Virus oligosaccharide processing

In order to prevent infection, for example, with an influenza virus, it is necessary to block at least one out of two of the substances present on its surface One of them is a neuraminidase, an enzyme that cleaves off sialic acid, and the other is a hemagglutinin, a sialic acid-specific lectin which aids the influenza viruses in docking onto oligosaccharides exposing sialic acid on the surface of host cells. Both compounds are prerequisite for the infection process. 

Located at the terminus of numerous cell-surface oligosaccharides, sialic acids are ideally positioned to participate in biological processes including cell-biomolecule-mediated recognition phenomena, acting as receptors for viruses and bacteria, cellcell communication, and as markers in certain diseases [9, 27, 29],... 

The spikes are of two types. One type (haemagglutinin) has a vital role in the first stages of infection, the penetration of host cells. The second type of spike is made of an enzyme called sialidase, whose role is to help newly formed viruses escape from the host cell so that they can move on to infect other cells. As part of this process, sialidase cleaves off sialic acid from oligosaccharides (short chains of carbohydrate units). These sialidase spikes have clefts that contain an acti ve site, into which bound sialic acid (Structure 3.1) fits during the cleavage process. This active site... 

Tabas, I., Schlesinger, S. Komfeld, S. (1978) Processing of High Mannose Oligosaccharides to Form Complex Type Oligosaccharides on the Newly Synthesised Polypeptides of the Vesicular Stomatitis Virus G Protein and the IgG Heavy Chain , Journal of Biological Chemistry, 253, 716-22... 

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