Antigenic Characterization of Two Sindbis Envelope Glycoproteins Separated by Isoelectric Focusing.

摘要

The isoelectric point of intact Sindbis virus was determined to be pI 4.2 using isoelectric focusing in sucrose gradients. Following non-ionic detergent disruption and subsequent electrofocusing, three structural proteins were separated. The two envelope glycoproteins (E1 and E2) were resolved at isoelectric points 6 and pI 9, respectively, and nucleocapsid protein was localized toward the anode at approximately pH 3. The pI 6 protein appeared to be the only virus hemagglutinin while both pI 6 and pI 9 proteins were antigenic in complement fixation and radioimmune precipitation tests. The pI 6 (E1) protein cross-reacted with antisera to the closely related western equine encephalitis virus. In contrast, the pI 9 (E2) protein antigen appeared Sindbis virus specific. Only antiserum prepared to the pI 9 protein antigen neutralized infectious Sindbis virus. (Author)