Neuraminidase activity of influenza virus-infected cells: localization and properties.

Infection of chick embryo cell (CEC) cultures with influenza virus results in the appearance of neuraminidase activity lost by the cells as a result of cultivation. Neuraminidase activity is associated mainly with the lysomal cell fraction. Different distribution of neuraminidase activity in lysosomes with various densities, different reaction to sodium ethylene diamine tetracetate (EDTA) and differenct optimal pH suggest that at early stages of viral infection the cell enzyme is activated and by the 7th hour of infection viral neuraminidase is synthesized.