Mixed-function oxygenation of the lower fatty acyl residues. II. The kinetics of microsomal omega- and (omega - 1)-hydroxylation of N-(4-chlorophenyl)propanamide.
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.
D000813:Anilides / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005260:Female; D006900:Hydroxylation; D007700:Kinetics; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D011335:Proadifen / Q000494:pharmacology; D011817:Rabbits
D000813:Anilides; C007021:4-chloropropionanilide; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D011335:Proadifen; D010634:Phenobarbital