Calorimetric Investigation of the Influence of Cholesterol on the Transition Properties of Bilayers Formed from Synthetic l-α-Lecithins in Aqueous Suspension

Abstract

nature of the intermediate fluid condition of lecithin hydrocarbon chains (8), the phase boundaries of cholesterol-liquid crystal lecithin and cholesterol-gel phase lecithin systems should be similar.In both cases, the upper half of the fatty acid chains, which parallel the steroid nucleus, are restricted to about the extent of a gel phase hydrocarbon chain.An interesting point of comparison is that our model phase gives an area for two lecithins plus one cholesterol of about 135 A and the area obtained by Lecuyer and Dervichian (10) (see their Fig. 5) is about 138 AZ.We, therefore, argue that our model building approach and the principle of cholesterol solvation should be generally applicable to lecithin-cholesterol mixtures at less than 33 mole per cent cholesterol.