Sulfated N-linked carbohydrate chains in porcine thyroglobulin

N-linked carbohydrate chains of porcine thyroglobulin were released by the hydrazinolysis procedure. The resulting mixture of oligosaccharide-alditols was fractionated by high-voltage paper electrophoresis, the acidic fractions were further separated by high-performance liquid chromatography on Lichrosorb-NH2, and analyzed by 500-MHz 1H-NMR spectroscopy and, partially, by permethylation analysis. Of the acidic oligosaccharide-alditols, the following sulfated carbohydrate chains could be identified: NeuAcα2→6Galβ1→4GlcNAcβ1→2Manα1→3[(SO3Na→3)Galβ1→4GlcNacβ1→ 2Manα1→6]Manβ1→4GlcNAcβ1→4[Fucα1→6]GlcNAc-ol and SO3Na→6)0-1GlcNAcβ1→2Manα1→3[NeuAcα2→6Galβ1→4(SO3Na→6)1-0 GlcNAcβ1→2Manα1→6]Manβ1→4GlcNAcβ1→4[Fucα1→6]GlcNAc-ol. The sulfated structural elements for porcine thyroglobulin form novel details of N-linked carbohydrate chains. They contribute to the fine structure of these oligosaccharides and are another type of expression of microheterogeneity.