Influenza virus proteins: identity, synthesis, and modification analyzed by two-dimensional gel electrophoresis

A modification of the two-dimensional protein electrophoresis system of O'Farrell was used to resolve influenza A virus proteins from each other and from host proteins in infected cells. Viral protein spots corresponding to the hemagglutinin proteins, neuraminidase, nucleocapsid protein, and nonstructural protein, were identified on the two-dimensional electrophoretogram. Use of the two-dimensional separation has allowed us to identify glycoprotein heterogeneity, to demonstrate directly the synthesis of neuraminidase, to analyze some viral proteins early after infection, and to demonstrate that the influenza virus NP and NS proteins are phosphorylated in infected MDCK cells.