| 1. |
- Finne, J, et al.
(författare)
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Novel polyfucosylated N-linked glycopeptides with blood group A, H, X, and Y determinants from human small intestinal epithelial cells.
- 1989
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 264:10, s. 5720-35
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Tidskriftsartikel (refereegranskat)abstract
- A novel type of N-linked glycopeptides representing a major part of the glycans in human small intestinal epithelial cells from blood group A and O individuals were isolated by gel filtrations and affinity chromatography on concanavalin A-Sepharose and Bandeiraea simplicifolia lectin I-Sepharose. Sugar composition, methylation analysis, 1H NMR spectroscopy of the underivatized glycopeptides and FAB-mass spectrometry and electron impact-mass spectrometry of the permethylated glycopeptides indicated a tri- and tetra-antennary structure containing an intersecting N-acetylglucosamine and an alpha (1----6)-linked fucose residue in the core unit for the majority of the glycans. In contrast to most glycopeptides of other sources, the intestinal glycopeptides were devoid of sialic acid, but contained 6-7 residues of fucose. The outer branches contained the following structures: Fuc alpha 1-2Gal beta 1-3GleNAc beta 1- (H type 1) Fuc alpha 1-2Gal beta 1-4GleNAc beta 1- (H type 2) Gal beta 1-4 (Fuc alpha 1-3)GlcNAc beta 1- (X) Fuc alpha 1-2Gal beta 1-4(Fuc alpha 1-3)GleNAc beta 1- (Y) GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-3GleNAc beta 1- (A type 1) GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-4GleNAc beta 1- (monofucosyl A type 2) GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-4 (Fuc alpha 1-3)GlcNAc beta 1- (trifucosyl A type 2) The blood group determinant structures were mainly of type 2, whereas glycolipids from the same cells contained mainly type 1 determinants. The polyfucosylated glycans represent a novel type of blood group active glycopeptides. The unique properties of the small intestinal glycopeptides as compared with glycopeptides of other tissue sources may be correlated with the specialized functional properties of the small intestinal epithelial cells.
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| 2. |
- Spillmann, Dorothe, et al.
(författare)
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Poly-N-acetyllactosamine glycans of cellular glycoproteins : predominance of linear chains in mouse neuroblastoma and rat pheochromocytoma cell lines.
- 1987
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Ingår i: Journal of Neurochemistry. - 0022-3042 .- 1471-4159. ; 49:3, s. 874-883
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Tidskriftsartikel (refereegranskat)abstract
- To study the properties of protein-bound oligosaccharides in neuronally differentiating cells, two model systems were used: murine N1E-115 and N-18 neuroblastoma cells inducible by serum starvation and rat PC12 pheochromocytoma cells inducible by nerve growth factor. Glycopeptides were prepared from cells metabolically labeled with [3H]glucosamine and analyzed by gel filtration. The properties of the high-molecular-weight glycopeptides were studied using enzymatic digestion with neuraminidase and endo-beta-galactosidase. In contrast to other cell lines analyzed, the neuroblastoma and pheochromocytoma lines contained predominantly glycopeptides completely cleavable with endo-beta-galactosidase, which indicated that they were linear-type poly-N-acetyllactosamine glycans. The proportion of these linear chains in the high-molecular-weight fraction increased during neuronal differentiation in both cell systems. The linear nature of the glycans was also correlated with positive anti-i and negative anti-I reactivity of the cells in immunofluorescence microscopy. Specific cell surface labeling for poly-N-acetyllactosamine glycans and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed several glycoprotein components, some of which showed changes during neuronal differentiation. The high proportion of linear poly-N-acetyllactosamine chains in these neuronal cell lines and its increase during neuronal differentiation suggests that these glycans may be a characteristic feature of neuronal or neuronally differentiating cells.
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