Characterization of the neutral glycopeptides containing the structure alpha-L-fucopyranosyl-(1 leads to 3)-2-acetamido-2-deoxy-D-glucose from human neuroblastoma cells.
Human tumor cells of neurectoderm origin contain a high proportion of alpha-L-fucosyl linkages were determined by high-resolution, 500-MHz, 1H-n.m.r. spectroscopy which gave signals characteristic for alpha-L-Fucp-(1 leads to 3)-D-GlcNAc residues these L-fucosyl residues. This was shown by use of a specific alpha-L-fucosidase from almond emulsin and a broad-spectrum alpha-L-fucosidase from rat testes. The exact alpha-L-fucosyl linkages were determined by high-resolution, 500-MHz, 1H-n.m.r. spectroscopy which gave signals characteristic for alpha-L-Fucp-(1 leads to 3)-D-GlcNAc residues linked to branches and for alpha-L-Fucp-(1 leads to 6)-D-GlcNAc residues linked to the core. More than 95% of the asparagine-linked GlcNAc residues were substituted with (1 leads to 6)-alpha-L-fucosyl groups. Further definition of the range of neutral glycopeptides was obtained with immobilized lectins. Binding to E-PHA-agarose suggested the presence of a beta-D-mannopyranosyl residue substituted at O-4 by a 2-acetamido-2-deoxy-D-glucopyranosyl group. alpha-L-Fucp-(1 leads to 3)-GlcNAc interfered with this binding since removal of alpha-L-fucosyl groups by almond emulsin alpha-L-fucosidase increased the binding by 100%. These studies demonstrate the ability of a combination of high-resolution 1H-n.m.r., enzyme degradation, and lectin-binding affinities to delineate structural elements of small amounts of oligosaccharide residues.
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002460:Cell Line; D002846:Chromatography, Affinity / Q000379:methods; D004187:Disaccharides / Q000302:isolation & purification*; D006020:Glycopeptides / Q000302:isolation & purification*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008970:Molecular Weight; D009447:Neuroblastoma / Q000032:analysis*; D051381:Rats; D013737:Testis / Q000201:enzymology; D005644:alpha-L-Fucosidase
D004187:Disaccharides; D006020:Glycopeptides; D005644:alpha-L-Fucosidase