Fluorescent BODIPY-labelled GM1 gangliosides designed for exploring lipid membrane properties and specific membrane-target interactions

New fluorophore-labelled GM1 gangliosides have been synthesised and spectroscopically characterised. Spectroscopically different BODIPY groups were covalently linked, specifically to either the polar or the hydrophobic part of the ganglioside molecule. The absorption and fluorescence spectroscopic properties are reported for 564/571-BODIPY- and 581/591-BODIPY-labelled GM1. Each of the different BODIPY groups is highly fluorescent and depolarisation experiments provide molecular information about the spatial distribution in lipid bilayers, as well as order and dynamics. From experiments performed on two spectroscopically different BODIPY:s, specific interactions can be revealed by monitoring the rate/efficiency of donor-acceptor electronic energy transfer. Systems of particular interest for applying these probes are e.g. mixtures of lipids, and peptides/proteins interacting with lipid membranes.