complexes and their iron(II) precursors. The edge energy for the iron(II) complexes (∼7118 eV) shifts to higher energy upon oxidation by ROOH, and the resulting edge energies for the Fe(III)-OOR species range from 7121-7125 eV and correlate with the nature of the thiolate donor. Extended X-ray absorption fine structure (EXAFS) analysis of the iron(II) complexes 1-3 in CH(2)Cl(2) show that their solid state structures remain intact in solution. The EXAFS data on 1a-3a confirm their proposed structures as mononuclear, 6-coordinate Fe(III)-OOR complexes with 4N and 1S donors completing the coordination sphere. The Fe-O bond distances obtained from EXAFS for 1a-3a are 1.82-1.85 Å, significantly longer than other low-spin Fe(III)-OOR complexes. The Fe-O distances correlate with the nature of the thiolate donor, in agreement with the previous trends observed for ν(Fe-O) from resonance Raman (RR) spectroscopy, and supported by optimized geometries obtained from density functional theory (DFT) calculations. Reactivity and kinetic studies on 1a- 3a show an important influence of the thiolate donor.
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Affiliation(s)
- Jay Stasser
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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What causes iron-sulphur bonds in active sites of one-iron superoxide reductase and two-iron superoxide reductase to differ? CHEMICAL PAPERS 2011. [DOI: 10.2478/s11696-011-0023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AbstractThe electronic and vibrational properties of [Fe(NHis)4(SCys)] sites responsible for the catalysis of superoxide reduction in two types of superoxide reductase (SOR), one-iron superoxide reductase (1Fe-SOR) and two-iron superoxide reductase (2Fe-SOR), were compared previously (Clay et al., 2003); the differences between these two classes of SOR, examined by UV-VIS and NIR absorption, VTMCD, and vibrational spectroscopy techniques, were interpreted as being indicative of weaker Fe-S bonds in 2Fe-SOR in comparison with 1Fe-SOR. Here, we report on density functional (DFT) and semi-empirical (ZINDO/S-CI) calculations exploring the extent of this difference in bonding between the two classes of SOR. The differences observed experimentally between the electronic spectra of the two SORs are shown to probably arise either from different degrees of torsion between the Fe—ligand bonds or from differences in length of the Fe—carboxylate bond, but are shown to be incompatible with any significant differences in Fe—S bond lengths. The differences observed in the vibrational spectra between the two SORs are shown to correlate with differences in the Fe-S bond length of no more than 0.01 Å, which in turn arise from slight differences in the polarity of the medium surrounding the iron active site in the two proteins.
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Sit PHL, Migliore A, Ho MH, Klein ML. Quantum Mechanical and Quantum Mechanical/Molecular Mechanical Studies of the Iron−Dioxygen Intermediates and Proton Transfer in Superoxide Reductase. J Chem Theory Comput 2010; 6:2896-909. [DOI: 10.1021/ct900599q] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Patrick H.-L. Sit
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel, and Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19130
| | - Agostino Migliore
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel, and Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19130
| | - Ming-Hsun Ho
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel, and Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19130
| | - Michael L. Klein
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel, and Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19130
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20
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Namuswe F, Hayashi T, Jiang Y, Kasper GD, Sarjeant AAN, Moënne-Loccoz P, Goldberg DP. Influence of the nitrogen donors on nonheme iron models of superoxide reductase: high-spin Fe(III)-OOR complexes. J Am Chem Soc 2010; 132:157-67. [PMID: 20000711 DOI: 10.1021/ja904818z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new five-coordinate, (N(4)S(thiolate))Fe(II) complex, containing tertiary amine donors, [Fe(II)(Me(4)[15]aneN(4))(SPh)]BPh(4) (2), was synthesized and structurally characterized as a model of the reduced active site of superoxide reductase (SOR). Reaction of 2 with tert-butyl hydroperoxide (tBuOOH) at -78 degrees C led to the generation of the alkylperoxo-iron(III) complex [Fe(III)(Me(4)[15]aneN(4))(SPh)(OOtBu)](+) (2a). The nonthiolate-ligated complex, [Fe(II)(Me(4)[15]aneN(4))(OTf)(2)] (3), was also reacted with tBuOOH and yielded the corresponding alkylperoxo complex [Fe(III)(Me(4)[15]aneN(4))(OTf)(OOtBu)](+) (3a) at an elevated temperature of -23 degrees C. These species were characterized by low-temperature UV-vis, EPR, and resonance Raman spectroscopies. Complexes 2a and 3a exhibit distinctly different spectroscopic signatures than the analogous alkylperoxo complexes [Fe(III)([15]aneN(4))(SAr)(OOR)](+), which contain secondary amine donors. Importantly, alkylation at nitrogen leads to a change from low-spin (S = 1/2) to high-spin (S = 5/2) of the iron(III) center. The resonance Raman data reveal that this change in spin state has a large effect on the nu(Fe-O) and nu(O-O) vibrations, and a comparison between 2a and the nonthiolate-ligated complex 3a shows that axial ligation has an additional significant impact on these vibrations. To our knowledge this study is the first in which the influence of a ligand trans to a peroxo moiety has been evaluated for a structurally equivalent pair of high-spin/low-spin peroxo-iron(III) complexes. The implications of spin state and thiolate ligation are discussed with regard to the functioning of SOR.
