BODIPY-labeled ganglioside probes for membrane and biological studies

A series of new fluorescent ganglioside G(M1) derivatives bearing the residue of 4,4-difluoro-4-bora-3a,4a-diaza-s-indecene (BODIPY) either in the polar or nonpolar part of the molecule have been synthesized. Gangliosides G(M1) labeled with the residues of (4,4-difluoro-5-styryl-4-bora-3a,4a-diaza-s-indecenyl)-5-pentanoic (564/570-BODIPY-pentanoic) acid and (4,4-difluoro-5-butadienylphenyl-4-bora-3a,4a-diaza-s-indecenyl)-11-undecanoic (581/591-BODIPY-undecanoic) acid at the nonpolar part of the molecule or with the residue of (4,4-difluoro-5-butadienylphenyl-4-bora-3a,4a-diaza-s-indecenyl)-5-pentanoic (581/591-BODIPY-pentaoic) acid at the polar part of the molecule have been synthesized. The spectral characteristics of the resulting probes and their behavior in ganglioside G(M1) micelles and in sphingomyelin-cholesterol enriched bilayers containing BODIPY-FL-labeled gangliosides G(M1) have been studied. The localization of the label in the ganglioside molecule has been demonstrated to affect the efficiency of energy transfer in the case of the corresponding donor-acceptor pairs.