Biosynthesis of Lewis antigenic glycolipid by cell-free extracts of human intestinal tumor cells cultured in serum-free medium.
Extracts of the human intestinal tumor cell line SW1116 were able to stimulate the incorporation of (14C) fucose from GDP-(14C) fucose into organically soluble glycolipid. The reaction required a purified glycolipid preparation from human meconium as lipid acceptor. The active glycolipid co-migrated with standard globoside on high performance thin-layer chromatography (HPTLC) and had molecular species (M + H) under fast-atom bombardment mass spectrometry of 1199, 1245 and 1269. Globoside itself was inactive and asialo GM1b had low activity. The radioactive products co-purified with Lewis a and Lewis b and co-migrated principally (60-90%) with Lewis b monoclonal antibody binding cellular glycolipids on HPTLC. Analysis of fucosidase digests suggested the presence of two different fucosyl-hexose linkages one of which was susceptible to cleavage. We conclude that the data are consistent with fucosylation of lactotetraosyl ceramide to Lewis a and Lewis b antigenic glycolipids.
D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D002474:Cell-Free System; D002851:Chromatography, High Pressure Liquid; D005643:Fucose / Q000378:metabolism; D005677:G(M1) Ganglioside; D005915:Globosides / Q000378:metabolism; D006017:Glycolipids / Q000096:biosynthesis* / Q000276:immunology; D006028:Glycosphingolipids / Q000378:metabolism; D006801:Humans; D007414:Intestinal Neoplasms / Q000276:immunology*; D007983:Lewis Blood Group Antigens / Q000276:immunology*; D013058:Mass Spectrometry; D008470:Meconium / Q000032:analysis; D008970:Molecular Weight; D013656:Taurocholic Acid / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D005915:Globosides; D006017:Glycolipids; D006028:Glycosphingolipids; D007983:Lewis Blood Group Antigens; D005643:Fucose; D005677:G(M1) Ganglioside; D013656:Taurocholic Acid; C018835:asialo GM1 ganglioside