title: Ligands for antibody to M-protein are exposed at the surface of influenza virions: effect of proteolytic treatment on their activity.
abstract: Antiserum to pure M-protein extracted from PR8 virions neutralized the infectivity and inhibited the haemagglutinating activity of various influenza A virions. It agglutinated concentrated suspensions of these virions and fixed complement in their presence. Antibodies to M-protein were readily absorbed by intact virions or by spikeless particles obtained after proteolytic treatment, giving clear evidence that M-protein is exposed at the surface of the virus envelope. The data suggest that when antibodies to M-protein occupy specific ligands exposed at the surface of the virion they interfere with sites critical for infectivity and haemagglutinating activity.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D001666:Binding Sites, Antibody; D001798:Blood Proteins / Q000276:immunology*; D003168:Complement Fixation Tests; D006385:Hemagglutination Inhibition Tests; D007136:Immunoglobulins; D009980:Influenza A virus / Q000187:drug effects / Q000276:immunology*; D009500:Neutralization Tests; D009975:Orthomyxoviridae / Q000276:immunology*; D010447:Peptide Hydrolases / Q000494:pharmacology; D011817:Rabbits / Q000276:immunology; D014764:Viral Proteins / Q000276:immunology*; D014771:Virion / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D001798:Blood Proteins; D007136:Immunoglobulins; C009823:M-proteins (Myeloma); D014764:Viral Proteins; D010447:Peptide Hydrolases; C023870:caseinase C