Small complex-type N-linked glycans are attached to cell-wall bound exo-beta-glucanases of both mung bean and barley seedlings.

N-linked glycans of wall-bound exo-beta-glucanases from mung bean and barley seedlings, namely Mung-ExoI and Barley-ExoII, were characterized. The N-linked glycans of Mung-ExoI and Barley-ExoII were liberated by gas-phase hydrazinolysis followed by re-N-acetylation. Their structures were determined by two-dimensional sugar-mapping analysis and MALDI-TOF mass spectrometry. N-glycans from both glucanases were of paucimannosidic-type (small complex-type) structures, Manalpha1-6(+/-Manalpha1-3)(Xylbeta1-2)Manbeta1-4GlcNAcbeta1-4(+/-Fucalpha1-3) GlcNAc, which are known as typical vacuole-type N-glycans. The results suggest that N-glycans of cell-wall glucanase were produced by partial trimming of complex-type N-glycans by exoglycosidases during its transport from Golgi apparatus to cell walls or in the cell walls.