RESUMO
Fucosyl glycoasparagines accumulating in the urine of a patient with fucosidosis were isolated using reverse-phase HPLC. Structural analysis of 25 glycoasparagines was carried out by combination of methylation and 400-MHz 1H-NMR spectroscopy analyses. The compounds represent different steps in the incomplete catabolism of N-glycosidically linked glycans, as the result of an alpha-L-fucosidase deficiency. All of the glycoasparagines possess a fucose residue alpha-1,6-linked to the GlcNAc 1 residue attached to asparagine. Fucose residues on the peripheral branches were linked either alpha-1,3 to GlcNAc residues (X determinant) or alpha-1,2 to galactose residues (H determinant). The present study allows precise assignments of the NMR parameters for most of the fucosyl linkages occurring in N-glycosidically linked glycans of the N-acetyllactosamine type.
Assuntos
Fucose/urina , Fucosidose/urina , Glicopeptídeos/urina , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Fucose/análogos & derivados , Glicopeptídeos/química , Humanos , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência MolecularRESUMO
Neutral and acidic oligosaccharides derived from human meconium glycoproteins by alkaline borohydride degradation have been separated by high-performance liquid chromatography on a Micro-Pak anion-exchange column. In each class, oligosaccharides were purified by normal-phase (neutral and acidic oligosaccharides) and reversed-phase (neutral oligosaccharides) chromatography. Effective separations of neutral oligosaccharides and acidic oligosaccharides were achieved.