Glycoproteins, sialylated

The increase in incorporation into polypeptides of lower molecular weights may be due to their faster diffusion rate in membrane, thus allowing them to undergo faster sialylation than the higher molecular weight species. This proposition is based on the assumption that there is only one species of glycoprotein sialyl-transferase, an assumption, which is evident later, may not be true. 

Glycoprotein sialylation in plants Reply. Nature Biotechnol 22 1352-1353. 

P-selectin EC, platelets P-selectin glycoprotein ligand-1 (PSGL-1) Sialyl-Lewis" and others... 

The precise chemical nature of some of the ligands involved in selectin-ligand interactions has been determined. All three selectins bind sialylated and fucosy-lated oligosaccharides, and in particular all three bind sialyl-Lewis (Figure 47-12), a structure present on both glycoproteins and glycolipids. Whether this compound is the actual ligand involved in vivo is not estab-... 

The recent impressive work from Hamilton and Gerngross [66] about controlled humanization of iV-glycosylation opened up very attractive perspectives for yeasts for large-scale production of eukaryotic fully humanized sialylated glycoproteins. That makes them serious... 

Independently and at the same time the incorporation of a sialyl-TN-antigen building block in the synthesis of a fragment from the HIV gpl20 glycoprotein was described.41... 

Scheme 13.12 B chain of human a2HS glycoprotein carrying the sialyl-T-antigen.

Figure 14.2 Representative oligosaccharide structures found on mammalian glycoproteins and glycolipids. The complex oligosaccharides may be bi-, tri-, or tetra-antennary the branches may be more or less elongated with 1—>4 linked lactosamine units, and they may or may not be sialylated. The SLex, Lea, and Leb structures represent the different blood group determinants often present on lipids, and the elongated core 2 structure is a mucin-type glycosylation. Proteoglycans have a common core to which a variety of linear acidic polysaccharides are attached.

The initial step in the sequence of events leading to influenza virus infections in mammalian hosts is mediated by the multiple attachment of virus particles to host sialoside receptors in the nasopharynx [41]. These receptors consist largely of cell surface sialylated glycoproteins and gangliosides. The subsequent steps involve receptor-mediated endocytosis with ensuing release of the viral nucleo-plasmid. The first event responsible for the receptor-virus interaction is therefore an attractive target for both antiviral and related microbial intervention. 

Carbohydrate-mediated cell adhesion is an important event which can be initiated by tissue injury or infection and is involved in metastasis. One such adhesion process is the interaction between the glycoprotein E-selectin and oligosaccharides on the surface of neutrophils (white blood cells). The ligand that E-selectin recognizes is the tetrasaccharide sialyl Lewis X (SLe ). Since SLe competes with white blood cells for binding to E-selectin, thus inhibiting the adhesion process, it may useful as an anti-inflammatoiy and anticancer agent. 

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