Receptor Determinant Sialic Acid

Though the role of A-acetylneuraminic acid as a receptor determinant for influenza virus has been known for 40 years, the actual receptor used by this virus to infect cells has not been identified unequivocally. As sialic acid is a frequent sugar on glycoproteins and glycolipids of vertebrate cells, most surface components contain A-acetylneuraminic acid or a derivative of it. All sialylated molecules present on the cell surface are potential receptors for influenza viruses or paramyxoviruses provided they contain sialic acid according to the requirements discussed above (Section 4.1). In the case of erythrocytes, the majority of the surface-bound sialic acid is present on glycophorin. Following isolation from 

Glycolipids are potential receptors also for influenza viruses (Suzuki et al., 1986 Herrler and Klenk, 1987). As discussed above, glycoproteins may function as alternative receptors. Cells that are resistant to infection by influenza C virus because of a lack of receptors, have been shown to become susceptible to infection if they are resialylated with 9-0-acetylated sialic acid (Szepanski et al., 1992). As the a2,6-sialyltransferase used attaches sialic acid specifically to oligosaccharides present on glycoproteins, the virus obviously used glycoprotein receptors to infect these cells. The same approach has been applied to influenza A virus. In this case, cells were pretreated with sialidase to inactivate endoge- 

Recently, sensitive binding assays with proteins immobilized on nitrocellulose have been described to identify sialylated proteins that are recognized by viruses (Schultze et ai, 1993). Applying this method to cell surface proteins, it should be possible to determine the cellular proteins that are likely to function as virus receptors. 

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Herrler G, Hausmann J, Klenk H-D (1995) Sialic acid as receptor determinant of ortho-and paramyxoviruses. In Rosenberg A (ed) Biology of the sialic acids. Plenum Press, New York, p 315... 

Abstract Persistent colonization of the human stomach by Helicobacter pylori is a risk factor for the development of peptic ulcer disease and gastric cancer. Adhesion of microbes to the target tissue is an important determinant for successful initiation, establishment and maintenance of infection, and a variety of different candidate carbohydrate receptors for H. pylori have been identified. Here the different the binding specifities, and their potential role in adhesion to human gastric epithelium are described. Finally, recent findings on the roles of sialic acid binding SabA adhesin in interactions with human neutrophils and erythrocytes are discussed. 

Rogers, G. N. Herrler, G. Paulson, J. C. Klenk, H. D., Influenza C virus uses 9-0-acetyl-N-acetylneuraminic acid as a. high affinity receptor determinant for attachment to cells. JR/o/C/tem 1986,261, (13), 5947-51. Brossmer, R. Gross, H. J., Fluorescent and photoactivatable sialic acids. Methods Enzymol 1994,247,177-93. 

Sialic acid was the first virus receptor identified. Hirst and McClelland and Hare discovered that influenza virus is able to hemagglutinate and that adsorbed virus is eluted from erythrocytes on incubation at 37°C, indicating an enzymatic destruction of a receptor substance on the cells [1, 2]. When a similar enzymatic activity was subsequently detected in Vibrio cholerae cultures, the term receptor-destroying enzyme was introduced [3]. The substance released by the viral enzyme from soluble hemagglutination inhibitors was initially characterized as a carbohydrate of low molecular weight [4] and then identified in crystalline form as A-acetyl-o-neuraminic acid [5]. Thus, it was clear that the receptor determinant of influenza virus was sialic acid and that the viral enzyme was a neuraminidase. Furthermore, for the first time an important biological function of sialic acid had been identified. 

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