[Sedimentation characteristics of the virions and subviral particles of influenza C viruses].

Investigation of sedimentation and some other properties of subviral particles and native virions of influenza C viruses was carried out in comparison with influenza A virions. Sedimentation rate of influenza C viruses was found to be 0.6 of that of influenza A viruses, the optical density peak coincided with the peaks of hemagglutinating and infectious activities of both influenza A and influenza C viruses. Studies with 4 influenza C virus strains isolated in different years revealed no differences in their sedimentation rates and the curve pattern. Electron microscopic, electrophoretic, and sedimentation analyses showed higher fragility of influenza C virions than those of influenza A virus, and their trend to self-disintegration. Our data showed significant differences in the effect of proteases on influenza A and C viruses. With due regard to these differences, we modified the method satisfactorily used for production of influenza A subviral particles. Some properties of subviral particles of influenza C virus were studied.