title: Characterization by nuclear magnetic resonance of the concanavalin A binding oligosaccharide on the beta b chain of placental beta-hexosaminidase B: lectin binding to the separated polypeptide chains of hexosaminidases A and B.
abstract: The type and distribution of the oligosaccharides on each polypeptide of human placental beta-hexosaminidases A (alpha (beta a beta b)) and B (2(beta a beta b)) were examined. The denatured polypeptides were separated by isoelectric focussing in a polyacrylamide slab gel and each gel was then overlaid with 125I-labelled lectins. The study indicated that the beta a chain contains negligible carbohydrate, the beta b chain contains both the high-mannose and a complex type oligosaccharide, and the alpha chain contains predominantly high-mannose or hybrid type moieties. Two asparagine-linked high-mannose type oligosaccharides present on the beta b polypeptide of beta-hexosaminidase B were isolated by concanavalin A chromatography and by reverse-phase high pressure liquid chromatography. Proton nuclear magnetic resonance characterization of the oligosaccharides revealed an equimolar glycan mixture of the high-mannose type structure Man5 and Man6.
authors.forename: B F
authors.initials: BF
authors.lastname: O'Dowd
authors.forename: D
authors.initials: D
authors.lastname: Mahuran
authors.forename: D
authors.initials: D
authors.lastname: Cumming
authors.forename: J A
authors.initials: JA
authors.lastname: Lowden
mesh_terms: D001345:Autoradiography; D001665:Binding Sites; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003208:Concanavalin A / Q000378:metabolism*; D005260:Female; D006596:Hexosaminidases / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes; D007700:Kinetics; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009844:Oligosaccharides / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011485:Protein Binding; D014357:Trypsin; D001619:beta-N-Acetylhexosaminidases
chemical_list: D007457:Iodine Radioisotopes; D046911:Macromolecular Substances; D009844:Oligosaccharides; D010446:Peptide Fragments; D003208:Concanavalin A; D006596:Hexosaminidases; D001619:beta-N-Acetylhexosaminidases; D014357:Trypsin