Structure of asparagine-linked sugar chains in the major polypeptide of hepatitis B surface antigen

Asparagine-linked sugar chains were quantitatively released from hepatitis B surface antigen on hydrazinolysis followed by N-acetylation and NaB3H4 reduction. The released oligosaccharides were composed of two major sialylated components and a trace of a neutral component. From the results of the combination of sequential exoglycosidase digestion and methylation analysis, the structures of the acidic and the neutral components were deduced to be NeuAc alpha 2----6Gal beta 1----4GlcNAc beta 1----2Man alpha 1----3(+/- NeuAc alpha 2----6Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6)Man beta 1----4GlcNAc beta 1----4GlcNAcOT and Gal beta 1----4GlcNAc beta 1----2Man alpha 1----3(Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6)Man beta 1----4GlcNAc beta 1----4GlcNAcOT, respectively.