Hybrid sialylated N-glycans are minor constituents of normal BHK-cell glycoproteins and a prominent feature in glycoproteins of some ricin-resistant cell lines.
Baby-hamster kidney (BHK) cells were labelled metabolically by growth in media containing radioactive sugars and the asparagine-linked glycopeptides (N-glycans) obtained by Pronase digestion of disrupted cells were fractionated by chromatography on concanavalin A-Sepharose. About 2-3% of the total [3H]galactose- or [3H]fucose-labelled glycopeptides were found to be bound tightly to the lectin column and were eluted with 500 mM-methyl alpha-mannoside. Further analysis of these minor components by chromatography on Bio-Gel P4, lentil-lectin-Sepharose and DEAE-Sephacel and sensitivity to alpha-mannosidase indicates the presence in BHK-cell glycopeptides of hybrid structures of the following form: (Formula: see text) Similar structures were identified as major features of the glycoproteins of ricin-resistant mutants RicR17 and RicR19 as described previously for RicR21 cells [Hughes, Mills & Stojanovic (1983) Carbohydr. Res. 120, 215-234]. The RicR15 cell line also produces significant amounts of hybrid N-glycans. The studies show that the novel N-glycans accumulating in ricin-resistant mutants are derived by a metabolic pathway that exists to a minor extent in normal BHK cells.
D000818:Animals; D001216:Asparagine / Q000032:analysis; D002460:Cell Line; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006224:Cricetinae; D005690:Galactose / Q000378:metabolism; D006020:Glycopeptides / Q000302:isolation & purification; D006023:Glycoproteins / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008361:Mannosidases / Q000494:pharmacology; D008956:Models, Chemical; D009844:Oligosaccharides / Q000378:metabolism*; D012276:Ricin / Q000494:pharmacology; D014316:Tritium; D043323:alpha-Mannosidase
D006020:Glycopeptides; D006023:Glycoproteins; D009844:Oligosaccharides; C016735:sialooligosaccharides; D014316:Tritium; D001216:Asparagine; D012276:Ricin; D008361:Mannosidases; D043323:alpha-Mannosidase; D005690:Galactose