The high mannose oligosaccharides of Dictyostelium discoideum glycoproteins contain a novel intersecting N-acetylglucosamine residue.
Previous studies have shown that the majority of the asparagine-linked high mannose oligosaccharide units present on the lysosomal enzymes of the slime mold Dictyostelium discoideum contain mannose 6-sulfate and mannose 6-phosphate residues, the latter being diesterified to methyl groups. Using a variety of techniques, including NMR spectroscopy and fast atom bombardment mass spectrometry, we have found that many of these oligosaccharides also contain an N-acetylglucosamine residue linked beta 1-4 to the mannose residue linked alpha 1-6 to the beta-linked core mannose. (Formula: see text) As far as we are aware, this is the first description of an intersecting N-acetylglucosamine residue in this position on a high mannose oligosaccharide.
D000117:Acetylglucosamine / Q000032:analysis; D002240:Carbohydrate Sequence; D004023:Dictyostelium / Q000032:analysis*; D005656:Fungal Proteins / Q000302:isolation & purification*; D006023:Glycoproteins / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000032:analysis; D013058:Mass Spectrometry; D009844:Oligosaccharides / Q000302:isolation & purification
D005656:Fungal Proteins; D006023:Glycoproteins; D009844:Oligosaccharides; D008358:Mannose; D000117:Acetylglucosamine