Characteristic binding of human plasma apolipoprotein B to gangliotetraosylceramide and gangliotriaosylceramide.
The binding of human plasma low-density lipoproteins (LDL), freshly prepared by discontinuous ultracentrifugation, to several neutral and acidic glycosphingolipids was examined by TLC immunostaining with the anti [apolipoprotein B (apoB)] antibody. ApoB was found to bind characteristically to the asialogangliosides, gangliotetraosylceramide (Gg4Cer) and gangliotriaosylceramide (Gg3Cer), the former being a more potent receptor than the latter, indicating that the sequences Gal beta 1-3GalNAc beta 1-4Gal and GalNAc beta 1-4Gal are involved in the binding of apoB. A weak positive reaction with fucosylgangliotetraosylceramide (IV2Fuc-Gg4Cer), which has the same internal recognition sequences, was also observed (the binding ability was only 1/7 of that in the case of Gg4Cer). No binding to other neutral glycosphingolipids, or glycosphingolipid sulfates (I3-SO3-GalCer) and gangliosides, was detected, and therefore substitution of the receptor glycolipid with sialic acid was thought to inhibit the binding. The results indicate that, along with the binding of apoB to the LDL-binding domain of the receptor glycoprotein, interaction with some carbohydrate chains in the receptor, or with glycolipids coexisting on the plasma membrane, may be important for the binding of apoB to cells.
Department of Biochemistry, Faculty of Medicine, University of Tokyo, Japan.
J
J
Ledvinova
M
M
Iwamori
Y
Y
Nagai
D001055:Apolipoproteins B / Q000097:blood / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002855:Chromatography, Thin Layer; D003902:Detergents; D005732:Gangliosides; D006028:Glycosphingolipids / Q000378:metabolism*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008969:Molecular Sequence Data; D013194:Staining and Labeling
D001055:Apolipoproteins B; D003902:Detergents; C011258:G(A1) ganglioside; D005732:Gangliosides; D006028:Glycosphingolipids; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; C038244:ganglio-N-triaosylceramide