Large-Scale Preparation of Asn-Glycopeptide Carrying Structurally Homologous Antigenic N-Glycan

In our previous report (M. Okano, et al., Clin. Exp. Allergy, 34, 770-778 (2004)), we found that free plant complex type N-glycans suppressed the production of IL4 from Th2 cells of Japanese cedar pollinosis patients, suggesting that plant complex type N-glycan can be used as a leading compound for developing immuno-pharmaceuticals. Although immunoreactive plant complex type N-glycans occur ubiquitously on glycoproteins expressed in plants, an appropriate procedure has not been established to prepare non-labeled immunoreactive glycans or glycopeptides bearing structurally homologous immunoreactive glycans in large amounts. In this study, therefore, we developed a new preparative procedure for the large-scale preparation of Asn-glycopeptide bearing plant complex type N-glycan using a combination of gel-filtration and the hydrophilic partitioning method. By this new method, about 103 mg of Asn-glycopeptide bearing the antigenic N-glycans was obtained from 1.9 kg of shelled Ginkgo biloba seeds.