title: Effect of cholesterol on diffusion in surfactant bilayers.
abstract: Biological membranes consist of lipid bilayers with liquid-ordered and liquid-disordered phases. It is believed that cholesterol controls the size of the microdomains in the liquid-ordered phase and thereby affects the mobility as well as the permeability of the membrane. We study this process in a model system consisting of the nonionic surfactant C(12)E(5) and water in the lamellar phase. We measure the diffusion of fluorescent probe molecules (rhodamine B) by fluorescence correlation spectroscopy. For different surfactant to water ratios, we measure how the molecular mobility varies with the amount of cholesterol added. We find that a reduction of the diffusion coefficient is already detectable at a molar ratio of 8 mol % cholesterol.
authors.affiliation: University of Dortmund, Exp. Physics III, Dortmund D-44221, Germany. thorsten.pieper@gmx.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Pieper
authors.forename: Svetlana
authors.initials: S
authors.lastname: Markova
authors.forename: Masataka
authors.initials: M
authors.lastname: Kinjo
authors.forename: Dieter
authors.initials: D
authors.lastname: Suter
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D010539:Permeability; D011092:Polyethylene Glycols / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004987:Ethers; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D012235:Rhodamines; D013501:Surface-Active Agents; D014867:Water; C077053:pentaethylene glycol monododecyl ether; D011092:Polyethylene Glycols; D002784:Cholesterol; C029773:rhodamine B