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Affiliation(s)
- Frances Namuswe
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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21
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Bonnot F, Houée-Levin C, Favaudon V, Nivière V. Photochemical processes observed during the reaction of superoxide reductase from Desulfoarculus baarsii with superoxide: re-evaluation of the reaction mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1804:762-7. [PMID: 19962458 DOI: 10.1016/j.bbapap.2009.11.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 10/30/2009] [Accepted: 11/23/2009] [Indexed: 11/24/2022]
Abstract
Superoxide reductase SOR is an enzyme involved in superoxide detoxification in some microorganisms. Its active site consists of a non-heme ferrous center in an unusual [Fe(NHis)(4) (SCys)(1)] square pyramidal pentacoordination that efficiently reduces superoxide into hydrogen peroxide. In previous works, the reaction mechanism of the SOR from Desulfoarculus baarsii enzyme, studied by pulse radiolysis, was shown to involve the formation of two reaction intermediates T1 and T2. However, the absorption spectrum of T2 was reported with an unusual sharp band at 625 nm, very different from that reported for other SORs. In this work, we show that the sharp band at 625 nm observed by pulse radiolysis reflects the presence of photochemical processes that occurs at the level of the transient species formed during the reaction of SOR with superoxide. These processes do not change the stoichiometry of the global reaction. These data highlight remarkable photochemical properties for these reaction intermediates, not previously suspected for iron-peroxide species formed in the SOR active site. We have reinvestigated the reaction mechanism of the SOR from D. baarsii by pulse radiolysis in the absence of these photochemical processes. The T1 and T2 intermediates now appear to have absorption spectra similar to those reported for the Archaeoglobus fulgidus SOR enzymes. Although for some enzymes of the family only one transient was reported, on the whole, the reaction mechanisms of the different SORs studied so far seem very similar, which is in agreement with the strong sequence and structure homologies of their active sites.
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Affiliation(s)
- Florence Bonnot
- Laboratoire de Chimie et Biologie des Métaux, CEA iRTSV, CNRS, Université Joseph Fourier, UMR 5249, 38054 Grenoble Cedex 9, France
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22
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Pinto AF, Rodrigues JV, Teixeira M. Reductive elimination of superoxide: Structure and mechanism of superoxide reductases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1804:285-97. [PMID: 19857607 DOI: 10.1016/j.bbapap.2009.10.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 10/12/2009] [Accepted: 10/14/2009] [Indexed: 10/20/2022]
Abstract
Superoxide anion is among the deleterious reactive oxygen species, towards which all organisms have specialized detoxifying enzymes. For quite a long time, superoxide elimination was thought to occur through its dismutation, catalyzed by Fe, Cu, and Mn or, as more recently discovered, by Ni-containing enzymes. However, during the last decade, a novel type of enzyme was established that eliminates superoxide through its reduction: the superoxide reductases, which are spread among anaerobic and facultative microorganisms, from the three life kingdoms. These enzymes share the same unique catalytic site, an iron ion bound to four histidines and a cysteine that, in its reduced form, reacts with superoxide anion with a diffusion-limited second order rate constant of approximately 10(9) M(-1) s(-1). In this review, the properties of these enzymes will be thoroughly discussed.
