Cytochrome bd from Azotobacter vinelandii: Evidence for high-affinity oxygen binding

The basic thermodynamic and kinetic parameters for the reaction of cytochrome bd from Azotobacter vinelandii with oxygen was measured and compared with those of the Escherichia coli enzyme. The results suggest that in cytochrome bd, the redox state of the b-type hemes (heme [b.595]), controls the pathway for ligand transfer between heme d and the bulk phase.