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D C Wiley

Publications and source records attributed to D C Wiley.

At least 181 records · Page 10Linked to original sources
PubMed1984

Studies on the adaptation of influenza viruses to MDCK cells.

The amino acid sequences and biological properties of the haemagglutinin of three variants of the influenza virus X-31 (H3N2) selected for their capacity to grow in MDCK cells are reported. In two variants, amino acid substitutions at HA1 residues 8 and 144 correlated with the loss of a site for glycosylation and specific changes in antigenicity, respectively. In all three variants substitution of an arginine residue for histidine at HA1 position 17 was correlated with increased pH optima of haemolysis. The importance of this substitution for cleavage of the haemagglutinin precursor required to produce infectious virus is discussed in relation to the three-dimensional structure of X-31 haemagglutinin.

Adaptation, Physiological↗
PubMed1984

Antigenic analyses of influenza virus haemagglutinins with different receptor-binding specificities.

Monoclonal antibodies were used to compare the antigenicities of the haemagglutinins of two receptor binding mutants of X-31 (H3N2) influenza virus. The mutants which differed from each other in recognizing sialic acid in either alpha 2-6 linkage or alpha 2-3 linkage to galactose also differed exclusively at residue 226 of the HA1 polypeptides of their haemagglutinins (G. N. Rogers, J. C. Paulson, R. S. Daniels, J. J. Skehel, I. A. Wilson, and D. C. Wiley, Nature (London) 304, 76-78, 1983). The results obtained indicate that whereas the majority of antihaemagglutinin monoclonal antibodies react with both mutants equally well, a number which specifically recognize residues 193, 199, 219, and 229 of HA1 of the alpha 2-6 linkage-binding mutant fail to recognize the alpha 2-3 linkage-binding haemagglutinins. The results are discussed with reference to the three-dimensional structure of the haemagglutinin and in relation to differences in antigenicity observed in the haemagglutinins of viruses grown in cells of different types.

Antibodies, Monoclonal↗
PubMed1984

A carbohydrate side chain on hemagglutinins of Hong Kong influenza viruses inhibits recognition by a monoclonal antibody.

A single amino acid substitution, Asp-63 to Asn-63, was detected in the hemagglutinin of an antigenic variant of the 1968 Hong Kong (H3) influenza virus that was selected by growth of the wild-type virus in the presence of a monoclonal antibody. The mutation generates an oligosaccharide attachment site, Asn-Cys-Thr at residues 63-65, that is glycosylated. Immunoprecipitation experiments with extracts from variant virus-infected cells prepared in the presence or absence of tunicamycin, which inhibits glycosylation, demonstrate that addition of the new oligosaccharide side chain is required to prevent reaction with the monoclonal antibody. Similar experiments with the virus of the 1969 Hong Kong influenza epidemic, A/England/878/69, which also contains a hemagglutinin glycosylated at residue 63, support this conclusion and provide evidence for the epidemiological significance of carbohydrate-mediated modifications of hemagglutinin antigenicity.

Amino Acid Sequence↗
PubMed1983

Electron microscopy of influenza haemagglutinin-monoclonal antibody complexes.

The molecular locations of antibody binding sites on the haemagglutinin of influenza virus X-31 were investigated by electron microscopy of haemagglutinin-monoclonal antibody complexes. Evidence was obtained for different sites of binding of different antibodies and direct correspondence was observed between these sites and the locations of antigenic sites A, B, and E (D. C. Wiley, I. A. Wilson, and J. J. Skehel (1981). Nature (London) 289, 373-378) defined by determining the amino acids recognized by the specific antibodies.

Amino Acids↗
PubMed1983

Sequential mutations in hemagglutinins of influenza B virus isolates: definition of antigenic domains.

