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- Spillmann, Dorothe, et al.
(författare)
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Characterization of a novel pyruvylated carbohydrate unit implicated in the cell aggregation of the marine sponge Microciona prolifera
- 1993
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 268:18, s. 13378-13387
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Tidskriftsartikel (refereegranskat)abstract
- The species-specific Ca(2+)-dependent reaggregation of dissociated cells of the marine sponge Microciona prolifera is mediated by a large extracellular adhesion proteoglycan. The glycans of this molecule are involved in the interactions of the proteoglycan with itself and with the sponge cells. Monoclonal antibodies against the glycans block the aggregation of sponge cells (Misevic, G. N., Finne, J., and Burger, M. M. (1987) J. Biol. Chem. 262, 5870-5877). Proteoglycan oligosaccharides were prepared by partial acid hydrolysis of the isolated glycans, and their reactivity with the monoclonal antibodies was monitored after linkage to phospholipid and immunostaining of thin layer chromatograms. One major antibody-reactive oligosaccharide was detected and purified by ion-exchange chromatography and high performance liquid chromatography. 1H NMR spectroscopy, fast atom bombardment-mass spectrometry, methylation analysis, and sequential chemical and enzymatic degradation studies indicated the structure [formula: see text] for the oligosaccharide. The depyruvylated derivative of the oligosaccharide did not react with the aggregation-blocking antibody, which indicates that the pyruvate acetal is an essential part of the epitope.
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| 2. |
- Spillmann, Dorothe, et al.
(författare)
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Identification of a major poly-N-acetyllactosamine-containing cell-surface glycoprotein of mouse teratocarcinoma cells : Appearance on cells induced to primitive endoderm but not parietal endoderm differentiation
- 1994
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 220:2, s. 385-394
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Tidskriftsartikel (refereegranskat)abstract
- Mouse teratocarcinoma F9 cells were induced to primitive endoderm differentiation with retinoic acid, and poly-N-acetyllactosamine-containing surface glycoproteins were identified by radiolabelling endo-beta-galactosidase-cleavable glycans with galactosyltransferase and radiolabelled UDP-galactose. One major radiolabelled band with an apparent size of 250-500 kDa was identified which differed from the known poly-N-acetyllactosamine-containing glycoproteins laminin, fibronectin, lysosome-associated membrane protein (LAMP)-1 and LAMP-2. This acidic glycoprotein, resistant to glycosaminoglycan-degrading enzymes and proteases, was purified by extraction and phase partition with Triton X-114, octyl Sepharose and Helix pomatia lectin chromatography. The purified glycoprotein could be digested by endo-beta-galactosidase and glycopeptide N-glycosidase F to an apparent size of 160-240 kDa. During retinoic-acid-induced differentiation into primitive endoderm cells, the glycoprotein showed a several-fold increase and a broadening to an apparent size of 200- > 700 kDa. The glycoprotein was no longer detected in retinoic-acid and dibutyryl-cAMP-treated cells which had undergone further differentiation to parietal endoderm cells, nor in the permanently differentiated parietal endoderm line F9-AC. The results suggest that the glycoprotein is a major carrier of poly-N-acetyllactosamine chains on differentiating teratocarcinoma F9 cells, and that its expression as revealed by the poly-N-acetyllactosamine labelling method is regulated by the stage of cellular differentiation.
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