银杏种子糖蛋白的SDS-PAGE分离及N-糖链的质谱分析

利用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)分离了银杏种子中的糖蛋白组分, 进一步用氨水催化释放N-糖链, 并采用电喷雾离子质谱(ESI-MS)及在线液相色谱-质谱联用(LC-UV-MS/MS²)等技术对胶条上释放的N-糖链进行了定性定量分析. 结果表明, 从银杏种子中分离得到11种糖蛋白, 共检测到11条N-糖链, 包括高甘露糖型(4.88%)和复杂型(95.12%) 2种类型, 其中分子量为21000, 36000和50000的糖蛋白所释放的核心α-1,3-岩藻糖和β-1,2-木糖修饰的N-糖链所占比率较高, 分别为68.23%, 64.37%和75.09%. 本研究对进一步研究银杏糖蛋白功能具有重要意义.

Mass Spectrometric Analysis of N-Glycans of Glycoprotein Separated by SDS-PAGE Gel from Ginkgo Seed†

The glycoproteins in Ginkgo seeds were separated and isolated by sodium dodecyl sulfate polyacry-lamide gel electrophoresis(SDS-PAGE). The N-glycans released from glycoproteins were qualitatively and quantitatively analyzed by electrospray ionization mass spectrometry(ESI-MS) and on-line liquid chromatography-mass spectrometry(LC-UV-MS/MS²). As a result, eleven glycoproteins containing oligomannose type glycans(4.88%) and complex type glycans(95.12%) were obtained. And most of the N-glycans were modified by the core α-1, 3- and β-1, 2-xylose in the 21000, 36000 and 50000 glycoproteins, which accounted for 68.23%, 64.37% and 75.09%, respectively. This study can highlight the understanding of protein glycosylation in Ginkgo and provide foundation in the research of Ginkgo biloba seed allergens.