Density gradient characterization of disrupted and untreated eastern encephalitis virus.

Abstract

Preparations of eastern encephalitis virus were disrupted by treatment with sodium deoxycholate. Tween 80 and ether, and sodium lauryl sulfate. The effect of these treatments on the viral specific activities of eastern encephalitis virus were studied. Untreated and disrupted preparations of eastern encephalitis virus were physically characterized by buoyant density centrifugation in cesium chloride density gradients and by rate zonal sedimentation in sucrose density gradients. Disruption by both sodium deoxycholate and Tween 80-ether resulted in the release of hemagglutinating subunits of higher density than the hemagglutinin associated with the intact virion. The hemagglutinating subunits released by both treatments were similar in density and size. A dense complement-fixing component, believed to represent released viral nucleoprotein core, was detected in cesium chloride gradients after sodium deoxycholate treatment of the virus. It was not detected in untreated preparations or in preparations treated with Tween 80-ether. Even at low concentrations, sodium lauryl sulfate was destructive of all viral activities save complement-fixation activity. The hemolytic activity of eastern encephalitis virus was physically closely associated with infectivity and hemagglutinating activity of the virus and was apparently dependent on the structural integrity of the virion.