Structure of raft-model membrane by using the inverse contrast variation neutron scattering method

✍ Scribed by Mitsuhiro Hirai; Harutaka Hirai; Masaharu Koizumi; Kohji Kasahara; Kohei Yuyama; Naoko Suzuki

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 142 KB
• Volume: 385-386
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.05.129

✦ Synopsis

By means of the inverse contrast variation method in small-angle neutron scattering, we have studied the structure of a small unilamellar vesicle (SUV) composed of ganglioside, cholesterol and dipalmitoyl-phosphocholine. The SUV treated has a similar lipid composition as in a plasma membrane with microdomains, so-called rafts. The present results indicate an asymmetric distribution of lipid components within the bilayer of the vesicle, that is, a predominant distribution of ganglioside and cholesterol at the outer leaflet of the vesicle bilayer. The deviation from the linearity in a pseudo-Stuhrmannplot strongly suggests the presence of a large heterogeneity of lipid composition in a bilayer, namely a clustering of ganglioside and cholesterol molecules. This deviation is enhanced by temperature elevation, meaning that ganglioside-cholesterol clusters become larger with holding liquid-ordered (L o ) phase.