Serum amyloid P component binds to influenza A virus haemagglutinin and inhibits the virus infection in vitro

摘要: Serum amyloid P component (SAP) is a member of the phylogenetically conserved and structurally related group proteins called pentraxins. SAP exhibits multispecific calcium-dependent binding to oligosaccharides with terminal N-acetyl-galactosamine, mannose glucuronic acid. The authors report that can bind influenza A virus inhibit agglutination erythrocytes mediated by subtypes H1N1, H2N2 H3N2. also inhibits production haemagglutinin (HA) an cytopathogenic effect in MDCK cells. requires physiological calcium concentrations blocked specific antibodies. Denaturated renaturated retained inhibition HA. Electron microscopy shows Ca(2+)-dependent spikes on viral envelope immunoblotting indicates binds 50-55 kDa peptide corresponding mass HA1 peptide. Of several monosaccharides tested only D-mannose interfered SAP's both HA infectivity. glycosaminoglycans heparan sulfate heparin, which SAP, reduced SAPs virus. results indicate due steric effects when localized close sialic acid-binding site trimer.