title: Natural heterogeneity of shape, infectivity and protein composition in an influenza A (H3N2) virus preparation.
abstract: Influenza A (X31) virus was purified over a zonal sucrose gradient. The resulting gradient fractions were examined by electron microscopy, HA and infectivity titrations and gel electrophoresis. The fractions containing a homogeneous suspension of spherical particles had the highest infectivity per amount of viral protein and a much higher HA:M ratio than the unfractionated preparation. These results explain differences in the proportions of HA and M protein we have reported elsewhere on monodisperse virus suspensions compared with earlier measurements on crude suspensions.
mesh_terms: D000818:Animals; D002501:Centrifugation, Zonal; D002642:Chick Embryo; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000032:analysis; D053122:Influenza A Virus, H3N2 Subtype; D009980:Influenza A virus / Q000032:analysis* / Q000302:isolation & purification / Q000472:pathogenicity / Q000648:ultrastructure; D008854:Microscopy, Electron; D014763:Viral Matrix Proteins; D014764:Viral Proteins / Q000032:analysis*
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D014763:Viral Matrix Proteins; D014764:Viral Proteins