Structures of the N‐Linked Oligosaccharides on Human Plasma Vitronectin

Abstract

The structures of N-linked oligosaccharides present on human plasma vitronectin were elucidated. Oligosaccharides were released from the vitronectin by N-glycosidase F digestion and tagged with 2-aminopyridine ; the pyridylamino-oligosaccharides were then fractionated by anion-exchange and reverse-phase HPLC. Ten major pyridylamino-oligosaccharides were isolated. The linkages and locations of sialic acid residues were determined by desialylation with Salmonella sialidase in combination with acid. The asialo forms were then analyzed by two-dimensional sugar mapping, component sugar analysis and 400-MHz 'H-NMR spectroscopy. The major oligosaccharides of human vitronectin were of the diantennary N-acetyllactosamine type, with a lesser amount of the tri-and a small amount of the monoantennary type, to which 1-3 mol sialic acid residues were linked, mostly through a2-6 linkages, although a2-3 linkages were also present. The possibility that several binding activities of vitronectin can be ascribed to its glycan moiety was discussed, based on the specific features of the N-linked oligosaccharides on human vitronectin revealed here.

Concerted functions ofStreptococcus gordoniisurface proteins PadA and Hsa mediate activation of human platelets and interactions with extracellular matrix

“…Our data suggest that binding of streptococcal cells to Vn is dependent on glycan moieties, in particular sialic acid, because sialidase treatment of Vn led to ablation of streptococcal cell adhesion. The major N-linked oligosaccharides of Vn consist of the N-acetyllactosamine type, with a major proportion of them sialylated (Ogawa et al, 1995). Our adherence data for knock-out and complemented mutants strongly suggest that both Experiments investigating adherence to salivary pellicle and biofilm formation set out to determine if there were roles for the PadA and Hsa proteins in oral cavity colonization outside of pathogenesis within the circulatory system.…”

“…The major N ‐linked oligosaccharides of Vn consist of the N ‐acetyllactosamine type, with a major proportion of them sialylated (Ogawa et al . , ). Our adherence data for knock‐out and complemented mutants strongly suggest that both PadA and Hsa are involved in Vn recognition, since complementation of Δ padA Δ hsa double knock‐out mutants with either PadA or Hsa was not sufficient to restore Vn binding.…”