Structural analysis on the sugar chains ofα1-antitrypsin from patients with hepatocellular carcinoma

Abstract

Abstract Chemical structures of the sugar chains ofα1-antitrypsin (AAT) from patients with hepatocellular carcinoma (HCC) with different affinity forLens culinaris agglutinin (LCA) were examined by pyridylamination of their oligosaccharides and stepwise exoglycosidase digestion. By using reversed-phase and size-fractionation high-performance liquid chromatography systems we confirmed that the LCA-reactive species of AAT from patients with HCC contained a biantennary sugar chain with a fucose residue at the innermost N-acetylglucosamine residue, Galβ1-4GlcNAβ1-2Manα1-6(Galβ1-4GlcNAcβ1-2Manα1-3)Manβ1-4GlcNAcβ1-4(Fucα1-6)GlcNAc, as a major component, and a biantennary sugar chain without a fucose residue, Galβ1-4GlcNAcβ1- 2Manα1-6(Galβ1-4GlcNAβ1-2Manα1-3)Manβ1-4G1cNAcβ1-4GlcNAc, as a minor component. Thus, present results indicate that a characteristic feature of the carbohydrate chains of AAT from patients with HCC is an increment in fucosylation.