Kinetic Isotope Effects in Cytochrome P-450-Catalyzed Oxidation Reactions. II. Interactions of Cytochrome P-450 with Substrates and Nadph-Cytochrome % MathType!MTEF!2!1!+-% feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabm4yayaaDa% aaaa!3700!$$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{c} $$ Reductase

The liver microsomal cytochrome P-450-containing mixed function oxidase system is responsible for the metabolism of endogenous as well as exogenous compounds such as drugs, Mutagens and carcinogens. Purification and reconstitution studies have established that the basic components of this enzyme system are cytochrome P-450, NADPH-cytochrome c reductase (NADPH-cytochrome P-450 reductase) and phospholipid (Du et al., 1969). Recently, a family of cytochrome p-450 isozymes have been isolated and characterized (Coon et al., 1977; Lu and West, 1978; Johnson, 1979; Guengerich, 1979). These cytochrome P-450 isozymes differ in their minimum molecular weights, spectral, catalytic, immunological and structural properties. NADPH-cytochrome c reductase, a flavoprotein, has also been purified and characterized (Vermilion and Coon, 1978; Gum and Strobel, 1979; Yasukochi et al., 1979).