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Kinetic models were constructed for a variety of cytochrome P450-catalyzed reactions involving drug metabolism. The kinetic parameters observed were explained using a two-site model of the enzyme. In this model of cytochrome P450, atypical kinetics from the binding of at least two substrates in the enzyme's binding site is described. This model is used to explain the atypical kinetics of various isoforms of cytochrome P450.

Isotope effect profiles show a hydrogen atom abstraction mechanism for the cytochrome P-450 oxidative dealkylation of substituted N,N-dimethylanilines. For several P-450 oxidants the reaction mechanisms appear to be common, as detected from similar isotope effect profiles. The mechanisms of other amine oxidations by P-450 and oxidations by other hemoproteins may also be investigated by the profiles.

Androstene dione metabolism is examined by isolating the microsomes of Chinese hamster ovary cells that express human aromatase. The restriction of electron flux from NADPH-cytochrome P450 reductase to aromatase results in enhanced quantities of smaller metabolites. The reactions of aromatase and oxidoreductase are indicated by the metabolite ratios.

Cytochrome P450s CYP2A1 and CYP2A2 differ in their regioselectivity for tetosterone hyroxylation where the former metabolizes 90% of testosterone at the 7 alpha-position while the latter forms various hydroxytestosterones. Twenty-six single point and double point mutants were prepared to determine the kinetics of testosterone hydroyxlation. Kinetic analysis revealed that four of the mutants had varied maximum velocity values which may be influenced by the amount of hydrogen peroxide released.