Type I- Substrate Binding and Oxidase Function of Microsomal Cytochrome P-450
The stoichiometry of hydroxylation reactions re-presents the sum of hydroxylase and oxidase activity (Biochem.Soc.Trans. 3, 807(1975), Arch.Biochem.Biophys. 180, 343(1977)). The latter can be expressed by formation rates of H2O2. As the amount of H2O2 produced varies among others by the addition of substrates, it was postulated (B.B.R.C. 54, 968(1973)) that oxidase, oxygenase and peroxidase function associated with cytochrome P-450 are controlled by the spin state of cytochrome P-450, which can be expressed by e.g. the spectral change elicited by type I binding substrates such as hexobarbital.