Sequential Metabolism of 7-Dehydrocholesterol to Steroidal 5,7-Dienes in Adrenal Glands and Its Biological Implication in the Skin
Figure 10
Stimulation of 7DHC transfer between membranes and the inhibition of the side chain cleavage of [cholesterol by 7DHC.
A. To study 7DHC transfer between membranes by N-62 StAR protein cholesterol or 7DHC was placed in donor vesicles at a molar ratio to phospholipid of 0.2. The transfer of the sterol to acceptor vesicles at 35°C was measured in the presence or absence of 5 µM N-62 StAR protein. B. Inhibition of the side chain cleavage of [4-14C]cholesterol by 7DHC was determined with substrate and cytochrome P450scc incorporated into phospholipid (PL) vesicles prepared from dioleoyl phosphatidylcholine containing ardiolipin. As indicated in the figure, 7DHC was included in the membrane at a molar ratio to phospholipid of 0.2. The rate of side chain cleavage of [4-14C]cholesterol was determined from the amount of [4-14C]pregnenolone formed.