Optimizing Native Ion Mobility Q-TOF in Helium and Nitrogen for Very Fragile Noncovalent Structures
Optimizing Native Ion Mobility Q-TOF in Helium and Nitrogen for Very Fragile Noncovalent Structures
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DOI：
10.1007/s13361-018-2029-4
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发表时间：
2018-11-01
影响因子：
3.2
通讯作者：
Rosu, Frederic
中科院分区：
文献类型：
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作者：
Gabelica, Valerie;Livet, Sandrine;Rosu, Frederic
在离子淌度池之前赋予离子的内部能量会影响离子结构，从而影响碰撞截面。具有很少内部自由度和/或高电荷密度的非共价配合物对碰撞激活特别敏感。在这里，我们研究了 Agilent 6560 IM-Q-TOF 的几乎所有调谐参数对泛素 (7+) 到达时间分布的影响，并发现了天然状态占主导地位的条件。我们讨论了源中溶剂蒸发条件、整个预 IM 直流电压梯度、漏斗 RF 幅度的影响。我们还报告了不同溶剂中的泛素 (7+) 构象，包括天然增压条件。碰撞诱导展开 (CIU) 可以在源毛细管后面或捕获漏斗中方便地引发。使用 DNA G 四链体 [(dG(4)T(4)G(4))(2)(NH4+)(3)-8H](5-) 进一步优化了流动池背后的仪器条件的柔软性，其中离子活化导致氨损失。为了降低离子内能并获得完整的 3-NH4+ 复合物，我们降低了 IM 后电压梯度，但这会由于漂移管后面的扩散增加而导致 IM 分辨率降低。本文介绍了非常脆弱结构的原生 MS 的离子激活、离子传输和离子淌度性能之间的各种权衡。
The amount of internal energy imparted to the ions prior to the ion mobility cell influences the ion structure and thus the collision cross section. Non-covalent complexes with few internal degrees of freedom and/or high charge densities are particularly sensitive to collisional activation. Here, we investigated the effects of virtually all tuning parameters of the Agilent 6560 IM-Q-TOF on the arrival time distributions of ubiquitin(7+) and found conditions in which the native state prevails. We discuss the effects of solvent evaporation conditions in the source, of the entire pre-IM DC voltage gradient, of the funnel RF amplitudes. We also report on ubiquitin(7+) conformations in different solvents, including native supercharging conditions. Collision-induced unfolding (CIU) can be conveniently provoked either behind the source capillary or in the trapping funnel. The softness of the instrumental conditions behind the mobility cell was further optimized with the DNA G-quadruplex [(dG(4)T(4)G(4))(2)(NH4+)(3)-8H](5-), for which ion activation results in ammonia loss. To reduce the ion internal energy and obtain the intact 3-NH4+ complex, we reduce the post-IM voltage gradient, but this results in a lower IM resolving power due to increased diffusion behind the drift tube. The article describes the various trade-offs between ion activation, ion transmission, and ion mobility performance for native MS of very fragile structures.