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Abou-Hamdan A, Mahler R, Grossenbacher P, Biner O, Sjöstrand D, Lochner M, Högbom M, von Ballmoos C. Functional design of bacterial superoxide:quinone oxidoreductase. Biochim Biophys Acta Bioenerg 2022; 1863:148583. [PMID: 35671795 DOI: 10.1016/j.bbabio.2022.148583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/10/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
The superoxide anion - molecular oxygen reduced by a single electron - is produced in large amounts by enzymatic and adventitious reactions. It can perform a range of cellular functions, including bacterial warfare and iron uptake, signalling and host immune response in eukaryotes. However, it also serves as precursor for more deleterious species such as the hydroxyl anion or peroxynitrite and defense mechanisms to neutralize superoxide are important for cellular health. In addition to the soluble proteins superoxide dismutase and superoxide reductase, recently the membrane embedded diheme cytochrome b561 (CybB) from E. coli has been proposed to act as a superoxide:quinone oxidoreductase. Here, we confirm superoxide and cellular ubiquinones or menaquinones as natural substrates and show that quinone binding to the enzyme accelerates the reaction with superoxide. The reactivity of the substrates is in accordance with the here determined midpoint potentials of the two b hemes (+48 and -23 mV / NHE). Our data suggest that the enzyme can work near the diffusion limit in the forward direction and can also catalyse the reverse reaction efficiently under physiological conditions. The data is discussed in the context of described cytochrome b561 proteins and potential physiological roles of CybB.
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Affiliation(s)
- Abbas Abou-Hamdan
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Roman Mahler
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Philipp Grossenbacher
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012 Bern, Switzerland
| | - Olivier Biner
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland; Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Dan Sjöstrand
- Stockholm center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Martin Lochner
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012 Bern, Switzerland
| | - Martin Högbom
- Stockholm center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Christoph von Ballmoos
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.
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2
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Angius F, Ilioaia O, Amrani A, Suisse A, Rosset L, Legrand A, Abou-Hamdan A, Uzan M, Zito F, Miroux B. A novel regulation mechanism of the T7 RNA polymerase based expression system improves overproduction and folding of membrane proteins. Sci Rep 2018; 8:8572. [PMID: 29872064 PMCID: PMC5988807 DOI: 10.1038/s41598-018-26668-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 05/04/2018] [Indexed: 02/03/2023] Open
Abstract
Membrane protein (MP) overproduction is one of the major bottlenecks in structural genomics and biotechnology. Despite the emergence of eukaryotic expression systems, bacteria remain a cost effective and powerful tool for protein production. The T7 RNA polymerase (T7RNAP)-based expression system is a successful and efficient expression system, which achieves high-level production of proteins. However some foreign MPs require a fine-tuning of their expression to minimize the toxicity associated with their production. Here we report a novel regulation mechanism for the T7 expression system. We have isolated two bacterial hosts, namely C44(DE3) and C45(DE3), harboring a stop codon in the T7RNAP gene, whose translation is under the control of the basal nonsense suppressive activity of the BL21(DE3) host. Evaluation of hosts with superfolder green fluorescent protein (sfGFP) revealed an unprecedented tighter control of transgene expression with a marked accumulation of the recombinant protein during stationary phase. Analysis of a collection of twenty MP fused to GFP showed an improved production yield and quality of several bacterial MPs and of one human monotopic MP. These mutant hosts are complementary to the other existing T7 hosts and will increase the versatility of the T7 expression system.
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Affiliation(s)
- Federica Angius
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Oana Ilioaia
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Amira Amrani
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Annabelle Suisse
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France.,Helen L. and Martin S. Kimmel Center at the Skirball Institute for Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, New York, USA
| | - Lindsay Rosset
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Amélie Legrand
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Abbas Abou-Hamdan
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France.,Institut de Biologie Intégrative de la Cellule, CNRS, Gif sur Yvette, France
| | - Marc Uzan
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Francesca Zito
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Bruno Miroux
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France.
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3
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Abou-Hamdan A, Belot L, Albertini A, Gaudin Y. Monomeric Intermediates Formed by Vesiculovirus Glycoprotein during Its Low-pH-induced Structural Transition. J Mol Biol 2018; 430:1685-1695. [PMID: 29678555 PMCID: PMC7126088 DOI: 10.1016/j.jmb.2018.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/06/2018] [Accepted: 04/10/2018] [Indexed: 01/26/2023]
Abstract
Vesiculovirus G is the prototype of class III viral fusion glycoproteins. The structures of both G pre- and post-fusion conformation have been determined. The structure of monomeric intermediates reveals the pathway of the transition. A fusion-loop-exposing antiparallel dimer may initiate the fusion process. Those data challenge the current model proposed for viral membrane fusion.
