The oxidation-reduction potentials of cytochrome o + c4 and cytochrome o purified from Azotobacter vinelandii.
Oxidation-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.
D001395:Azotobacter / Q000201:enzymology*; D003580:Cytochromes; D010084:Oxidation-Reduction; D013053:Spectrophotometry
D003580:Cytochromes