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Affiliation(s)
- Ana Filipa Pinto
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
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23
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Superoxide interaction with nickel and iron superoxide dismutases. J Mol Graph Model 2009; 28:156-61. [DOI: 10.1016/j.jmgm.2009.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 06/09/2009] [Accepted: 06/10/2009] [Indexed: 11/22/2022]
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24
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Todorovic S, Rodrigues JV, Pinto AF, Thomsen C, Hildebrandt P, Teixeira M, Murgida DH. Resonance Raman study of the superoxide reductase from Archaeoglobus fulgidus, E12 mutants and a ‘natural variant’. Phys Chem Chem Phys 2009; 11:1809-15. [DOI: 10.1039/b815489a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Rodrigues JV, Victor BL, Huber H, Saraiva LM, Soares CM, Cabelli DE, Teixeira M. Superoxide reduction by Nanoarchaeum equitans neelaredoxin, an enzyme lacking the highly conserved glutamate iron ligand. J Biol Inorg Chem 2007; 13:219-28. [PMID: 17968598 DOI: 10.1007/s00775-007-0313-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 10/15/2007] [Indexed: 10/22/2022]
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26
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Kitagawa T, Dey A, Lugo-Mas P, Benedict JB, Kaminsky W, Solomon E, Kovacs JA. A functional model for the cysteinate-ligated non-heme iron enzyme superoxide reductase (SOR). J Am Chem Soc 2007; 128:14448-9. [PMID: 17090014 PMCID: PMC2532059 DOI: 10.1021/ja064870d] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Superoxide reductases (SORs) are cysteine-ligated, non-heme iron enzymes that reduce toxic superoxide radicals (O2-). The functional role of the trans cysteinate, as well as the mechanism by which SOR reduces O2-, is unknown. Herein is described a rare example of a functional metalloenzyme analogue, which catalytically reduces superoxide in a proton-dependent mechanism, via a trans thiolate-ligated iron-peroxo intermediate, the first example of its type. Acetic-acid-promoted H2O2 release, followed by Cp2Co reduction, regenerates the active Fe(II) catalyst. The thiolate ligand and its trans positioning relative to the substrate are shown to contribute significantly to the catalyst's function, by lowering the redox potential, changing the spin state, and dramatically lowering the nuFe-O stretching frequency well-below that of any other reported iron-peroxo, while leaving nuO-O high, so as to favor superoxide reduction and Fe-O, as opposed to O-O, bond cleavage. Thus we provide critical insight into the relationship between the SOR structure and its function, as well as important benchmark parameters for characterizing highly unstable thiolate-ligated iron-peroxo intermediates.
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27
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Pereira AS, Tavares P, Folgosa F, Almeida RM, Moura I, Moura JJG. Superoxide Reductases. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Alice S. Pereira
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Pedro Tavares
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Filipe Folgosa
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Rui M. Almeida
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Isabel Moura
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - José J. G. Moura
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
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Mathé C, Weill CO, Mattioli TA, Berthomieu C, Houée-Levin C, Tremey E, Nivière V. Assessing the role of the active-site cysteine ligand in the superoxide reductase from Desulfoarculus baarsii. J Biol Chem 2007; 282:22207-16. [PMID: 17545670 DOI: 10.1074/jbc.m700279200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Superoxide reductase is a novel class of non-heme iron proteins that catalyzes the one-electron reduction of O(2)(.) to H(2)O(2), providing an antioxidant defense in some bacteria. Its active site consists of an unusual non-heme Fe(2+) center in a [His(4) Cys(1)] square pyramidal pentacoordination. In this class of enzyme, the cysteine axial ligand has been hypothesized to be an essential feature in the reactivity of the enzyme. Previous Fourier transform infrared spectroscopy studies on the enzyme from Desulfoarculus baarsii revealed that a protonated carboxylate group, proposed to be the side chain of Glu(114), is in interaction with the cysteine ligand. In this work, using pulse radiolysis, Fourier transform infrared, and resonance Raman spectroscopies, we have investigated to what extent the presence of this Glu(114) carboxylic lateral chain affects the strength of the S-Fe bond and the reaction of the iron active site with superoxide. The E114A mutant shows significantly modified pulse radiolysis kinetics for the protonation process of the first reaction intermediate. Resonance Raman spectroscopy demonstrates that the E114A mutation results in both a strengthening of the S-Fe bond and an increase in the extent of freeze-trapping of a Fe-peroxo species after treatment with H(2)O(2) by a specific strengthening of the Fe-O bond. A fine tuning of the strength of the S-Fe bond by the presence of Glu(114) appears to be an essential factor for both the strength of the Fe-O bond and the pK(a) value of the Fe(3+)-peroxo intermediate species to form the reaction product H(2)O(2).
