Hydroxylation of fatty acids and alcohols by hepatic microsomal cytochrome P-450 system from the Mongolian gerbil

Abstract

The liver microsomes of the Mongolian gerbil Meriones unguiculatus catalyzed the hydroxylation of various saturated fatty acids (C8-c18), alcohols (C12 and C16) and hydrocarbon (C12) to the corresponding omega- and (omega-1)-hydroxy derivatives. Lauric acid was hydroxylated most effectively among saturated fatty acids and the order of activity as hydroxylation substrates was C12 greater than C14 greater than C13 greater than C16 greater than C10 greater than C18 greater than C8. The specific activity of laurate hydroxylation (5.99 nmol/mg microsomal protein/min) in gerbil liver microsomes was higher than that observed in other species. 1-Dodecanol was also hydroxylated very effectively (4.58 nmol/mg microsomal protein/min) by gerbil liver microsomes, but in general the hydroxylation rates for fatty alcohols were much lower than those for the corresponding acids. It was found from both inhibitor and cofactor studies that the enzyme catalyzing the hydroxylation of fatty acids and alcohols in the liver microsomes of the Mongolian gerbil was a typical cytochrome P-450-linked monooxygenase, and at least two different cytochrome P-450 species were involved in the hydroxylation.