Influence of alpha-hydroxylation of glycolipids on domain formation in lipid monolayers.
By means of fluorescence and scanning force microscopy (SFM), we investigated the phase behavior of lipid monolayers composed of a mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, sphingomyelin, and cholesterol (5/2/3) with either alpha-hydroxylated or nonhydroxylated galactocerebroside. Fluorescence images of lipid monolayers at the air-water interface demonstrate that, independent of the lipid mixture, phase separation occurs at low surface pressure up to 4-6 mN m(-1), while an almost homogeneous phase is observed at larger surface pressures. However, by means of SFM of lipid monolayers transferred by the Langmuir-Blodgett technique at around 30 mN m(-1), nanometer-sized domains became discernible in those lipid mixtures that contained galactocerebroside, while, in that without a glycolipid, no such domain formation was visible. Moreover, the alpha-hydroxy group of the galactocerebroside alters the size and the total area of the domains significantly.
Windschiegl
Barbara
B
Institut für Analytische Chemie, Chemo- und Biosensorik, Universität Regensburg, 93040 Regensburg, Germany.
Steinem
Claudia
C
D006017:Glycolipids / Q000737:chemistry*; D006900:Hydroxylation; D018625:Microscopy, Atomic Force; D015394:Molecular Structure
D006017:Glycolipids