%0 Journal Article %A Reginster, Monique %A Joassin, Luc %A Fontaine-Delcambe, Patricia %T Ligands for Antibody to M-Protein are Exposed at the Surface of Influenza Virions: Effect of Proteolytic Treatment on their Activity %D 1979 %J Journal of General Virology, %V 45 %N 2 %P 283-289 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-45-2-283 %I Microbiology Society, %X SUMMARY 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. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-45-2-283