Novel surface phase containing cholesteryl esters. 1. Structural characteristics determined from surface pressure-area measurements

Publisher Website
Google Scholar
Abstract
The behavior of cholesteryl myristoleate in mixtures with dioleoylphosphatidylcholine was investigated at the air-water interface. In addition to the previously described monolayer phase a 2nd surface phase was identified. Analysis of surface pressure and molecular area data as a function of composition shows that the molecules in the 2nd phase can exist in 2 miscible, double-layer states or packing arrangements, only 1 of which contains lecithin. The mixed double-layer state is preferentially formed and has stoichiometry ranging between 2.0 and 9.5 molecules of cholesteryl ester for each lecithin molecule. The structure of this state resembles a mixed monolayer of pressure-dependent composition and area which is covered by a 2nd layer of cholesteryl ester at 38.2 .ANG.2/molecule. The cholesteryl myristoleate/lecithin ratio of the layer in contact with the aqueous phase ranges from 0-2.8 between 39 and 0 mN/m. The 2nd double-layer state is equivalent to a monolayer of cholesteryl ester at the lipid-water interface, covered by a layer of cholesteryl ester molecules at 38.2 .ANG.2. The presence of lecithin at a lipid-water interface has a definite ordering effect on cholesteryl ester molecules at least 30-50 .ANG. from the interface.

This publication has 0 references indexed in Scilit: