Redox linked conformational changes in cytochrome c oxidase Perrulla Wittung., Bo G. Malmstrom. FEBS Letters 388 (1996) 47-49

SUMMARY: The CD spectrum of oxidized cytochrome oxidase in the wavelength region 185-260 nm shows that the secondary structure of the protein consists of close to 40% "helix end slightly less than 20% b structure. CD spectra of oxidized cytochrome oxidase, of half and fully reduced carboxy cytochrome oxidase as well as fullyr reduced cytochrpme oxidase have been recorded in the wavelength range of 200-260 nm. The results demonstrate a conformational change on going from the oxidized to the half reduced state in carboxycytochrome oxidase; no further change occurs on full reduction. A conformational change is also seen in the fully reduced enzyme without bound CO. The conformational transitions. are suggested to be part of the proton pumping mechanism of cytochrome oxidase.