Ceramide glycosylation

Lavie Y., Cao H.t., Volner A., Lucci A., Han T.Y., Geffen V., Giuhano A.E., and Cabot M.C., 1997, Agents that reverse multidmg resistance, tamoxifen, verapamil, and cyclosporin A, block gjycosphingolipid metabolism by inhibiting ceramide glycosylation in human cancer cells./. Biol. Chem. 272 1682-1687. 

Liu, Y-Y., Han, T-Y., Giulano, A. E., Hansen, N., and Cabot, M. C., 2000, Uncoupling ceramide glycosylation by transfection of glucosylceramide synthase antisens reverses adiiamycin resistance. J. Biol. Chem. 275 7138-7143. 

Liu YY, Han TY, Giuliano AE, Cabot MC Ceramide glycosylation potentiates cellular multidrug resis-... 

Because membranes components participate in nearly every cell activity their structures are also dynamic and far from the equilibrium states that are most readily understood in biophysical terms. Newly synthesized bilayer lipids are initially associated with endoplasmic reticulum (Ch.3) whereas phospholipids initially insert into the cytoplasmic leaflet while cholesterol and sphingolipids insert into the luminal endoplasmic reticulum (ER) leaflet. Glycosylation of ceramides occurs as they transit the Golgi compartments, forming cerebrosides and gangliosides in the luminal leaflet. Thus, unlike model systems, the leaflets of ER membranes are asymmetric by virtue of their mode of biosynthesis. 

The total synthesis of agelagalastatins 62a and 62b, an antineoplastic glycosphin-golipid, has been achieved by using an a-selective glycosylation of the ceramide... 

Figure 12.14 Monoglycosyl ceramides (cerebrosides). R is an acyl chain. The carbohydrate residue of galactose is shown although this may be replaced by another hex-ose. Glycosyl ceramides containing between two and six carbohydrate residues are also found but only the mono derivatives are referred to as cerebrosides.

Fig. 21.7. Glycosphingolipids and protein glycosylation of Cyclophyllida. Glycolipids of E. multilocularis were analysed by Persat et al. (1990) [1] and (1992) [2]. Glycolipids of T. crassiceps and M. coturnix were characterized by Dennis et al. (1992) [3] and Nishimura etal. (1991) [4], respectively. The major glycolipid of T. solium was analysed by Lopez-Marin etal. (2002) [5], Cer, ceramide. A/-glycans of E. granulosus and O-glycans of . multilocularis were described by Khoo etal. (1997c) [6] and Hulsmeier et al. (2002) [7], respectively. Possible Gala1-4)Gal1- structural elements are boxed.

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