[Characteristics of isolating influenza virus hemagglutinin using purified bromelin].

Gel filtration and ion-exchange chromatography were used to isolate a fraction with the highest proteolytic activity and virtually lacking glycosidases from a commercial bromeline preparation ("Serva", grade B) showing, in addition to proteolytic, also glycosidase activity. The utilization of purified bromeline allows isolation of hemagglutinin without residual neuraminidase activity from influenza virus of various serotypes (H1, H1, and H3). The results are discussed on the basis of an assumption of analogous localization but different conformation accessibility of bromeline-sensitive parts of the light chains of influenza viruses of different subtypes, and a possible role of the carbohydrate component of surface glycoproteins, hemagglutinin and neuraminidase of influenza virus virions.