TABLE 1

Value of the isotope effect expected for the cytochrome P450 hydroxylation of a substrate at a nondeuterated site by parallel pathway, nondissociative, and dissociative mechanisms determined from competitive and noncompetitive experiments


Isotope Effect

Mechanism
Parallel Pathway
Nondissociative
Dissociative
Competitive VH/VD 1.0 <1.0 1.0
Noncompetitive (V/K)H/(V/K)D
1.0
<1.0
<1.0 to >1.0