title: N-linked oligosaccharides of glycoproteins from Ginkgo biloba pollen, an allergenic pollen.
abstract: The pollen of Ginkgo biloba is one of the allergens that cause pollen allergy symptoms. The plant complex type N-glycans bearing beta1-2 xylose and/or alpha1-3 fucose residue(s) linked to glycoallergens have been considered to be critical epitopes in various immune reactions. In this report, the structures of N-glycans of total glycoproteins prepared from Ginkgo biloba pollens were analyzed to confirm whether such plant complex type N-glycans occur in the pollen glycoproteins. The glycoproteins were extracted by SDS-Tris buffer. N-Glycans liberated from the pollen glycoprotein mixture by hydrazinolysis were labeled with 2-aminopyridine and the resulting pyridylaminated (PA-)N-glycans were purified by a combination of size-fractionation HPLC and reversed-phase HPLC. The structures of the PA-sugar chains were analyzed by a combination of two-dimensional sugar chain mapping, IS-MS, and MS/MS. The plant complex type structures (GlcNAc2Man3Xyl1Fuc1GlcNAc2 (31%), GlcNAc2Man3Xyl1GlcNAc2 (5%), Man3Xyl1Fuc1GlcNAc2 (13%), GlcNAc1Man3Xyl1Fuc1GlcNAc2 (8%), and GlcNAc1Man3Xyl1GlcNAc2 (17%)) have been found among the N-glycans of the glycoproteins of Ginkgo biloba pollen, which might be candidates for the epitopes involved in Ginkgo pollen allergy. The remaining 26% of the total pollen N-glycans have the typical high-mannose type structures: Man8GlcNAc2 (11%) and Man6GlcNAc2 (15%).
authors.affiliation: Department of Bioresources Chemistry, Faculty of Agriculture, Okayama University, Japan. yosh8mar@cc.okayama-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Kimura
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000276:immunology; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D000939:Epitopes / Q000737:chemistry; D020441:Ginkgo biloba / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D011058:Pollen / Q000737:chemistry* / Q000276:immunology
chemical_list: D000485:Allergens; D000939:Epitopes; D006023:Glycoproteins; D009844:Oligosaccharides