Paglia Giuseppe, Williams Jonathan P, Menikarachchi Lochana, Thompson J Will, Tyldesley-Worster Richard, Halldórsson Skarphédinn, Rolfsson Ottar, Moseley Arthur, Grant David, Langridge James, Palsson Bernhard O, Astarita Giuseppe
Center for Systems Biology, University of Iceland , IS 101, Reykjavik, Iceland.
Anal Chem. 2014 Apr 15;86(8):3985-93. doi: 10.1021/ac500405x. Epub 2014 Mar 28.
Metabolomics is a rapidly evolving analytical approach in life and health sciences. The structural elucidation of the metabolites of interest remains a major analytical challenge in the metabolomics workflow. Here, we investigate the use of ion mobility as a tool to aid metabolite identification. Ion mobility allows for the measurement of the rotationally averaged collision cross-section (CCS), which gives information about the ionic shape of a molecule in the gas phase. We measured the CCSs of 125 common metabolites using traveling-wave ion mobility-mass spectrometry (TW-IM-MS). CCS measurements were highly reproducible on instruments located in three independent laboratories (RSD < 5% for 99%). We also determined the reproducibility of CCS measurements in various biological matrixes including urine, plasma, platelets, and red blood cells using ultra performance liquid chromatography (UPLC) coupled with TW-IM-MS. The mean RSD was < 2% for 97% of the CCS values, compared to 80% of retention times. Finally, as proof of concept, we used UPLC-TW-IM-MS to compare the cellular metabolome of epithelial and mesenchymal cells, an in vitro model used to study cancer development. Experimentally determined and computationally derived CCS values were used as orthogonal analytical parameters in combination with retention time and accurate mass information to confirm the identity of key metabolites potentially involved in cancer. Thus, our results indicate that adding CCS data to searchable databases and to routine metabolomics workflows will increase the identification confidence compared to traditional analytical approaches.
代谢组学是生命科学和健康科学中一种快速发展的分析方法。在代谢组学工作流程中，对感兴趣的代谢物进行结构解析仍然是一项重大的分析挑战。在此，我们研究了将离子淌度用作辅助代谢物鉴定的工具。离子淌度能够测量旋转平均碰撞截面（CCS），该截面可提供有关气相中分子离子形状的信息。我们使用行波离子淌度-质谱联用仪（TW-IM-MS）测量了125种常见代谢物的CCS。在位于三个独立实验室的仪器上，CCS测量具有高度可重复性（99%的测量值相对标准偏差<RSD<5%）。我们还使用超高效液相色谱（UPLC）与TW-IM-MS联用，测定了包括尿液、血浆、血小板和红细胞在内的各种生物基质中CCS测量的可重复性。与80%的保留时间相比，97%的CCS值的平均RSD<2%。最后，作为概念验证，我们使用UPLC-TW-IM-MS比较上皮细胞和间充质细胞的细胞代谢组，这是一种用于研究癌症发展的体外模型。实验测定和计算得出的CCS值与保留时间和精确质量信息一起用作正交分析参数，以确认可能参与癌症的关键代谢物的身份。因此，我们的结果表明，与传统分析方法相比，将CCS数据添加到可搜索数据库和常规代谢组学工作流程中将提高鉴定的可信度。