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Affiliation(s)
- Abbas Abou-Hamdan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Laura Belot
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Aurélie Albertini
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Yves Gaudin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France.
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4
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Baquero E, Albertini AA, Raux H, Abou-Hamdan A, Boeri-Erba E, Ouldali M, Buonocore L, Rose JK, Lepault J, Bressanelli S, Gaudin Y. Structural intermediates in the fusion-associated transition of vesiculovirus glycoprotein. EMBO J 2017; 36:679-692. [PMID: 28188244 DOI: 10.15252/embj.201694565] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 11/09/2022] Open
Abstract
Vesiculoviruses enter cells by membrane fusion, driven by a large, low-pH-induced, conformational change in the fusion glycoprotein G that involves transition from a trimeric pre-fusion toward a trimeric post-fusion state via monomeric intermediates. Here, we present the structure of the G fusion protein at intermediate pH for two vesiculoviruses, vesicular stomatitis virus (VSV) and Chandipura virus (CHAV), which is responsible for deadly encephalopathies. First, a CHAV G crystal structure shows two intermediate conformations forming a flat dimer of heterodimers. On virions, electron microscopy (EM) and tomography reveal monomeric spikes similar to one of the crystal conformations. In solution, mass spectrometry shows dimers of G. Finally, mutations at a dimer interface, involving fusion domains associated in an antiparallel manner to form an intermolecular β-sheet, affect G fusion properties. The location of the compensatory mutations restoring fusion activity strongly suggests that this interface is functionally relevant. This work reveals the range of G structural changes and suggests that G monomers can re-associate, through antiparallel interactions between fusion domains, into dimers that play a role at some early stage of the fusion process.
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Affiliation(s)
- Eduard Baquero
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Aurélie A Albertini
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Hélène Raux
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Abbas Abou-Hamdan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Elisabetta Boeri-Erba
- CNRS, CEA, Institut de Biologie Structurale (IBS), Université Grenoble Alpes, Grenoble, France
| | - Malika Ouldali
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | | | - John K Rose
- Yale University School of Medicine, New Haven, CT, USA
| | - Jean Lepault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Stéphane Bressanelli
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Yves Gaudin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
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5
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Abou-Hamdan A, Ransy C, Roger T, Guedouari-Bounihi H, Galardon E, Bouillaud F. Positive feedback during sulfide oxidation fine-tunes cellular affinity for oxygen. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2016; 1857:1464-1472. [DOI: 10.1016/j.bbabio.2016.04.282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 03/29/2016] [Accepted: 04/28/2016] [Indexed: 10/21/2022]
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6
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Abou-Hamdan A, Helmy N, Bounihi H, Prip-Buus C, Lenoir V, Lombès A, Bouillaud F. Mitochondria and sulfide. Nitric Oxide 2015. [DOI: 10.1016/j.niox.2015.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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7
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Abou-Hamdan A, Ceccaldi P, Lebrette H, Gutiérrez-Sanz O, Richaud P, Cournac L, Guigliarelli B, De Lacey AL, Léger C, Volbeda A, Burlat B, Dementin S. A threonine stabilizes the NiC and NiR catalytic intermediates of [NiFe]-hydrogenase. J Biol Chem 2015; 290:8550-8. [PMID: 25666617 DOI: 10.1074/jbc.m114.630491] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The heterodimeric [NiFe] hydrogenase from Desulfovibrio fructosovorans catalyzes the reversible oxidation of H2 into protons and electrons. The catalytic intermediates have been attributed to forms of the active site (NiSI, NiR, and NiC) detected using spectroscopic methods under potentiometric but non-catalytic conditions. Here, we produced variants by replacing the conserved Thr-18 residue in the small subunit with Ser, Val, Gln, Gly, or Asp, and we analyzed the effects of these mutations on the kinetic (H2 oxidation, H2 production, and H/D exchange), spectroscopic (IR, EPR), and structural properties of the enzyme. The mutations disrupt the H-bond network in the crystals and have a strong effect on H2 oxidation and H2 production turnover rates. However, the absence of correlation between activity and rate of H/D exchange in the series of variants suggests that the alcoholic group of Thr-18 is not necessarily a proton relay. Instead, the correlation between H2 oxidation and production activity and the detection of the NiC species in reduced samples confirms that NiC is a catalytic intermediate and suggests that Thr-18 is important to stabilize the local protein structure of the active site ensuring fast NiSI-NiC-NiR interconversions during H2 oxidation/production.
