The oxidation-reduction potentials of cytochrome o + c4 and cytochrome o purified from Azotobacter vinelandii

摘要

pOxidation-reduction titrations of Azotobacter vinelandii cytochrome o + c4 and cytochrome o were performed with simultaneous potential and absorbance measurements under anaerobic conditions. Cytochrome c4 has a midpoint potential (Em, 7.4) of 260mV and purified cytochrome o has an Em, 7.4 of ?18mV. Little change in the midpoint potential of cytochrome o was observed when titrated in the pH range 6.2–9.8./p