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Affiliation(s)
- Christelle Mathé
- Laboratoire de Chimie et Biologie des Métaux, iRTSV-CEA Grenoble/CNRS/Université Joseph Fourier, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9, France
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Katona G, Carpentier P, Nivière V, Amara P, Adam V, Ohana J, Tsanov N, Bourgeois D. Raman-assisted crystallography reveals end-on peroxide intermediates in a nonheme iron enzyme. Science 2007; 316:449-53. [PMID: 17446401 DOI: 10.1126/science.1138885] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Iron-peroxide intermediates are central in the reaction cycle of many iron-containing biomolecules. We trapped iron(III)-(hydro)peroxo species in crystals of superoxide reductase (SOR), a nonheme mononuclear iron enzyme that scavenges superoxide radicals. X-ray diffraction data at 1.95 angstrom resolution and Raman spectra recorded in crystallo revealed iron-(hydro)peroxo intermediates with the (hydro)peroxo group bound end-on. The dynamic SOR active site promotes the formation of transient hydrogen bond networks, which presumably assist the cleavage of the iron-oxygen bond in order to release the reaction product, hydrogen peroxide.
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Affiliation(s)
- Gergely Katona
- Institut de Biologie Structurale (IBS) Jean-Pierre Ebel, Commissariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier, 41 rue Jules Horowitz, F-38027 Grenoble, France
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30
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Brines LM, Kovacs JA. Understanding the Mechanism of Superoxide Reductase Promoted Reduction of Superoxide. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600461] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lisa M. Brines
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, USA, Fax: +1‐206‐685‐8665
| | - Julie A. Kovacs
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, USA, Fax: +1‐206‐685‐8665
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31
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Krishnamurthy D, Kasper GD, Namuswe F, Kerber WD, Narducci Sarjeant AA, Moënne-Loccoz P, Goldberg DP. A Low-Spin Alkylperoxo−Iron(III) Complex with Weak Fe−O and O−O Bonds: Implications for the Mechanism of Superoxide Reductase. J Am Chem Soc 2006; 128:14222-3. [PMID: 17076472 DOI: 10.1021/ja064525o] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of a mononuclear, five-coordinate ferrous complex [([15]aneN4)FeII(SPh)](BF4) (1) is reported. This complex is a new model of the reduced active site of the enzyme superoxide reductase (SOR), which is comprised of a [(NHis)4(Scys)FeII] center. Complex 1 reacts with alkylhydroperoxides (tBuOOH, cumenylOOH) at low temperature to give a metastable, dark red intermediate (2a: R = tBu; 2b: R = cumenyl) that has been characterized by UV-vis, EPR, and resonance Raman spectroscopy. The UV-vis spectrum (-80 degrees C) reveals a 526 nm absorbance (epsilon = 2150 M-1 cm-1) for 2a and a 527 nm absorbance (epsilon = 1650 M-1 cm-1) for 2b, indicative of alkylperoxo-to-iron(III) LMCT transitions, and the EPR data (77 K) show that both intermediates are low-spin iron(III) complexes (g = 2.20 and 1.97). Definitive identification of the Fe(III)-OOR species comes from RR spectra, which give nu(Fe-O) = 612 (2a) and 615 (2b) cm-1, and nu(O-O) = 803 (2a) and 795 (2b) cm-1. The assignments for 2a were confirmed by 18O substitution (tBu18O18OH), resulting in a 28 cm-1 downshift for nu(Fe-18O), and a 46 cm-1 downshift for nu(18O-18O). These data show that 2a and 2b are low-spin FeIII-OOR species with weak Fe-O bonds and suggest that a low-spin intermediate may occur in SOR, as opposed to previous proposals invoking high-spin intermediates.
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Affiliation(s)
- Divya Krishnamurthy
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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32
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Rodrigues JV, Abreu IA, Cabelli D, Teixeira M. Superoxide reduction mechanism of Archaeoglobus fulgidus one-iron superoxide reductase. Biochemistry 2006; 45:9266-78. [PMID: 16866373 DOI: 10.1021/bi052489k] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Superoxide reductases (SORs), iron-centered enzymes responsible for reducing superoxide (O2(-)) to hydrogen peroxide, are found in many anaerobic and microaerophilic prokaryotes. The rapid reaction with an exogenous electron donor renders the reductase activity catalytic. Here, we demonstrate using pulse radiolysis that the initial reaction between O2(-) and Archaeoglobus fulgidus neelaredoxin, a one-iron SOR, leads to a short-lived transient that immediately disappears to yield a solvent-bound ferric species in acid-base equilibrium. Through comparison of wild-type neelaredoxin with mutants lacking the ferric ion coordinating glutamate, we demonstrate that the remaining step is related to the final coordination of this ligand to the oxidized metal center and kinetically characterize it for the first time, by pulse radiolysis and stopped-flow kinetics. The way exogenous phosphate perturbs the kinetics of superoxide reduction by neelaredoxin and mutant proteins was also investigated.
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Affiliation(s)
- João V Rodrigues
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2784-505 Oeiras, Portugal
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