Growth-dependent alterations in oligomannosyl glycopeptides expressed in Sindbis virus glycoproteins

Sindbis virus was used to examine host cell growth-dependent expression of oligomannosyl glycopeptides within single species of viral glycoproteins. Four mannosyl oligosaccharides ranging from 5 to 8 mannose residues were separated on Bio-Gel P4 column chromatography. Virus derived from rapidly growing chicken embryo fibroblasts displayed greater quantities of larger sized oligomannosyl glycopeptides in intact virus and in purified Sindbis virus glycoproteins E1 and E2 compared with virus from nongrowing cells. The pattern of mannosyl oligosaccharides in the two glycoproteins differed remarkably. E1 and E2 contained predominantly Man5GlcNAc and Man7GlcNAc, respectively; in addition, E1 relative to E2 contained more complex-type glycopeptides than mannosyl-type glycopeptides. These data clearly demonstrate that host-dependent alterations in glycosylation are expressed in Sindbis virus and that differences in specific glycosylation patterns are obscured in oligosaccharides derived from mixtures of glycoproteins. It is apparent that processing of these cotranslated glycoproteins can yield different patterns of oligosaccharide structures.