Isolation of the dengue virus envelope glycoprotein from membranes of infected cells by concanavalin A affinity chromatography

Abstract

The membranes isolated from type 2 dengue virus-infected BHK[baby hamster kidney]-21/15 cells contain 3 glycosylated virus-specified proteins; 1 corresponds to the virion envelope glycoprotein V-3, and the other 2 are nonstructural virus-specified proteins NV-2 and NV-3. A combination of 2 nonionic detergents, Nonidet P-40 and Triton X-305, solubilized .gtoreq. 80% of the membrane-bound protein and the majority of the type 2 dengue virus complement-fixing antigens. The soluble material was adsorbed by concanavalin A-Sepharose in the presence of the nonionic detergents, which were subsequently removed by washing with deoxycholate-containing buffer. The bound glycoprotein was eluted by the addition of .alpha.-methyl glucopyranoside. V-3 was the only virus-specified protein in the .alpha.-methyl glucopyranoside eluate. The V-3-containing fraction did not cross-react with antisera against other selected Flaviviruses in the complement fixation test. The V-3 contained in the isolated fraction differed from the parent membrane-bound V-3 in 2 interesting, and as yet unexplained, ways: it exhibited hemagglutinating activity similar to that of the infectious virus, but it did not block the action of neutralizing antibody.