PT  - JOURNAL ARTICLE
AU  - V Apostolescu
AU  - W Lenk
TI  - Mixed-function oxygenation of the lower fatty acyl residues. II. The kinetics of microsomal omega- and (omega - 1)-hydroxylation of N-(4-chlorophenyl)propanamide.
DP  - 1981 Jul 01
TA  - Drug Metabolism and Disposition
PG  - 315--321
VI  - 9
IP  - 4
4099  - http://dmd.aspetjournals.org/content/9/4/315.short
4100  - http://dmd.aspetjournals.org/content/9/4/315.full
SO  - Drug Metab Dispos1981 Jul 01; 9
AB  - Investigation of the kinetics of microsomal omega- and (omega - 1)-hydroxylation of 4,'-chloropropionanilide with rabbit liver microsomes revealed normal Michaelis-Menten behavior for that form of cytochrome P-450 which catalyzes omega-hydroxylation, and deviation from Michaelis-Menten behavior for the form(s) of the hemoprotein that catalyze(s) (omega - 1)-hydroxylation. This is deduced from linear Lineweaver-Burk plots of the kinetic data from omega-hydroxylation and from concavely curved downward plots of the kinetic data from (omega - 1)-hydroxylation. Evaluation of the apparent kinetic constants for (omega - 1)-hydroxylation was achieved by means of a computer program developed on the basis of non-linear regression analysis. The effect of inducers of microsomal oxygenases, such as phenobarbital and 3-methylcholanthrene, and of modifiers of microsomal enzyme activities, such as NADH, EDTA, nicotinamide, and SKF 525-A on the kinetics of omega- and (omega - 1)-hydroxylation has been studied. The two types of hydroxylation were affected differently, and different concentrations of the modifiers affected the hydroxylation pattern differently.