A novel cholesterol‐based detergent

Abstract

The plasma membrane of eukaryotic cells is a highly organized and dynamic structure. Lipids and proteins are asymmetrically distributed between the leaflets of the membrane bilayer. Several findings also indicate an asymmetrical distribution of lipids between lateral subdomains of the membrane. One such putative subdomain represent rafts, i.e. cholesterol-and sphingolipid-rich domains which can be isolated due to their resistance to solubilization with Triton X-100 at 4°C and their light buoyant density. A special form of rafts are caveolae, flask-shaped invaginations of the plasma membrane that are enriched in the scaffolding protein caveolin. Rafts and caveolae have been implicated in receptor-mediated signal transduction, receptor internalization, intracellular trafficking of cholesterol and cholesterol efflux. Several G protein-coupled receptors The study of integral membrane proteins often requires their purification. The first step in purifying membrane-spanning proteins is to solubilize them from the membrane. Water-soluble amphiphilic molecules (detergents) are used for this purpose. At low concentrations in aqueous solution, detergents exist as monomers. An important parameter of a detergent is its critical micelle concentration (CMC). Above the CMC, micelles are formed due to the amphiphilic nature of the detergent molecules. Amphiphilic membrane components, such as lipids and transmembrane proteins, become incorporated into these detergent micelles, and