Glycoform analysis of N-glycans linked to glycoproteins expressed in rice culture cells: predominant occurrence of complex type N-glycans.
Although it has been found that plant endo-beta-N-acetylglucosaminidase shows strong activity towards denatured glycoproteins and glycopeptides with high-mannose type N-glycans and free high-mannose type N-glycans bearing the chitobiosyl unit, the endogenous substrates for plant endoglycosidase have not yet been identified. Recently we purified and characterized an endo-beta-N-acetylglucosaminidase from rice culture cells and identified the gene encoded. Furthermore, we found structural features of free N-glycans in the cells, indicating that high-mannose type species (Man(9-5)GlcNAc(1)) occur at concentration of several micromolar (microM). Hence, in this study we analyzed glycoform of N-glycans linked to glycoproteins expressed in rice culture cells to see whether endogenous glycoproteinous substrate occurs in reasonable amounts. Structural analysis revealed that more than 95% of total N-glycans linked to glycoproteins in the rice cells had the plant complex type structure, including Lewis a epitope-harboring type, although high-mannose type structures account for less than 5% of total N-glycans.
Maeda
Megumi
M
Division of Bioscience, Department of Biofunctional Chemistry, Graduate School of Natural Science and Technology, Okayama University.
Kimura
Yoshinobu
Y
D002236:Carbohydrate Conformation; D002460:Cell Line; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D003208:Concanavalin A / Q000494:pharmacology; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism; D012275:Oryza / Q000166:cytology* / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
D006023:Glycoproteins; D011134:Polysaccharides; D003208:Concanavalin A; D006026:Glycoside Hydrolases