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Query: UMLS:C0272170 (SDS)
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Encephalomyocarditis and influenza viruses attach to human erythrocytes causing haemagglutination. The receptor for both viruses on these cells is the major membrane sialoglycoprotein, glycophorin, solubilized preparations of which inhibit haemagglutination by either virus. We show here that glycophorin preparations inhibited haemagglutination of both viruses, even after the preparations were digested with chymotrypsin. To determine which component(s) in the digest exhibited activity, peptides separated by gel filtration were assayed for haemagglutination inhibition; one peptide only, CH-0, was active. A tentative structure was deduced for CH-0 from amino acid and sialic acid analyses. It was already known that neuraminidase treatment of erythrocytes or glycophorin prevents interaction with either virus, suggesting that sialic acid may form part of the active binding site in the receptor. However, receptor activity requires more than the presence of a particular arrangement of sialic acid since the arrangement in CH-0 was identical to that in two other inactive chymotryptic peptides. Examination by gel filtration, sucrose density gradient centrifugation and SDS-polyacrylamide gel electrophoresis demonstrated that Ch-0 readily aggregated, unlike the inactive peptides. It was proposed that the CH-0 chymotryptic peptide showed receptor-like activity (inhibited haemagglutination) because its tendency to aggregate allowed strong multivalent binding with virus particles.
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PMID:A sialoglycopeptide from human erythrocytes with receptor-like properties for encephalomyocarditis and influenza viruses. 630 11

Sialoglycoprotein which exhibits inhibitory activity for hemagglutination by Hemagglutinating Virus of Japan (HVJ, Sendai virus) was isolated from the membrane of bovine erythrocytes. Purification steps for this sialoglycoprotein included extraction with lithium diiodosalicylate, phenol partition, precipitation with ethanol, and chromatography on a phosphocellulose column and an SDS-Sepharose CL-4B column. Purified sialoglycoprotein (GP-2) has high specific activity for inhibiting the hemagglutination with HVJ, and a lesser activity for that with Newcastle disease virus, but it does not inhibit the hemagglutination by influenza A virus. Inhibitory activity of GP-2 on hemagglutination by HVJ is 2,500-fold higher than that of fetuin. Liposomes containing a 10,000-fold larger amount of ganglioside mixture of bovine erythrocytes and those containing a 5,000-fold larger amount of each ganglioside of bovine erythrocytes, N-glycolylneuraminosyl-lactosyl ceramide, sialosyllacto-N-neotetraosyl- and sialosyl-lacto-N-norhexaosyl ceramide, had no inhibitory activity toward hemagglutination with HVJ. GP-2 (mol. wt. 250 K daltons) behaved homogeneously in SDS-polyacrylamide gel electrophoresis. It contained 70% carbohydrate and 30% protein, by weight. N-Acetylgalactosamine, N-acetylglucosamine, galactose, sialic acid (N-glycolylneuraminic acid, 96%; N-acetylneuraminic acid, 4%) were identified as carbohydrate components, in molar ratios of 1.0:4.0:5.2:2.9. All the oligosaccharides of GP-2 appeared to be linked to polypeptide chains by alkali-labile O-glycosidic linkages. Sialidase treatment of GP-2 and conversion of sialic acid residue of the glycoprotein to C8 and C7 analogues resulted in the loss of the inhibitory activity on hemagglutination by HVJ. Oligosaccharides isolated by gel filtration after treatment of GP-2 with alkaline borohydride had also lost the ability to inhibit the hemagglutination by HVJ. The above results indicate that isolated sialoglycoprotein is the endogenous receptor in bovine erythrocyte membrane specific to HVJ, and the hydroxy group linked to the 9-carbon atom of sialic acid and probably also the hydrophobic protein moiety are important for the recognition of HVJ attachment.
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PMID:Isolation and characterization of receptor sialoglycoprotein for hemagglutinating virus of Japan (Sendai virus) from bovine erythrocyte membrane. 630 60

The small chain of influenza virus haemagglutinin, HA2 was isolated by a selective enzymic removal of HA1 or by preparative SDS-polyacrylamide gel electrophoresis. Anti-HA2 specific antisera and monoclonal antibodies were subtype-specific in immunodiffusion tests and radioimmunoassays. These antibodies did not inhibit haemagglutination or haemolysis, did not prevent virus release, did not neutralize infectivity, and HA2 did not induce a protective immunity. HA2-specific antigenic determinants could not be demonstrated on the surface of infected cells. Lymphocytes from pre-immunized mice could not be stimulated by HA2 to exert a cytotoxic effect.
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PMID:Immunogenic properties of the small chain HA2 of the haemagglutinin of influenza viruses. 636 20

