title: Core tetrasaccharide liberated by endo-beta-D-N-acetylglucosaminidase D from lactosamine-type oligosaccharides of Semliki Forest virus membrane proteins.
abstract: [3H]Mannose- and [3H]glucosamine-labeled lactosamine-type glycopeptides of Semliki Forest virus membrane proteins were stripped of their fucose, sialic acid, galactose and distal N-acetylglucosamine residues and subsequently digested with endo-beta-D-N-acetylglucosaminidase D from Diplococcus pneumoniae. Two products were obtained, a neutral tetrasaccharide and a residual glycopeptide fraction. The tetrasaccharide appeared to consist of two alpha-mannose residues, one beta-mannose residue and one N-acetylglucosamine residue located at the reducing terminus of the molecule. Results of Smith degradation, beta-elimination and acetolysis were compatible with four structures; (1) Man alpha-1-3[Man alpha 1-6]Man beta 1-4GlcNAc; (2) Man alpha 1-3Man beta 1-4[Man alpha 1-6] GlcNAc; (3) Man alpha 1-3Man alpha 1-4[Man beta 1-6]GlcNAc, or (4) Man alpha 1-6Man alpha 1-3Man beta-1-4GlcNAc. The reactivity of the viral glycopeptides with endo-beta-D-N-acetylglucosaminidase D and the chromatographic properties of the liberated core tetrasaccharide suggest that its most likely structure was Man alpha 1-3[Man alpha-1-6]Man beta 1-4GlcNAc. The core tetrasaccharide of glycans of membrane protein E3, one of the viral membrane proteins obtained from infected cell, was similar to that of the virion glycans.
mesh_terms: D000118:Acetylglucosaminidase / Q000494:pharmacology; D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000032:analysis; D006020:Glycopeptides / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis; D009844:Oligosaccharides / Q000032:analysis* / Q000302:isolation & purification; D012672:Semliki forest virus / Q000032:analysis*; D014764:Viral Proteins / Q000032:analysis*; D014771:Virion / Q000032:analysis
chemical_list: D002241:Carbohydrates; D006020:Glycopeptides; D008565:Membrane Proteins; D009844:Oligosaccharides; D014764:Viral Proteins; D000118:Acetylglucosaminidase