[Alteration of the lipid composition of rat liver microsomes on reconstitution of the cytochrom P-450 system. Inactivation of the enzyme by lysolecithin].

The lipid composition of rat liver microsomes, their "ghosts" and the reconstituted membrane hydroxylation system was investigated. The phospholipid content and composition of the reconstituted membranes were found to depend on the reconstitution method. The reconstituted membranes contained besides phospholipids also cholesterol and gangliosides. The cholesterol/phospholipid ratio of the reconstituted membranes was the same as that of the initial microsomes. Lysolecithin was shown to enhance the conversion of the active form of cytochrom P-450 to the inactive cytochrome P-420.