Isotopically sensitive branching and its effect on the observed intramolecular isotope effects in cytochrome P-450 catalyzed reactions: a new method for the estimation of intrinsic isotope effects
Two selectively deuterated n-octanes (octane-1-/sup 2/H/sub 3/ and octane-1,2,3-/sup 2/H/sub 7/) were synthesized and subjected to hydroxylation by phenobarbital-induced rat liver microsomes and purified cytochrome P-450b. The results of these experiments provide evidence which clarifies the interplay between a branched reaction pathway and the equilibration of an enzyme-substrate complex, in determining the magnitude of an observed isotope effect. An equation is derived that allows limits to placed on the intrinsic isotope effect. The equation is based on the observed isotope effect and the regioselectivity of a branch reaction pathway, catalyzed by an enzyme that forms two products via a single enzyme-substrate complex. The intrinsic isotope effect for the formation of 1-octanol was determined by this equation to lie between 9.5 and 9.8.
- Research Organization:
- Univ. of Washington, Seattle
- OSTI ID:
- 7031952
- Journal Information:
- J. Am. Chem. Soc.; (United States), Vol. 108:22
- Country of Publication:
- United States
- Language:
- English
Similar Records
Intrinsic isotope effects suggest that the reaction coordinate symmetry for the cytochrome P-450 catalyzed hydroxylation of octane is isozyme independent
Prochiral selectivity and intramolecular isotope effects in the cytochrome P-450 catalyzed omega-hydroxylation of cumene
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DEUTERIUM COMPOUNDS
HYDROXYLATION
ISOTOPE EFFECTS
OCTANE
CHEMICAL REACTION KINETICS
CYTOCHROMES
EXPERIMENTAL DATA
ALKANES
DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
PIGMENTS
PROTEINS
REACTION KINETICS
400202* - Isotope Effects
Isotope Exchange
& Isotope Separation