Abstract
The oligosaccharides of the structural glycoprotein (VP7) of calf rotavirus were characterized. The precursor of VP7 produced in infected cells in the presence of tunicamycin migrated on SDS-polyacrylamide gels with an apparent molecular weight 6000 less than the glycosylated glycoprotein. Endoglycosidase (Endo) H digestion of the mature virus resulted in a decrease of 5000 in the molecular weight of VP7 in two discrete stages. Analysis of Endo H-treated, 3H-labelled digestion products of VP7 on Bio-Gel P-4 identified an oligosaccharide of molecular weight 1350 as the predominant form. Further treatment of the digest with mannosidase and analysis on Bio-Gel P-2 columns indicated that the oligosaccharide was digested into a free mannose and an oligosaccharide of molecular weight 400 in the ratio of 6:1. This indicates that the oligosaccharides of VP7 consist of four N-linked (Man)7 residues, two of which occupy more exposed and two more cryptic positions in the VP7 molecule.