Ganglioside headgroups decrease lipid order in reconstituted phosphatidylcholine liposomes.

The effect of oligosaccharide carrying lipids on membrane fluidity has been investigated. Gangliosides GM1 and GQ1 were reconstituted into phosphatidylcholine bilayer membranes at low concentrations (less than 5 mol%). A strong fluidizing effect was observed leading to a suppression of the phase transition temperature. This was most pronounced with highly sialylated gangliosides. Ca2+ reverses the effect due to phase separation phenomena. We assume a hydrophilic lipid-lipid interaction in accordance with previously studied glycoprotein-lipid interactions.