Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: The carbohydrate contents of coronavirus glycoproteins El and E2 have been analyzed. E2 has complex and mannose-rich-type oligosaccharide side-chains, which are attached by N-glycosidic linkages to the polypeptide. Glycosylation of E2 is initiated at the co-translational level, and it is inhibited by tunicamycin, 2deoxy-glucose, and 2-deoxy-2-fluoro-glucose. Thus, E2 belongs to a glycoprotein type found in many other enveloped viruses. El, in contrast, represents a different class of glycoprotein. The following observations indicate that its carbohydrate side-chains have O-glycosidir linkage. (1) The constituent sugars of El are ,Vacrtylglucosamine, N-acet,ylgalactosamine, galactose, and neuraminic acid : mannose and fucose are absent. (2) The side-chains can be removed by ,!elimination. (3) Glycosylation of El is not sensitive to the compounds interfering with ,Vglycosylation. El is the first viral glycoprotein analyzed that contains only O-glycosidic linkages. Coronaviruses are therefore a suitable model system to study biosynthesis and processing of this type of glycoprotein. cw,22-2~:~6/~1/~~0~93-18 ~02.00/0 Q 1981 Academic Press Inc. (London) Ltd.

Coronavirus Glycoprotein El, a New Type of Viral Glycoprotein