Catalytic intermediates of cytochrome bd terminal oxidase at steady-state: Ferryl and oxy-ferrous species dominate
| Autor: | Alessandro Giuffrè, Paolo Sarti, Elena Forte, Vitaliy B. Borisov |
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| Přispěvatelé: | Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University - MSU (RUSSIA), Department of Biochemical Sciences, Università degli Studi di Roma 'La Sapienza' [Rome] - Réseau International des Instituts Pasteur - Institut Pasteur - Fondation Cenci Bolognetti, CNR - National Research Council of Italy, Institute of Molecular Biology and Pathology, This work was supported by the Russian Foundationfor Basic Research (to V.B.B.) and by the Ministero dell'Università edella Ricerca of Italy (PRIN 2008FJJHKM_002 to P.S. and FIRBRBFR08F41U_001 to A.G.), Lomonosov Moscow State University (MSU), Department of Biochemical Sciences 'Rossi Fanelli', Institut Pasteur, Fondation Cenci Bolognetti - Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Cytochrome
cytochrome bd ferrous uncomplexed heme d Ubiquinol oxidase MESH: Escherichia coli Proteins Photochemistry Biochemistry Cytochrome C1 3-dimethoxy-5- methyl-6-(3-methyl-2-butenyl)-1 4-benzoquinone catalytic turnover chlorin cyt bd dithiothreitol dtt f ferric heme d ferryl heme d hemoprotein o oxy oxy-ferrous heme d oxygen chemistry p peroxy heme d q1 r reaction mechanism respiration MESH: Cytochromes 0303 health sciences biology Cytochrome c peroxidase Chemistry MESH: Escherichia coli Cytochrome c Escherichia coli Proteins Cytochrome P450 reductase MESH: Ferrous Compounds Oxidoreductases MESH: Biocatalysis MESH: Electron Transport Chain Complex Proteins Hemeprotein Stereochemistry Biophysics Electron Transport Complex IV 03 medical and health sciences MESH: Electron Transport Complex IV Escherichia coli [SDV.BBM] Life Sciences [q-bio]/Biochemistry Molecular Biology Cytochrome c oxidase [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Ferrous Compounds MESH: Oxidoreductases 030304 developmental biology 030306 microbiology Cell Biology Cytochrome b Group Electron Transport Chain Complex Proteins biology.protein Biocatalysis Cytochromes |
| Zdroj: | Biochimica et Biophysica Acta (BBA)-Enzymology Biochimica et Biophysica Acta (BBA)-Enzymology, Elsevier, 2011, 1807 (5), pp.503-9. <10.1016/j.bbabio.2011.02.007> Biochimica et Biophysica Acta (BBA)-Enzymology, Elsevier, 2011, 1807 (5), pp.503-9. ⟨10.1016/j.bbabio.2011.02.007⟩ |
| ISSN: | 0005-2744 |
| DOI: | 10.1016/j.bbabio.2011.02.007> |
| Popis: | International audience; The cytochrome bd ubiquinol oxidase from Escherichia coli couples the exergonic two-electron oxidation of ubiquinol and four-electron reduction of O(2) to 2H(2)O to proton motive force generation by transmembrane charge separation. The oxidase contains two b-type hemes (b(558) and b(595)) and one heme d, where O(2) is captured and converted to water through sequential formation of a few intermediates. The spectral features of the isolated cytochrome bd at steady-state have been examined by stopped-flow multiwavelength absorption spectroscopy. Under turnover conditions, sustained by O(2) and dithiothreitol (DTT)-reduced ubiquinone, the ferryl and oxy-ferrous species are the mostly populated catalytic intermediates, with a residual minor fraction of the enzyme containing ferric heme d and possibly one electron on heme b(558). These findings are unprecedented and differ from those obtained with mammalian cytochrome c oxidase, in which the oxygen intermediates were not found to be populated at detectable levels under similar conditions [M.G. Mason, P. Nicholls, C.E. Cooper, The steady-state mechanism of cytochrome c oxidase: redox interactions between metal centres, Biochem. J. 422 (2009) 237-246]. The data on cytochrome bd are consistent with the observation that the purified enzyme has the heme d mainly in stable oxy-ferrous and ferryl states. The results are here discussed in the light of previously proposed models of the catalytic cycle of cytochrome bd. |
| Databáze: | OpenAIRE |
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