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Affiliation(s)
- Abbas Abou-Hamdan
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Pierre Ceccaldi
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Hugo Lebrette
- Metalloproteins Unit, Institut de Biologie Structurale, UMR 5075 Commissariat à l'Energie Atomique/CNRS/Université Joseph Fourier, 6 rue Jules Horowitz, 38000, Grenoble, France
| | - Oscar Gutiérrez-Sanz
- Instituto de Catálisis y Petroleoquímica, Consejo Superior de Investigaciones Científicas, c/Marie Curie 2, L10, 28049 Madrid, Spain
| | - Pierre Richaud
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Saint-Paul-lez-Durance, F-13108, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale (BVME), Saint-Paul-lez-Durance, 13108, France, and Aix-Marseille Université, BVME UMR7265, Marseille F-13284, France
| | - Laurent Cournac
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Saint-Paul-lez-Durance, F-13108, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale (BVME), Saint-Paul-lez-Durance, 13108, France, and Aix-Marseille Université, BVME UMR7265, Marseille F-13284, France
| | - Bruno Guigliarelli
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Antonio L De Lacey
- Instituto de Catálisis y Petroleoquímica, Consejo Superior de Investigaciones Científicas, c/Marie Curie 2, L10, 28049 Madrid, Spain
| | - Christophe Léger
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Anne Volbeda
- Metalloproteins Unit, Institut de Biologie Structurale, UMR 5075 Commissariat à l'Energie Atomique/CNRS/Université Joseph Fourier, 6 rue Jules Horowitz, 38000, Grenoble, France
| | - Bénédicte Burlat
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Sébastien Dementin
- From the Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, UMR 7281 Aix-Marseille Université/CNRS, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France,
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Abstract
Hydrogen sulfide (H2S) is the third gasotransmitter described in mammals. These gasotransmitters (H2S, CO, and NO) are small molecules able to diffuse freely across membranes and thus susceptible to reach easily intracellular targets, one of which is the respiratory enzyme cytochrome oxidase subject to complete inhibition by low micromolar concentrations of these gases. However in contrast to NO or CO, H2S can be metabolized by a sulfide quinone reductase feeding the mitochondrial respiratory chain with the hydrogen atoms of sulfide. Sulfide is thus a two-sided molecule: substrate or poison according to the concentration. The aim of this chapter is to present a mean to monitor sulfide oxidation by isolated mitochondria or cells and to summarize how the properties of this amazing couple (mitochondria and sulfide) translate into practical and conceptual consequences.
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Affiliation(s)
- Abbas Abou-Hamdan
- Inserm U1016, Institut Cochin, Paris, France; CNRS UM8104, Institut Cochin, Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, Paris, France
| | - Hala Guedouari-Bounihi
- Inserm U1016, Institut Cochin, Paris, France; CNRS UM8104, Institut Cochin, Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, Paris, France
| | - Véronique Lenoir
- Inserm U1016, Institut Cochin, Paris, France; CNRS UM8104, Institut Cochin, Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, Paris, France
| | - Mireille Andriamihaja
- INRA-CRNH-IdF-AgroParisTech, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - François Blachier
- INRA-CRNH-IdF-AgroParisTech, UMR 914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Frédéric Bouillaud
- Inserm U1016, Institut Cochin, Paris, France; CNRS UM8104, Institut Cochin, Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, Paris, France.
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9
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Helmy N, Prip-Buus C, Vons C, Lenoir V, Abou-Hamdan A, Guedouari-Bounihi H, Lombès A, Bouillaud F. Oxidation of hydrogen sulfide by human liver mitochondria. Nitric Oxide 2014; 41:105-12. [PMID: 24928562 DOI: 10.1016/j.niox.2014.05.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 05/26/2014] [Accepted: 05/30/2014] [Indexed: 11/19/2022]
Abstract
Hydrogen sulfide (H2S) is the third gasotransmitter discovered. Sulfide shares with the two others (NO and CO) the same inhibiting properties towards mitochondrial respiration. However, in contrast with NO or CO, sulfide at concentrations lower than the toxic (μM) level is an hydrogen donor and a substrate for mitochondrial respiration. This is due to the activity of a sulfide quinone reductase found in a large majority of mitochondria. An ongoing study of the metabolic state of liver in obese patients allowed us to evaluate the sulfide oxidation capacity with twelve preparations of human liver mitochondria. The results indicate relatively high rates of sulfide oxidation with a large variability between individuals. These observations made with isolated mitochondria appear in agreement with the main characteristics of sulfide oxidation as established before with the help of cellular models.
