Preliminary investigation of the structure of the carbohydrate component of Vicia graminea lectin, a plant glycoprotein

Abstract

Purified Vicia graminea lectin, isolated from seeds, was found to contain D-mannose, 2-acetamido-2-deoxy-D-glucose, L-fucose, D-galactose, and D-xylose in the molar ratios approximately 3.9:1.5:1.2:1.1:1.0. The oligosaccharides, obtained after hydrazinolysis of Vg-lectin, were N-reacetylated, reduced with sodium borohydride, and fractionated into two peaks. The first peak contained D-galactose, D-mannose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-glucitol in the molar ratios 6:3:2:0.7. After h.p.l.c. fractionation into five oligosaccharides, the second peak contained D-mannose, D-xylose, L-fucose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-glucitol. Methylation analysis suggested the following general structure for these oligosaccharides: (formula; see text).