Self-aggregation - An intrinsic property of GM1 in lipid bilayers

Abstract

We demonstrate that the ganglioside GM1 in lipid bilayers of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) exhibits a non-uniform lateral distribution, i.e., enriched regions of GM1 molecules are formed, which is an argument in favour of self-aggregation of GM1 being an intrinsic property of GM1 ganglioside. This was concluded from energy transfer/migration studies of BODIPY-labelled gangliosides by means of time-resolved fluorescence lifetime and depolarization experiments. Three fluorophore-labelled gangliosides were synthesized to include either of two spectroscopically different BODIPY groups. These were specifically localized either in the polar headgroup region or in the non-polar region of the lipid bilayer. An eventual ganglioside-ganglioside affinity/aggregation induced by the BODIPY groups was experimentally excluded, which suggests their use in examining the influence of GM1 in more complex systems. © 2007 Informa UK Ltd.