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Affiliation(s)
- Nada Helmy
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France; Service de chirurgie digestive et métabolique, APHP, Hôpitaux universitaires de Seine Saint Denis Hôpital Jean Verdier, 93143 Bondy Cedex, France; Université Paris 13, Bobigny, France
| | - Carina Prip-Buus
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France
| | - Corinne Vons
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France; Service de chirurgie digestive et métabolique, APHP, Hôpitaux universitaires de Seine Saint Denis Hôpital Jean Verdier, 93143 Bondy Cedex, France; Université Paris 13, Bobigny, France
| | - Véronique Lenoir
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France
| | - Abbas Abou-Hamdan
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France
| | - Hala Guedouari-Bounihi
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France
| | - Anne Lombès
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France
| | - Frédéric Bouillaud
- Inserm U1016, Institut Cochin, 75014 Paris, France; CNRS UMR8104, Institut Cochin, 75014 Paris, France; Université Paris Descartes UMR-S1016, Institut Cochin, 75014 Paris, France.
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10
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Bouillaud F, Andriamihaja M, Mimoun S, Helmy N, Bounihi H, Abou-Hamdan A, Vons C, Prip-Buus C, Blachier F. S6-2 Mitochondrial oxidation of H2S in mammals. Nitric Oxide 2014. [DOI: 10.1016/j.niox.2014.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Fourmond V, Baffert C, Sybirna K, Dementin S, Abou-Hamdan A, Meynial-Salles I, Soucaille P, Bottin H, Léger C. The mechanism of inhibition by H2 of H2-evolution by hydrogenases. Chem Commun (Camb) 2013; 49:6840-2. [PMID: 23792933 DOI: 10.1039/c3cc43297a] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By analysing the results of experiments carried out with two FeFe hydrogenases and several "channel mutants" of a NiFe hydrogenase, we demonstrate that whether or not hydrogen evolution is significantly inhibited by H2 is not a consequence of active site chemistry, but rather relates to H2 transport within the enzyme.
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Affiliation(s)
- Vincent Fourmond
- CNRS, Aix-Marseille Université, BIP UMR 7281, 13009, Marseille, France
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12
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Saudan C, Dunand FA, Abou-Hamdan A, Bugnon P, Lye PG, Lincoln SF, Merbach AE. A model for sequential threading of alpha-cyclodextrin onto a guest: a complete thermodynamic and kinetic study in water. J Am Chem Soc 2001; 123:10290-8. [PMID: 11603979 DOI: 10.1021/ja010946o] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first variable-temperature and variable-pressure stopped-flow spectrophotometric study of the sequential threading of alpha-cyclodextrin (alpha-CD) onto the guest dye Mordant Orange 10, S, is reported. Complementary (1)H one-dimensional (1D) variable-temperature kinetic studies and two-dimensional (2D) rotating-frame nuclear Overhauser effect spectroscopy (ROESY) and EXSY NMR studies are also reported. In aqueous solution at 298.2 K, the first alpha-CD threads onto S to form a 1:1 complex S.alpha-CD with a forward rate constant k(1,f) = 15 200 +/- 200 M(-1) s(-1) and dethreads with a reverse rate constant k(1,r) = 4.4 +/- 0.3 s(-1). Subsequently, S.alpha-CD isomerizes to S.alpha-CD (k(3,f) = 0.158 +/- 0.006 s(-1), k(3,f) = 0.148 +/- 0.006 s(-1)). This process can be viewed as a thermodynamically controlled molecular shuttle. A second alpha-CD threads onto S.alpha-CD to form a 1:2 complex, S.(alpha-CD)(2), with k(2,f) = 98 +/- 2 M(-1) s(-1) and k(2,r) = 0.032 +/- 0.002 s(-1). A second alpha-CD also threads onto S.alpha-CD to form another 1:2 complex, S.(alpha-CD)(2), characterized by k(4,f) = 9640 +/- 1800 M(-1) s(-1) and k(4,r) = 61 +/- 6 s(-1). Direct interconvertion between S.(alpha-CD)(2) and S.(alpha-CD)(2) was not detected; instead, they interconvert by dethreading the second alpha-CD and through the isomerization equilibrium between S.alpha-CD and S.alpha-CD. The reaction volumes, DeltaV(0), were found to be negative for the first three equilibria and positive for the fourth equilibrium. For the first three forward and reverse reactions, the volumes of activation are substantially more negative, indicating a compression of the transition state in comparison with the ground states. These data were used in conjunction with DeltaH, DeltaH degrees, DeltaS, and DeltaS degrees data to deduce the dominant mechanistic threading processes, which appear to be largely controlled by changes in hydration and van der Waals interactions, and possibly by conformational changes in both S and alpha-CD. The structure of the four complexes were deduced from (1)H 2D ROESY NMR studies.
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Affiliation(s)
- C Saudan
- Institut de Chimie Minérale et Analytique, Université de Lausanne, CH-1015 Lausanne, Switzerland
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