Cholesteryl ester distribution in lecithin bilayer membranes

The saturated cholesteryl ester, cholesteryl 16-doxylstearate, is shown to incorporate into hydrated egg yolk lecithin multilayers in two distinct forms as visualized by electron spin resonance (ESR) spectroscopy. At concentrations less than 1 mole%, the ester is uniformly distributed in the membrane while at higher concentrations, patches of solid ester are formed.