Molecular Level Modeling of the Effects of Charge and Sugars on the Phase Equilibrium of Model Lipid Bilayers

摘要

Research in the functionality of cell membranes has surged over the past decade, beginning with the realization that biological membranes are functionally active, directly governing diverse biological processes. Much progress has been made in detailing the complexities and the organizational tendencies of membrane architecture that confer its physiological activity. Particularly, heterogeneity of lipids within the bilayer manifests as distinct liquid-ordered domains, which contain high concentrations of cholesterol and the structurally-packed saturated lipid components, residing in a liquid-disordered, predominately unsaturated lipidrich medium. These domains may act as platforms that incorporate specific proteins or ions to initiate biochemical processes, such as signal transduction, endo- and exocytosis, transport, and cytoskeleton organization. It has been well documented experimentally that a condition for such phase coexistence is the system’s inclusion of high (saturated) and low (generally unsaturated) melting temperature lipids and a sterol, such as cholesterol.