N-acetylgalactosaminyl disaccharide terminals contained in presumed carbohydrate epitopes specific to sea-squirt allergy.
Using the methods of methylation/GLC, MS, and 1H-NMR analyses, a disaccharide structure of GalNAc alpha 1----2Fuc1---- was identified as one of the major structural units at non-reducing terminals of a highly branched and N-glycosidically linked carbohydrate on an allergenically active glycopeptide, Gp-2 (Mr ca. 8,000). Gp-2 was one of the major fractions in the Pronase digest of a sea-squirt antigen, Gi-rep, and is capable of eliciting the skin reaction specific to patients with sea-squirt allergy similarly to Gi-rep. An additional disaccharide structure of GalNAc1----(3/4)HexNAc1---- was also expected as the other major non-reducing terminal unit, though the anomeric configuration of the terminal GalNAc could not be identified. As Gp-2 carbohydrate was found to contain 3 mol each of the two types of terminal GalNAc-containing units, both were nominated as possible components of the IO4- oxidation-sensitive epitopes which are responsible for the allergenic activity in Gp-2 and its mother antigen, Gi-rep. A few moles of Fuc and Gal were also detected as minor non-reducing terminals in addition to the 6 mol of the GalNAc-containing units.
Shigeta
S
S
Department of Fermentation Technology, Faculty of Engineering, Hiroshima University.
Ono
K
K
Ohta
M
M
Kobayashi
Y
Y
Oka
S
S
D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000032:analysis; D000485:Allergens / Q000276:immunology*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis* / Q000276:immunology; D002849:Chromatography, Gas; D004187:Disaccharides / Q000032:analysis*; D000939:Epitopes / Q000032:analysis*; D005944:Glucosamine / Q000031:analogs & derivatives*; D006967:Hypersensitivity / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D010084:Oxidation-Reduction; D010504:Periodic Acid
D000485:Allergens; D000596:Amino Acids; D002241:Carbohydrates; D004187:Disaccharides; D000939:Epitopes; D010504:Periodic Acid; D005944:Glucosamine; D000117:Acetylglucosamine