title: Primary structure of two sialylated triantennary glycans from human serotransferrin.
abstract: Glycopeptides obtained from human serotransferrin by pronase digestion were separated into two fractions by affinity chromatography on Con A-Sepharose. The retarded fraction (85% of total glycopeptides) contained sialylated biantennary glycans of the N-acetyllactosaminic type, the primary structure of which has been previously determined. The non-retained fraction (15% of total glycopeptides) consisted of two isomeric triantennary glycans of the N-acetyllactosaminic type. The primary structure have been elucidated by methylation analysis and 500 MHz 1H-NMR spectroscopy. Both contain an additional NeuAc(alpha 2----3)Gal(beta 1----4)GlcNAc antenna. The latter is linked to C-4 of the (alpha 1----3) bound Man residue in 45% of the glycans in the non-retained fraction but to C-6 of the (alpha 1----6) bound Man residue, in the remaining 55% of the glycans in this fraction.
mesh_terms: D002240:Carbohydrate Sequence; D006020:Glycopeptides / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D011134:Polysaccharides; D011402:Pronase / Q000378:metabolism; D014168:Transferrin
chemical_list: D006020:Glycopeptides; D011134:Polysaccharides; D014168:Transferrin; D011402:Pronase