Supplementation of Sugar Analogues in Rice Cell Cultures for the Elimination of Plant-specific Nglycans of Acid α-glucosidase

초록

N-glycosylation is one of the complex post translational modifications in eukaryotes. Many biopharmaceuticals in markets are glycoproteins. Plant cell culture is known to be an alternative system for the production of biopharmaceutical glycoproteins. But plants express plant-specific N-glycan residues (α1,3-fucose, β1,2-xylose) which have potential immunogenicity to humans. 2-Deoxy-2-fluoro-L-fucose (2F-Fuc) and 3-deoxy-3-fluoro-Dxylose (3F-Xyl) are fluorinated sugar analogues and potent inhibitors to fucosyltransferase (FucT) and xylosyltransferase (XylT). In this study, acid α-glucosidase (GAA) expressed in transgenic rice cells were used as a target protein for reducing plant-specific N-glycans. Three different concentrations of (5, 50, 100 μM) 2F-Fuc and 3F-Xyl were supplemented to culture medium for the elimination of core-fucose and xylose residues. Toxic effects on cell growth as well as viability were not shown during cell cultures. Composition of GnGnXF (GlcNAc2Man3XylFucGlcNAc2) structure was decreased from 36% to 20% under 50 and 100 μM 2F-Fuctreated conditions. However, 3F-Xyl showed no effects on XylT. In conclusion, it was found that 2F-fuc could be used as an inhibitor to FucT during plant cell cultures for reducing immunogenicity.