Compelling EPR evidence that the alternative oxidase is a diiron carboxylate protein

Anthony L. Moore, Jane E. Carré, Charles Affourtit, Mary S. Albury, Paul G. Crichton, Kiyoshi Kita, Peter Heathcote

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49 Citations (Scopus)


The alternative oxidase is a respiratory chain protein found in plants, fungi and some parasites that still remains physically uncharacterised. In this report we present EPR evidence from parallel mode experiments which reveal signals at approximately g = 16 in both purified alternative oxidase protein (g = 16.9), isolated mitochondrial membranes (g = 16.1), and in trypanosomal AOX expressed in Escherichia coli membranes (g = 16.4). Such signals are indicative of a dicarboxylate diiron centre at the active site of the enzyme. To our knowledge these data represent the first EPR signals from AOX present in its native environment.

Original languageEnglish
Pages (from-to)327-330
Number of pages4
JournalBiochimica et Biophysica Acta - Bioenergetics
Issue number4
Early online date17 Jan 2008
Publication statusPublished - Apr 2008
Externally publishedYes


  • Alternative oxidase
  • Diiron
  • Electron transfer
  • Monotopic integral membrane protein
  • Respiration

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