Comparative analysis of the amino acid sequences of hemagglutinins (HAs) of influenza B/Lee/40, B/Md/59, and B/HK/73 viruses has allowed examination of the molecular basis of antigenic variation in type B viruses. As seen with influenza type A viruses, antigenic drift in influenza B viruses proceeds mostly through the accumulation of amino acid substitutions within the HA1 portion of the HA molecule. However, the rate of variation observed among the influenza B virus HAs appears to be significantly lower than the observed rate of variation among influenza A virus HAs. The overall rate of amino acid change in the HA1s of the influenza B viruses studied is 2% per 10 years, whereas the HA1s of H3 influenza A viruses vary by 9.2% per 10 years. The sequences of the influenza B HAs were also examined in relation to the three-dimensional model for the A/Aichi/2/68 HA. When the primary amino acid sequences are compared, it appears that most of the important structural features of the type A HAs--such as the sialic acid binding site, the disulfide linkages, and the stem structure of the trimer--are conserved in the influenza B virus HAs. Regions are also identified where extensive amino acid substitutions have occurred among the three antigenically distinct influenza B virus HAs. The locations of these areas in the B HA structure correspond to antigenic regions proposed for the A virus HAs. In addition, modulation of antigenic regions in B virus HAs may also occur through amino acid deletions and variation in glycosylation sites.

Amino Acid Sequence↗
PubMed1983

Analyses of the antigenicity of influenza haemagglutinin at the pH optimum for virus-mediated membrane fusion.

At the pH optimum for membrane fusion the haemagglutinin glycoprotein (HA) of the influenza virus membrane which is implicated in the fusion activity undergoes a conformational change. We have analysed the effects of this change on the antigenicity of the haemagglutinin by reacting the molecule with monoclonal antibodies of defined specificity. The results obtained indicate that specific changes in antigenicity occur in antigenic sites B and D and are interpreted in terms of the three-dimensional structure of the molecule and the effects of low pH incubation on it. Our results also provide evidence for the antigenic significance of amino acid sequence changes in site B of the HAs of natural isolates and allow clear delineation of this site into two regions.

Amino Acid Sequence↗
PubMed1983

Antigenic and amino acid sequence variations in the haemagglutinins of type A influenza viruses recently isolated from human subjects.

Since 1978, influenza A viruses with different antigenic properties have been isolated in many countries, even though little influenza activity has been recorded. In the present paper, the antigenic properties of viruses representative of isolates from each year since 1979 are compared, and the amino acid sequences of their haemagglutinins are described in detail. The reults give an indication of the extent and nature of variation in influenza A viruses during this period.

Amino Acid Sequence↗
PubMed1982

Changes in the conformation of influenza virus hemagglutinin at the pH optimum of virus-mediated membrane fusion.

A conformational change in the hemagglutinin glycoprotein of influenza virus has been observed to occur to pH values corresponding to those optimal for the membrane fusion activity of the virus. CD, electron microscopic, and sedimentation analyses show that, in the pH range 5.2-4.9, bromelain-solubilized hemagglutinin (BHA) aggregates as protein-protein rosettes and acquires the ability to bind both lipid vesicles and nonionic detergent. Trypsin treatment of BHA in the pH 5.0-induced conformation indicates that aggregation is a property of the BHA2 component and that the conformation change also involves BHA1. The implications of these observations for the role of the glycoprotein in membrane fusion are discussed.

Bromelains↗
PubMed1981

Structure of the haemagglutinin membrane glycoprotein of influenza virus at 3 A resolution.

The haemagglutinin glycoprotein of influenza virus is a trimer comprising two structurally distinct regions: a triple-stranded coiled-coil of alpha-helices extends 76 A from the membrane and a globular region of antiparallel beta-sheet, which contains the receptor binding site and the variable antigenic determinants, is positioned on top of this stem. Each subunit has an unusual loop-like topology, starting at the membrane, extending 135 A distally and folding back to enter the membrane.

Binding Sites↗
PubMed1980

Studies on the structure of the haemagglutinin.

The biosynthesis of the haemagglutinin glycoproteins of infectious influenza virus particles involves proteolytic cleavage of the primary translation products and the amino acid sequences at the two sites of processing are presented. In addition, details of the primary structure of the haemagglutinin of A/Japan/305/57 (H2N1) are reported and compared with information available for haemagglutinins of other subtypes.

Amino Acid Sequence↗