Sialic-acid-recognizing receptor

Sialic-acid-recognizing receptors have been discovered in a variety of vertebrates, mostly mammalian tissues, summarized in Tables 22-24. This line of research was much stimulated by the discovery of a family of cell adhesion molecules now generally called selectins [1033]. Due to its great importance, this topic has been reviewed frequently [660,828,1034-1039]. It will, therefore, not be discussed in detail here. 

Vlasak R, Luytjes W, Spaan W, Palese P (1988) Human and bovine coronaviruses recognize sialic acid-containing receptors similar to those of influenza C viruses. Proc Natl Acad Sci USA 85 4526-4529... 

The ability of viruses to infect specific cell types is dictated in part by the ability of these viruses to bind to particular structures or receptors on the surfaces of cells. In some cases, these receptors are carbohydrates. For example, influenza virus recognizes sialic acid residues present on cell-surface glycoproteins. The viral protein that binds to these sugars is called hemasslutinin(Fisure 11.31). 

Because of the destabilizing effect of the mutations on the structure of the mutant proteins, the NA mutant and some of the HA mutants display a marked thermo-lability. The NA mutant loses both enzyme activity as well as reactivity to the NC-10 mAb, which only recognizes the native NA (7). The HA mutants lose the ability to bind to the receptor on red blood cells, resulting in a decrease in the hemagglutination titer, or to the sialic acids on fetuin in a fetuin-based ELISA assay. 

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