Accessibility of the cytochrome a heme in cytochrome c oxidase to exchangeable protons

P. V. Argade, Y. C. Ching, M. Sassaroli, D. L. Rousseau

Research output: Contribution to journalArticle

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The comparison of the resonance Raman spectrum of cytochrome a2+ from cytochrome oxidase in deuterated buffers to that in protonated buffers reveals many lines that have different frequency or intensity. Some of the frequency differences are very large, e.g. on the order of 10 cm-1. From these differences in the Raman spectra, we infer that the heme pocket is readily accessible to protons and that labile groups are either on the heme or interact strongly with it. These data suggest the possibility of direct participation in proton translocation and/or oxygen protonation by the heme of cytochrome a.

Original languageEnglish (US)
Pages (from-to)5969-5973
Number of pages5
JournalJournal of Biological Chemistry
Issue number13
Publication statusPublished - Dec 1 1986
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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