Sulforhodamine GM1-ganglioside: synthesis and physico-chemical properties

Abstract A fluorescent derivative of GM 1 -ganglioside was synthesized by linking sulforhodamine 101 to the sphingosine moiety through amino dodecanoyl residue. The product (SR-12GM 1 ) was quantitatively converted to SR-12GM 2 by treatment with bovine testes β-galactosidase and in intact cultured human skin fibroblasts was catabolized to sulforhodamine GM 2 , GM 3 and ceramide; the latter product was further converted to sphingomyelin. In aqueous medium SR-12GM 1 formed micelles. When transfer from micelles to vesicles and between vesicles was compared with that of pyrene-GM 1 , the transfer of SR-12GM 1 occurred at higher rates, following in both cases a biexponential curve.