Monovalent whole virus and Tween-ether split vaccines prepared from influenza A/Bangkok, A/Brazil and B/Singapore were assayed for haemagglutinin content using single radial immunodiffusion (SRID), quantitative sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunization of guinea pigs. When SRID was performed with split vaccines, haemagglutinin values were consistently recorded which were in the range of 50 to 25% of the values obtained before disruption of virions. When, however, disruption was conducted in the presence of excess detergent, thus preventing aggregate formation of solubilized haemagglutinin, test values comparable with those of whole virus vaccines were obtained. In agreement with these results, immunization experiments revealed that whole virus and corresponding split vaccines exhibited comparable immunogenicity in guinea pigs. Additionally it could be calculated from SDS-PAGE and densitometer tracings, obtained by scanning the gels after staining with either Coomassie blue or FITC-Con A, that 90 to 95% of whole virus HA2 was recovered in Tween-ether split vaccines. On the basis of these findings we conclude that precise quantification of Tween-ether split vaccines is not possible by the SRID test alone. As aggregate formation of solubilized haemagglutinin occurs, we suggest that either a physico-chemical method including a disaggregation procedure, such as SDS treatment, or immunological evaluation of the original whole virus preparation before disruption of virions should be applied as an additional criterion for quantification of influenza Tween-ether split vaccines.
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PMID:The quantification of the haemagglutinin content of influenza whole virus and Tween-ether split vaccines. 641 43

Influenza A virus-treated human platelets were lyzed in autologous serum. Lysis required the presence of antibody and occurred predominantly through activation of the classical complement pathway. Binding of the virus followed by its elution at 37 degrees C resulted in a dose-dependent desialation of the cells with a maximal release of 45% of total platelet sialic acid. In contrast, platelets that had been treated with Vibrio cholerae neuraminidase and from which 55% of total sialic acid had been removed were not lyzed in autologous serum and did not bind C3 as shown in binding assays using radiolabeled monoclonal anti-C3 antibody. Thus, the immune-mediated lysis of virus-treated platelets in autologous serum did not involve neoantigens expressed by desialated cells. To assess the effect of viruses on the platelet surface, treated platelets were incubated with galactose oxidase and sodium [3H]borohydride prior to separation and analysis of the labeled glycoproteins by SDS-PAGE. Viral treatment resulted in a desialation of each of the surface glycoproteins. At the same time, a labeled component of Mr 72,000 (nonreduced) and Mr 55,000 (reduced) was observed that was not present when V. cholerae-desialated platelets were examined in the same way. Immunoblotting experiments performed using antiwhole virus and anti-hemagglutinin antibodies demonstrated this component to be viral hemagglutinin. Involvement of membrane-bound hemagglutinin in antibody and in complement-mediated lysis of virus-treated platelets in autologous serum was supported by the increased lytic activity of a postvaccinal serum containing an elevated titer of complement fixing anti-hemagglutinin antibodies. Binding of a viral protein to the platelet surface provides a model for immune thrombocytopenias occurring during acute viral infections at the time of the specific immune response.
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PMID:Membrane-bound hemagglutinin mediates antibody and complement-dependent lysis of influenza virus-treated human platelets in autologous serum. 647 Jan 49

MDCK cells were infected with six human influenza C virus strains (isolated between 1947 and 1981) and seven pig influenza C virus strains (isolated in 1981 and 1982) and the virus-specific polypeptides were compared by SDS-polyacrylamide gel electrophoresis and one-dimensional peptide mapping. The major structural polypeptides, i.e. glycoprotein (gp88), nucleoprotein (NP), and membrane protein (M), and one non-structural polypeptide were identified in all strains by radiolabelling infected cells with [35S]methionine. No differences in the electrophoretic migration of the M proteins or NS proteins were observed. The two earliest human isolates, C/Taylor/1233/47 and C/Great Lakes/1167/54, had faster migrating NP proteins, and another human strain, C/Georgia/1/69, displayed a faster migrating gp88. Minor differences in the one-dimensional peptide maps produced by partial digestion of the M proteins with V8 protease were observed between the human and pig isolates, while more marked differences were noted in the peptide maps of the glycoproteins of the C/Georgia/1/69, C/Yamagata/10/81 and C/Yamagata/11/81 viruses compared to the other human strains and the pig strains. The overall conclusion is that the proteins of human influenza C viruses isolated over a 35 year period and those of recent pig influenza C virus isolates are highly conserved.
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PMID:Polypeptide synthesis in MDCK cells infected with human and pig influenza C viruses. 650 39

