Abstract
The structural properties of a key transient oxygen intermediate of cytochrome c oxidase, PR, remain an enigma, although inferences have been drawn from its equilibrium analogues, PCO/O2, PH and P M. With resonance Raman spectroscopy, an oxygen isotope-sensitive band at 806 cm-1 was observed in PCO/O2 produced by adding CO and O2 to the resting enzyme. The vibrational band shifted to 771 cm -1 upon isotopic substitution of 16O2 with 18O2. The same modes at 806 and 771 cm-1 were present simultaneously when the mixed isotope, 18O16O, was employed, indicating that in PCO/O2 the O-O bond is cleaved, resulting in a Fe4+O2- structure. This result unifies the nature of the three equilibrium analogues of the PR intermediate.
Original language | English (US) |
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Pages (from-to) | 6361-6364 |
Number of pages | 4 |
Journal | FEBS Letters |
Volume | 579 |
Issue number | 28 |
DOIs | |
State | Published - Nov 21 2005 |
Keywords
- Bioenergetics
- Biophysics
- Ferryl
- Proton pumping
- Raman
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology