An On-Line Platform for the Analysis of Permethylated Oligosaccharides Using Capillary Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry
作者:Kyoung-Soon Jang、Hae-Min Park、Yun-Gon Kim、Byung-Gee Kim、June-Hyung Kim
DOI:10.1166/jnn.2015.9534
日期:2015.5.1
Permethylation is one of the most practical modifications for mass spectrometric analysis of carbohydrates. In this study, we showed a facile platform for the on-line permethylation and analysis of acidic N-glycans using capillary liquid chromatography-electrospray ionization-tandem mass spectrometry to elucidate the N-glycan structures derived from glycoprotein samples. Two capillaries, individually packed with NaOH and C18 powder, were coupled to electrospray ion trap mass spectrometer. Prior to mass spectrometry, oligosaccharides were permethylated in NaOH-packed capillary by methyl iodide, and the permethylated glycans were consequently extracted from residual reagents, such as NaOH and methyl iodide, in C18-capillary, instead of using conventional chloroform extraction. After permethylation and purification, the permethylated glycans were released from C18 capillary by acetonitrile, and sprayed into mass spectrometer. Using this on-line strategy, a picomolar range of sialylated N-glycans from bovine fetuin were analyzed by tandem mass spectrometry.
过甲基化是碳水化合物质谱分析中最实用的修饰方法之一。在本研究中,我们展示了一种利用毛细管液相色谱-电喷雾离子化-串联质谱在线过甲基化和分析酸性N-聚糖的简便平台,以阐明来自糖蛋白样品的N-聚糖结构。两个分别装有 NaOH 和 C18 粉末的毛细管与电喷雾离子阱质谱仪相连。在进行质谱分析之前,寡糖在NaOH填充的毛细管中被碘甲烷过甲基化,然后在C18毛细管中从NaOH和碘甲烷等残留试剂中提取过甲基化的聚糖,而不是使用传统的氯仿萃取。经过过甲基化和纯化后,用乙腈将过甲基化的聚糖从 C18 毛细管中分离出来,然后喷入质谱仪。利用这种在线策略,采用串联质谱法分析了牛胎素中皮摩尔范围的糖基化 N-聚糖。