The carbohydrate chains of influenza virus hemagglutinin

The major surface antigen of influenza virus A/Leningrad/385/80 (H3N2), H3 hemagglutinin, as well as its heavy and light subunits were obtained by bromelain treatment, followed by gel chromatography. Carbohydrate chains were split off from both subunits by lithium borohydride-lithium hydroxide in aqueous 2-methyl-2-propanol, and individual oligosaccharides isolated. The main oligosaccharides, whose structure was determined by 1H-n.m.r. spectroscopy and chemical methods, are of the ordinary oligomannoside and complex types. It was found that, in spite of the great difference in number of glycosylation sites in heavy and light subunits, the amount and even relative abundance of variants of carbohydrate chains in both subunits are very similar.