Structures of the N-linked carbohydrate of ascorbic acid oxidase from zucchini.
The N-glycan moiety of ascorbic acid oxidase from zucchini (Cucurbita pepo) has been described to be a core-pentasaccharide with a xylose [D'Andrea et al. (1988) Glycoconjugate J 5:151-7]. Ascorbic acid oxidase is sometimes used to characterize antibodies directed against carbohydrate determinants on plant glycoproteins. To prevent misinterpretations of immunological data, the structure of the N-glycan of ascorbic acid oxidase has been reinvestigated. The oligosaccharides were released by almond N-glycosidase and analysed as their pyridylamino derivatives by 2D-HPLC and exoglycosidase digestions. The main structure resembled the typical complex plant N-glycan consisting of a core-pentasaccharide decorated with xylose and 3-linked fucose. The other abundant species lacked the fucose residue. Small amounts of these glycans carried a GlcNAc residue on the 6-arm. Therefore, ascorbic acid oxidase will not only react with antibodies directed against the xylosylated region but also with those binding to N-glycans with 3-linked fucose.
Altmann
F
F
Institut für Chemie, Universität für Bodenkultur, Wien, Austria.
D001204:Ascorbate Oxidase / Q000737:chemistry*; D002240:Carbohydrate Sequence; D019662:Cucurbitaceae / Q000201:enzymology*; D006023:Glycoproteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry
D006023:Glycoproteins; D010940:Plant Proteins; D011134:Polysaccharides; D001204:Ascorbate Oxidase