Sterol-phospholipid interactions in model lipid membranes

Abstract

Cell membranes feature complex intermolecular interactions between phospholipids and sterols. In this dissertation, I discuss how the accessibility (a measure of chemical activity) of cholesterol in a lipid bilayer varies as a function of bilayer composition. By using the two complementary cyclodextrins (methyl-beta and hydroxypropyl-alpha), I assay the accessibility of both cholesterol and phospholipids for removal from lipid bilayers. Next, I present ternary phase diagrams of mixtures of an unsaturated lipid, a saturated lipid, and one of three different sterols (β-sitosterol, stigmasterol, and ergosterol). Finally, I present research to which I contributed on the thickness mismatch of coexisting liquid phases in model lipid membranes.