Physicochemical characteristics of a vaccinal strain of the Leningrad-3 mumps virus (L-3)

Purified virions of the vaccine strain Leningrad-3 of mumps virus propagated in Japanese quail embryo cell cultures had a buoyant density 1.18-1.19 g/ml in sucrose gradient, contained 50 S RNA and showed variable sizes in electron microscopy as manifested by heterogeneity of the virus zone in sedimentation analysis. Purified L-3 virus contained 5 major polypeptides with molecular weights of 74,000, 68,000, 58,000, 45,000, and 39,000 daltons. Each polypeptide had an individual oligopeptide composition.