Manchester Institute of Biotechnology, Michael Barber Centre for Mass Spectrometry, School of Chemistry, University of Manchester, Manchester, M1 7DN, United Kingdom.
J Proteome Res. 2012 Nov 2;11(11):5564-72. doi: 10.1021/pr3005327. Epub 2012 Oct 9.
Ion mobility-mass spectrometry (IM-MS) is a useful technique for determining information about analyte ion conformation in addition to mass/charge ratio. The physical principles that govern the mobility of an ion through a gas in the presence of a uniform electric field are well understood, enabling rotationally averaged collision cross sections (Ω) to be directly calculated from measured drift times under well-defined experimental conditions. However, such "first principle" calculations are not straightforward for Traveling Wave (T-Wave) mobility separations due to the range of factors that influence ion motion through the mobility cell. If collision cross section information is required from T-Wave mobility separations, then calibration of the instruments using known standards is essential for each set of experimental conditions. To facilitate such calibration, we have designed and generated an artificial protein based on the QconCAT technology, QCAL-IM, which upon proteolysis can be used as a universal ion mobility calibration standard. This single unique standard enables empirical calculation of peptide ion collision cross sections from the drift time on a T-Wave mobility instrument.
离子淌度-质谱联用（IM-MS）是一种有用的技术，除了质量/电荷比之外，还可以确定分析物离子构象的信息。在存在均匀电场的情况下，控制离子在气体中迁移的物理原理得到了很好的理解，从而可以根据测量的漂移时间在明确定义的实验条件下直接计算旋转平均碰撞截面（Ω）。然而，由于影响离子通过迁移率池运动的因素范围很广，对于行波（T-Wave）迁移率分离来说，这样的“第一性原理”计算并不简单。如果需要从 T-Wave 迁移率分离中获得碰撞截面信息，那么使用已知标准对仪器进行校准对于每组实验条件都是必不可少的。为了便于这种校准，我们设计并生成了一种基于 QconCAT 技术的人工蛋白质，即 QCAL-IM，它在蛋白酶解后可以用作通用的离子迁移率校准标准。这种单一独特的标准可以从 T-Wave 迁移率仪器上的漂移时间计算肽离子碰撞截面。
