STRUCTURAL CONSTITUENTS OF VENEZUELAN EQUINE ENCEPHALITIS VIRUS

In potassium tartrate density gradients of concentrated Venezuelan equine encephalitis virus bands were observed which could be correlated to complete (buoyant density ρ=1.20 g/ml), incomplete (ρ = 1.17 g/ml) and partially disrupted (ρ=1.24g/ml) virus, on account of the distribution of infectivity, hemagglutinating, hemolysing, and precipitating antigens, and of electron microscopical observations. Treatment of complete, incomplete and partially disrupted virus with Tween 80 and ether resulted in release of hemagglutinating entities with a uniform density of 1.23 g/ml, serologically indistinguishable from each other. An additional maximum of hemagglutinating activity appeared at a density of 1.27 g/ml in treated complete virus that was absent in incomplete and less pronounced in partially disrupted virus after treatment. In gel double diffusion experiments with the above mentioned virus preparations two types of lines were detected; they were correlated to surface and internal antigens, respectively, of the virus particles. Electron microscopy of purified hemagglutinating material (ρ=1.23g/ml) of complete virus treated with Tween 80 and ether revealed ringlike or looped structures. © 1969 Springer-Verlag.