[Influenza virus hemagglutinin: hydrodynamic properties and molecular weight]

Hydrodynamic properties of hemagglutinin isolated with bromelain from influenza virus were studied. The sedimentation constant determined by the method of analytical ultracentrifugation was 9.17 +/- 0.17 S. The translation diffusion coefficient estimated by the method of optic mixing spectroscopy comprised (3.6 +/- 0.1) X 10(+7) cm2/s. A comination of both the constants in Svedberg's equation allowed calculation of the hemagglutinin molecular weight (approximately 230,000) which suggests a three-subunit structure of the molecule. The hydrodynamic diameter and friction ratio of an isolated molecule were calculated.