Service interruption on Monday 11 July from 12:30 to 13:00: all the sites of the CCSD (HAL, EpiSciences, SciencesConf, AureHAL) will be inaccessible (network hardware connection).
Skip to Main content Skip to Navigation
Journal articles

Catalytic intermediates of cytochrome bd terminal oxidase at steady-state: ferryl and oxy-ferrous species dominate.

Abstract : 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.
Document type :
Journal articles
Complete list of metadata

Cited literature [62 references]  Display  Hide  Download

https://hal-riip.archives-ouvertes.fr/pasteur-00975925
Contributor : Istituto Pasteur Fondazione Cenci Bolognetti Connect in order to contact the contributor
Submitted on : Wednesday, April 9, 2014 - 12:57:04 PM
Last modification on : Wednesday, November 3, 2021 - 2:18:08 PM
Long-term archiving on: : Monday, April 10, 2017 - 11:35:25 AM

File

Borisov2011.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Vitaliy B Borisov, Elena Forte, Paolo Sarti, Alessandro Giuffrè. Catalytic intermediates of cytochrome bd terminal oxidase at steady-state: ferryl and oxy-ferrous species dominate.. Biochimica et Biophysica Acta (BBA) - Enzymology, Elsevier, 2011, 1807 (5), pp.503-9. ⟨10.1016/j.bbabio.2011.02.007⟩. ⟨pasteur-00975925⟩

Share

Metrics

Record views

20

Files downloads

127