G. L. Stewart et al. (New Engl. J. Med. 276: 554, 1967) described the discovery of rubella hemagglutinin (HA) and recommended that it be stored at -70 C. Subsequently, it was reported (Halonen et al., Proc. Soc. Exptl. Biol. Med. 125:162, 1967) that alkali-extracted HA antigen is stable for several weeks at 4 C and -70 C and overnight at 36 C. Before attempting to produce rubella HA antigen in ...

Many viruses evolve rapidly. For example, hemagglutinin of the H3N2 influenza A virus evolves to escape antibody binding. This evolution of the H3N2 virus means that people who have previously been exposed to an influenza strain may be infected by a newly emerged virus. In this paper, we use Shannon entropy and relative entropy to measure the diversity and selection pressure by antibody in each...

The attachment of the hemagglutinin protein of the H1N1 subtype of the pandemic influenza A virus to the sialic acid receptor Sia(α2-6)Gal has contributed to the ability of the virus to replicate in the human body and transmit among humans. In view of the pandemic caused by the replication and transmission of the H1N1 virus, more studies on the specificity of hemagglutinin towards sialic acid a...

Since the emergence of human H3N2 influenza A viruses in the pandemic of 1968, these viruses have become established as strains of moderate severity. A decline in virulence has been accompanied by glycan accumulation on the hemagglutinin globular head, and hemagglutinin receptor binding has changed from recognition of a broad spectrum of glycan receptors to a narrower spectrum. The relationship...

Influenza A virus subtype H5N1 is highly contagious among birds, causing high mortality among domestic poultry. The viral genome is contained on eight single RNA strands of which HA encode the antigenic glycoprotein called hemagglutinin. Hemagglutinin found on the surface of the influenza viruses and is responsible for binding the virus to the cell that is being infected. Among the most prevale...

A method is described for the isolation of a phytohemagglutinin from the meadow mushroom, Agaricus campestris. This protein was homogeneous by ultracentrifugation, cellulose acetate electrophoresis, and immunoelectrophoresis. The molecular weight as measured by sedimentation equilibrium was 64,000 and the sedimentation constant, szo,W = 4.8, was independent of protein concentration. There were ...

The antigenic sites on the hemagglutinin of X-31 (H3) influenza virus have been defined by using a competitive radioimmunoassay with a panel of monoclonal antibodies which includes those known to select variants with substitutions of particular amino acids. The capacity of each monoclonal antibody to block the binding of other radioiodinated monoclones to purified hemagglutinin permitted classi...

Broadly neutralizing antibodies developed from the IGHV1-69 germline gene are known to bind to the stem region of hemagglutinin in diverse influenza viruses but the sequence determinants for the antigen recognition, including neutralization potency and binding affinity, are not clearly understood. Such understanding could inform designs of synthetic antibody libraries targeting the stem epitope...

Newcastle disease virus isolates from chickens in eastern Uganda in 2001 were found to be velogenic by fusion protein cleavage site sequence analysis and biological characterization; the intracerebral pathogenicity index was 1.8. Analysis of their hemagglutinin-neuraminidase protein gene sequences revealed a novel genotype unrelated to those that caused previous outbreaks.