Characterization of asparagine-linked oligosaccharides on a mouse submandibular mucin.
The asparagine-linked oligosaccharides from an adult female mouse submandibular gland mucin were released by treatment with peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F or endo-beta-N-acetylglucosaminidase H. Endo-beta-N-acetylglucosaminidase H appeared to be more effective at releasing the asparagine-linked oligosaccharides from this mucin than was peptide-N4-(N-acetyl-beta-glucosaminyl)-asparagine amidase F. After quantitative reductive labelling with the fluorophore, 8-aminonaphthalene-1,3,6-sulphonic acid, the oligosaccharides were separated by polyacrylamide gel electrophoresis and isolated. The individual oligosaccharides were sequenced by a battery of recombinant exoglycosidases. Approximately 50% of the oligosaccharides were of the high-mannose type. The five-mannose member of this family was the most prevalent. The second group of oligosaccharides were of the non-bisected hybrid type. No complex asparagine-linked oligosaccharides were detected. The hybrids exhibited both biantennary and triantennary branching patterns. The triantennary hybrid was the most common hybrid at > 30% of all oligosaccharides. With approximately 98% of the hybrid oligosaccharides sialylated and all lacking a bisecting N-acetylglucosamine, these oligosaccharides as a group have been only rarely observed in other glycoproteins. The fully sialylated triantennary hybrid may be unique.
Denny
P C
PC
Department of Basic Sciences, School of Dentistry, University of Southern California, Los Angeles 90089, USA.
Denny
P A
PA
Hong-Le
N H
NH
D000818:Animals; D001216:Asparagine / Q000378:metabolism*; D002236:Carbohydrate Conformation; D005260:Female; D051379:Mice; D009077:Mucins / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D013363:Submandibular Gland / Q000378:metabolism*
D009077:Mucins; D009844:Oligosaccharides; D001216:Asparagine