リン脂質の指組み構造膜

Abstract

The ability of bilayer lipids to form interdigitated states, in which the acyl chains from opposing monolayers interdigitate, has recently come into focus as a means to significantly alter membrane properties. In addition to changing the membrane thickness and the hydrophobic region of bilayer membranes, the formation of interdigitated membranes alters the electrostatic properties of the membrane surface. A variety of molecules can induce the formation of a fully interdigitated phase by saturated symmetric phospholipids. They include amphipathic molecules such as polyols, short chain alcohols, anesthetics and so on. Common properties are that they do not penetrate too deeply into the hydrocarbon core of bilayer membranes and that they are capable of displacing some of the water molecules associated with the head groups of lipids, thereby creating an increase in the surface area of these groups.In the present review, the forces governing the self-assembly of lipid molecules into interdigitated structures, the physical properties distinctive of interdigitated state membranes and fruitful methods by which interdigitation in membranes may be determined and characterized are outlined along with a detection method developed by the author and coworkers. Mechanisms of phase transition of lipid membranes in the presence of ethanol as an inducer are also proposed and covered together with the results of research concerning the effects of cholesterol on the formation of interdigitated membranes. The possibility of producing formation of interdigitated structures in biomembranes is discussed.