Localization of a neutralizing epitope on the envelope protein of dengue virus type 2.

Two neutralization-resistant variants of dengue virus type 2 were selected using the neutralizing monoclonal antibody G8D11. Virus N-GV4 was derived from the New Guinea C strain and virus P-GV3 from the PUO-218 strain. Both variants had an identical change at nucleotide 919 in the E gene, causing a substitution of glutamic acid for lysine at residue 307 in the E glycoprotein. The substitution abolished the ability of antibody G8D11 to bind to the E glycoprotein in radioimmunoprecipitation experiments. The epitope was sensitive to treatment with SDS and was dependent on the formation of a disulfide bridge. This dependency was determined by mutagenesis of Cys residues 11 and 12 in the E glycoprotein.