title: Impairment of the M-protein and unmasking of a superficial type-specific antigen by proteolytic treatment of influenza A virions with preservation of host-specific antigenicity.
abstract: Influenza PR8 particles resulting from strong treatment with caseinase C are spikeless, devoid of neuraminidase and hemagglutinin 1 and 2 glycopeptides, and contain a Schiff-negative polypeptide of about 13,000 molecular weight which exists as traces in intact virions. Their M-protein polypeptide content is reduced to 50% of its original value, but there is no evidence of particle disruption nor of lipid release. They fix complement in the presence of both anti-M-protein antiserum and antiserum raised against a host polysaccharide. During exposure to caseinase C, an antigen is unmasked. It is type-specific and its identity with the M-protein is discussed.
mesh_terms: D000956:Antigens, Viral; D003168:Complement Fixation Tests; D000939:Epitopes; D006389:Hemagglutinins, Viral; D009980:Influenza A virus / Q000187:drug effects / Q000276:immunology*; D009439:Neuraminidase; D010447:Peptide Hydrolases / Q000494:pharmacology*; D014764:Viral Proteins
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D006389:Hemagglutinins, Viral; D014764:Viral Proteins; D009439:Neuraminidase; D010447:Peptide Hydrolases