Korrel S A, Clemetson K J, van Halbeek H, Kamerling J P, Sixma J J, Vliegenthart J F
Department of Bio-Organic Chemistry, Utrecht University, The Netherlands.
FEBS Lett. 1988 Feb 15;228(2):321-6. doi: 10.1016/0014-5793(88)80024-3.
Glycocalicin (140 kDa), the main constituent of the glycoprotein Ib alpha-chain (150 kDa) of the human platelet membrane, contains 4 putative N-glycosylation sites. For the structural analysis of the N-glycosidic carbohydrate chains of glycocalicin, the glycoprotein has been subjected to the hydrazinolysis procedure. The acidic carbohydrate chains obtained were fractionated by ion-exchange chromatography on DEAE-Sephadex A-25, and subsequently analyzed by sugar analysis, anion-exchange chromatography on Mono Q HR 5/5 and 500 MHz 1H-NMR spectroscopy. A novel tetrasialylated monofucosylated tetraantennary chain was identified in the glycoprotein. It could also be deduced that in all structures the alpha 2----6-linked NeuAc is attached exclusively at the Gal beta 1----2Man alpha 1----3 antenna, whereas the other antennae can be terminated with alpha 2----3-linked NeuAc. As minor constituents sialylated N-linked carbohydrate chains with a terminal Fuc alpha 1----2Gal beta 1----sequence were detected.
