One extra oligosaccharide chain of the high-mannose class in the E2 protein of a Sindbis virus isolate

The number and nature of oligosaccharide chains in the E2 envelope protein (and its precursor PE2) from two strains of Sindbis virus, originally derived from the same HR strain, were investigated. The E2 glycoproteins (and the PE2 proteins) of the two strains had different electrophoretic mobilities on a sodium dodecyl sulfate-polyacrylamide gel. We observed that the glycopeptides from the E2 protein of one of the two strains included an extra oligosaccharide chain of the mannose-rich type. The altered pattern of glycosylation does not interfere with the intracellular migration of the protein and the envelopment and budding of the virus.