The proteins from cells infected with influenza A virus field isolates were labeled with [35S]methionine and analyzed by SDS-polyacrylamide gel electrophoresis. By screening more than 100 field isolates, it was found that the NS1 proteins had the greatest mobility differences, far exceeding those observed among other corresponding viral polypeptides. Partial sequence determination of RNA segment eight from 12 viruses revealed the existence of nonsense mutations at six different positions in their NS1 coding regions. The termination codons consisted of opal, ochre, and amber mutations. The sizes predicted from these sequences of 202, 217, 219, 220, 230, and 237 amino acids were in agreement with the observed mobilities of the viral polypeptides on SDS-polyacrylamide gels. The observation of large deletions in the carboxy termini of the NS1 proteins of field virus isolates would suggest that a high degree of variation can be tolerated in this polypeptide without affecting its functional capability.
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PMID:Nonsense mutations affecting the lengths of the NS1 nonstructural proteins of influenza A virus isolates. 661 93

The major structural polypeptides (gp88, NP and M) of seven different influenza C virus strains isolated between 1947 and 1981 in U.S.A. and Japan were compared by SDS-polyacrylamide gel electrophoresis and one-dimensional mapping of the peptide fragments produced after limited proteolysis with various proteases. Of the three polypeptides analysed, the membrane (M) protein appeared to be the most highly conserved since the electrophoretic mobility as well as the mapping pattern of this protein was found to be identical among all seven strains. The structure of nucleoprotein (NP) was also found to be highly conserved. The proteins of five isolates from 1964 to 1981 showed migration rates and mapping patterns indistinguishable from each other though they were slightly different in mapping patterns from the earlier isolates, C/Taylor/1233/47 and C/JJ/50. The similarities between influenza C strains were also evident with the surface glycoprotein, gp88. The gp88 proteins of the five strains isolated in 1947, 1950, 1971 and 1981 were virtually identical in migration rates as well as in mapping patterns, while the two isolates of 1964 and 1974 showed minor differences. These results strongly suggest that the surface glycoprotein of influenza C virus is structurally much more stable than the haemagglutinin and neuraminidase glycoproteins of influenza A and B viruses. Further, the findings that differences from the original influenza C strain, Taylor/1233/47 were detectable in the strains isolated in 1964 and 1974 but not in the strains isolated in 1971 and 1981 suggest that unlike the antigenic drift of types A and B influenza viruses, the structural variation of gp88 may not be a sequential event.
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PMID:Analyses of structural polypeptides of seven different isolates of influenza C virus. 682 47

The hemagglutinin of an influenza virus isolated from a wild duck (Pintail, Anas acuta) in the USSR in 1976 had been found to be antigenically indistinguishable from the hemagglutinin of H2N2 viruses of human origin isolated in 1957. The hemagglutinins from viral preparations of the A/Anas acuta/Primorie/695/76 (H2Nav2) and A/Singapore/1/57 (H2N2) strains were purified by SDS gel chromatography as the subunits HA1 and HA2. Comparison of amino acid compositions and peptide maps of tryptic peptides containing [14C]-carboxymethylcysteine showed a striking degree of similarity between the H2 hemagglutinins.
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PMID:Comparative study of influenza virus H2 (Asian) hemagglutinins isolated from human and avian sources. 719 63

The most abundant protein within the influenza virus particles is membrane protein (M protein) which forms an inner virus membrane under a lipid bilayer and plays the role of mediator during the process of assembly of a virus particle on plasma membranes. Ehrlich ascites tumor cells (EAT) when infected with influenza virus, strain WSN, produced virus-like particles containing greatly reduced amounts of M protein. Such particles were extremely fragile and easily lost hemagglutinins. The loss of this glycoprotein was accompanied by a decrease in infectious activity. SDS-PAGE analysis of RNA duplexes formed after hybridization of intracellular labeled mRNAs and unlabeled virion RNA showed that the mRNA for M protein was synthesized in EAT nearly in the same amounts as in productively infected chicken fibroblasts. Accordingly, M protein was readily revealed when the polypeptides of infected EAT were analyzed by SDS-PAGE. Thus, the reduced amount of M protein in virus particles was likely not due to the decrease in its synthesis but rather to its defective structure or to its defective transport and misintegration into plasma membranes of EAT.
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PMID:Influenza virus assembly and its defects. 721 45


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