Title : Structural analysis on
the sugar chains of human
alpha 1-antitrypsin : presence of
fucosylated biantennary glycan in hepatocellular carcinoma
Abstract :
- Chemical structures of the sugar chains of alpha 1-antitrypsin ( AAT ) from patients with hepatocellular carcinoma (HCC) and from healthy individuals with a different affinity for Lens culinaris agglutinin ( LCA ) were examined by pyridylamination of their oligosaccharides and stepwise exoglycosidase digestion in combination with reversed-phase and size-fractionation high-performance liquid chromatography
- We found that the LCA-reactive species of AAT from patients with HCC carried both the biantennary sugar chain with a fucose residue at the innermost N-acetylglucosamine residue, Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc-PA, and the biantennary chain residue at the innermost N-acetylglucosamine residue, Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc-PA, and the biantennary chain without a fucose residue, Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc-PA, at a ratio of about 1:0.6
- The LCA-nonreactive species of AAT contained the biantennary sugar chain Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc as a major component
- These results indicate that a characteristic feature of the carbohydrate chains of AAT from patients with HCC is an increment in fucosylation