THE DEPENDENCE OF CHOLESTEROL TRANSFER FROM ACHOLEPLASMA-LAIDLAWII LIPOSOMES TO PLASMA-MEMBRANES ON THE CAROTENOIDS CONTENT IN THE MEMBRANES

We studied the dependence of cholesterol transfer from cholesterol-donor vesicles into plasma membranes of A. laidlawii cells on the carotenoid fraction. The levels of cholesterol transfer into the plasma membranes with extracted carotenoids and intact membranes were shown to equal. However, they differed in two-component lipids formed from lecithin and in one of plasma membrane lipid fractions. As compared with the other fractions, the carotenoid fraction had the highest affinity to cholesterol. These data suggest that the carotenoid fraction plays the role of a cholesterol receptor in the A. laidlawii plasma membrane.