Duplex Stable Isotope Labeling (DuSIL) for Simultaneous Quantitation and Distinction of Sialylated and Neutral N-Glycans by MALDI-MS.
Duplex Stable Isotope Labeling (DuSIL) for Simultaneous Quantitation and Distinction of Sialylated and Neutral N-Glycans by MALDI-MS.
复制标题
双稳定同位素标记 (DuSIL) 用于通过 MALDI-MS 同时定量和区分唾液酸化和中性 N-聚糖。
DOI：
10.1021/acs.analchem.8b02353
复制
发表时间：
2018
影响因子：
7.4
通讯作者：
Lu Haojie
中科院分区：
文献类型：
--
作者：
Wei Lei;Cai Yan;Yang Lijun;Zhang Ying;Lu Haojie
定量N-糖组学为检测癌症和其他疾病中的糖基化变化提供了有效的工具。然而，与中性聚糖相比，唾液酸的不稳定性及其较低的电离效率使其通过质谱法的分析变得复杂，并且阻止了通过MS同时定量和区分唾液酸化和中性N-聚糖。为了解决这个问题，我们开发了一种新的方法双重稳定同位素标记（DuSIL），通过MALDI-MS同时相对定量中性和唾液酸化聚糖。双链体标记策略包括唾液酸上的同位素甲基酰胺化标记和N-聚糖还原末端上的氨基酸还原胺化。使用该方法，标记的N-聚糖显示具有（6 + 3* N）Da质量差的双峰，用于相对定量和区分唾液酸的数量（N）。DuSIL标记方法具有标记效率高、重复性好（CV < 20%）、线性好（R2 > 0.99）等特点。该策略成功地应用于测量结直肠癌患者血清中IgG的N-聚糖变化，证明了其在临床样品中N-聚糖相对定量的潜力。
Quantitative N-glycomics provides an effective tool for detecting glycosylation changes in cancer and other diseases. However, the lability of sialic acid and its lower ionization efficiency compared with that of neutral glycans make their analysis by mass spectrometry complicated and prevents the simultaneous quantitation and distinction of sialylated and neutral N-glycans by MS. To address this problem, we developed a novel approach duplex stable isotope labeling (DuSIL), to relatively quantify neutral and sialylated glycans concurrently by MALDI-MS. The duplex labeling strategy includes isotopic methylamidation labeling on the sialic acids and amino acid reductive amination on the reducing ends of N-glycans. Using this method, the labeled N-glycans showed doublet peaks with (6 + 3* N) Da mass difference for relative quantitation and discrimination of the number of sialic acids ( N). The DuSIL strategy is of high labeling efficiency, high reproducibility (CV < 20%), and good linearity ( R2 > 0.99) within 2 orders of magnitude of dynamic range. The strategy is successfully applied to measure N-glycan changes of IgG from human serum with colorectal cancer, demonstrating its potential in relative quantitation of the N-glycome in clinical samples.