Faculty of Chemistry, Aalen University, 73430, Aalen, Germany.
Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
Anal Bioanal Chem. 2019 Sep;411(24):6255-6264. doi: 10.1007/s00216-018-1515-7. Epub 2018 Dec 10.
Capillary zone electrophoresis (CZE) based on electrophoretic mobility in the liquid phase and ion mobility spectrometry (IMS) based on mobilities in the gas phase are both powerful techniques for the separation of complex samples. Protein glycosylation is one of the most common post-translational modifications associated with a wide range of biological functions and human diseases. Due to their high structural variability, the analysis of glycans still represents a challenging task. In this work, the first on-line coupling of CZE with drift tube ion mobility-mass spectrometry (DTIM-MS) has been perfomed to further improve separation capabilities for the analysis of native and 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled N-glycans. In this way, a complexity of glycan signals was revealed which could not be resolved by these techniques individually, shown for both native and APTS-labeled glycans. Each individual glycan signal separated in CZE exhibited an unexpectedly high number of peaks observed in the IMS dimension. This observation could potentially be explained by the presence of isomeric forms, including different linkages, and/or gas-phase conformers. In addition, the type of sialic acid attached to glycans has a significant impact on the obtained drift time profile. Furthermore, the application of α2-3 neuraminidase enabled the partial assignment of peaks in the arrival time distribution considering their sialic acid linkages (α2-3/α2-6). This work is a showcase for the high potential of CZE-DTIM-MS, which is expected to find various applications in the future. Graphical abstract ᅟ.
基于液相电泳迁移率的毛细管区带电泳(CZE)和基于气相迁移率的离子淌度谱(IMS)都是分离复杂样品的强大技术。蛋白质糖基化是与广泛的生物学功能和人类疾病相关的最常见的翻译后修饰之一。由于其结构高度可变,聚糖的分析仍然是一项具有挑战性的任务。在这项工作中,首次将 CZE 与漂移管离子淌度-质谱(DTIM-MS)在线耦合,以进一步提高分析天然和 8-氨基芘-1,3,6-三磺酸(APTS)标记的 N-聚糖的分离能力。通过这种方式,揭示了这些技术单独无法分辨的聚糖信号的复杂性,无论是天然的还是 APTS 标记的聚糖都得到了证明。在 CZE 中分离的每个单独的聚糖信号在 IMS 维度上表现出数量出乎意料的多的峰。这种观察结果可能可以通过存在异构形式来解释,包括不同的键合和/或气相构象。此外,连接到聚糖上的唾液酸类型对获得的漂移时间分布有显著影响。此外,α2-3 神经氨酸酶的应用使得在考虑其唾液酸键合(α2-3/α2-6)时,对到达时间分布中的峰进行部分分配成为可能。这项工作展示了 CZE-DTIM-MS 的巨大潜力,预计在未来将有各种应用。