Effect of cholesterol on diffusion in surfactant bilayers.
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.
Pieper
Thorsten
T
University of Dortmund, Exp. Physics III, Dortmund D-44221, Germany. thorsten.pieper@gmx.de
Markova
Svetlana
S
Kinjo
Masataka
M
Suter
Dieter
D
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
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