The cytochrome c oxidase-azide-nitric oxide complex as a model for the oxygen-binding site.

The complex of cytochrome c oxidase with NO and azide has been studied by EPR at 9.2 and 35 GHz. This complex which shows delta ms = 2 EPR triplet and strong anisotropic signals, due to the interaction of cytochrome a2+3 X NO (S = 1/2) and Cu2+B (S = 1/2), is photodissociable . Its action spectrum is similar to that of cytochrome a2+3 X NO with bands at 430… CONTINUE READING