Bacterial respiratory chain diversity reveals a cytochrome c oxidase reducing O2 at low overpotentials
| Autor: | Magali Roger, Marielle Bauzan, Marianne Ilbert, Romain Clement, Ievgen Mazurenko, Elisabeth Lojou, Anne de Poulpiquet, Xie Wang |
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| Přispěvatelé: | Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), School of Natural and Environmental Sciences, Newcastle University [Newcastle], Institut de Microbiologie de la Méditerranée (IMM), ANR-16-CE05-0024,Enzymor,Bases moléculaires de l'immobilisation fonctionnelle d'enzymes pour des biopiles performantes(2016) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Kinetics
enzymes Respiratory chain macromolecular substances 010402 general chemistry Electrochemistry 01 natural sciences Biochemistry Redox Catalysis Electron transfer Colloid and Surface Chemistry cytochrome c oxidase Cytochrome c oxidase [CHIM]Chemical Sciences biology Chemistry Cytochrome c General Chemistry acidophilic bacterium 0104 chemical sciences oxygen reduction electrochemistry Standard electrode potential biology.protein Biophysics |
| Zdroj: | Journal of the American Chemical Society Journal of the American Chemical Society, 2019, ⟨10.1021/jacs.9b03268⟩ Journal of the American Chemical Society, American Chemical Society, 2019, ⟨10.1021/jacs.9b03268⟩ |
| ISSN: | 0002-7863 1520-5126 |
| DOI: | 10.1021/jacs.9b03268⟩ |
| Popis: | International audience; Cytochrome c oxidases (CcO) are the terminal enzymes in energy converting chains of microorganisms where they reduce oxygen into water. Their affinity for O2 makes them attractive biocatalysts for technological devices in which O2 concentration is limited, but the high overpotentials they display on electrodes, severely limit their applicative use. Here, the CcO of the acidophilic bacterium Acidithiobacillus ferrooxidans, is studied on various carbon materials by direct protein electrochemistry and mediated one with redox mediators either diffusing or co-immobilized at the electrode surface. The entrapment of the CcO in a network of hydrophobic carbon nanofibers permits a direct electrochemi-cal communication between the enzyme and the electrode. We demonstrate that the CcO displays a µM affinity for O2, and reduces O2 at exceptionally high electrode potentials in the range of +700-+540 mV vs NHE over a pH range of 4-6. The kinetics of interactions between the enzyme and its physiological partners are fully quantified. Based on these results, an electron transfer pathway allowing O2 reduction in the acidic metabolic chain is proposed. |
| Databáze: | OpenAIRE |
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