Characterization of common carbohydrate antigenic determinants on soya bean cell-wall enzymes

Three soya-bean (Glycine max) cell-wall enzymes (β-glucosidase, pectin methyl esterase and phosphatase) have been found to be glycoproteins. The polyclonal antibodies raised against pectin methyl esterase and β-glucosidase lacked specificity, cross-reacted highly with native enzymes and also both reacted with pure soya-bean phosphatase, horseradish peroxidase and honeybee venom phospholipase A2. They did not react with either non-glycosylated bacterial phosphatase or deglycosylated cell-wall enzymes. The two antisera contained both non-specific anti-glycan antibodies and specific anti-polypeptide antibodies that were quantified. Antiglycan antibodies specific to α1–3 fucose and β1–2 xylose were detected in both antisera and were separated and quantified. The occurrence of terminal fucose (and mannose) was confirmed with specific lectins. These results indicate that most of the common glycan epitopes probably correspond to the asparagine-linked complex glycan previously detected in several glycoproteins of plants as well as in those of molluscs and insects.