Structures of the N-linked oligosaccharides on porcine plasma vitronectin.
The structures of N-linked oligosaccharides, especially the distribution of sialic acid species, present on porcine plasma vitronectin were elucidated. Oligosaccharides were released from the vitronectin by N-glycosidase F digestion and tagged with 2-aminopyridine, and the pyridylamino-oligosaccharides were fractionated by anion-exchange and reverse-phase HPLC. Nine major pyridyl-amino-oligosaccharides were isolated. The linkages and locations of sialic acids were determined by a novel approach involving desialylation with Salmonella sialidase in combination with acid desialylation. After desialylation, the asialo-forms were analyzed by two-dimensional sugar mapping, component sugar analysis and 400-MHz 1H-NMR spectroscopy. The major oligosaccharides of porcine vitronectin were of the fucosylated biantennary type, with a small amount of the triantennary N-acetyllactosamine type, to which 1-3 mol sialic acids was linked. Sialic acids were linked predominantly through alpha 2-6 linkages, although alpha 2-3 linkages were also present, and fucose was linked to the innermost N-acetylglucosamine through an alpha 1-6 linkage. It was found that every pyridylamino-oligosaccharide population contained N-glycolylneuraminic acid and N-acetylneuraminic acid in a molar ratio of 1:2-9, and that N-glycolylneuraminic acids were located predominantly on the Man alpha 1-6 arm.
Yoneda
A
A
Department of Chemistry, Faculty of Science, Ochanomizu University, Tokyo, Japan.
Ogawa
H
H
Matsumoto
I
I
Ishizuka
I
I
Hase
S
S
Seno
N
N
D000631:Aminopyridines; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006023:Glycoproteins / Q000097:blood* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D013552:Swine / Q000097:blood; D019096:Vitronectin
D000631:Aminopyridines; D001798:Blood Proteins; D006023:Glycoproteins; D009844:Oligosaccharides; D019096:Vitronectin; D009439:Neuraminidase; C032439:alpha-aminopyridine