Native ion mobility (IM) mass spectrometry (MS) is used to probe the size, shape, and assembly of biomolecular complexes. IM-IM-MS can increase the amount of information available in structural studies by isolating subpopulations of structures for further analysis. Previously, IM-IM-MS has been implemented using the Structures for Lossless Ion Manipulations (SLIM) architecture to probe the structural stability of gas-phase protein ions. Here, a new multidimensional IM instrument constructed from SLIM devices is characterized using multiple operational modes. In this new design, modular devices are used to perform all ion manipulations, including initial accumulation, injection, separation, selection, and trapping. Using single-dimension IM, collision cross section (Ω) values are determined for a set of native-like ions. These Ω values are within 3% of those reported previously based on measurements using RF-confining drift cells. Tandem IM experiments are performed on a sample of ubiquitin ions that contains both compact and partially unfolded structures, demonstrating that this platform can isolate subpopulations of structures. Finally, additional modes of analysis, including multiplexed IM and inverse IM, are demonstrated using this platform. The ability of this platform to quickly switch between different modes of IM analysis makes it a highly flexible tool for studying protein structures and dynamics.

中文翻译：

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用于类原生离子多维离子淌度的灵活模块化平台

天然离子淌度 (IM) 质谱 (MS) 用于探测生物分子复合物的大小、形状和组装。IM-IM-MS 可以通过分离结构亚群以进行进一步分析，从而增加结构研究中可用的信息量。此前，IM-IM-MS 已使用无损离子操作结构 (SLIM) 架构实现，以探测气相蛋白质离子的结构稳定性。在这里，一种由 SLIM 设备构建的新型多维 IM 仪器具有多种操作模式的特点。在这种新设计中，模块化设备用于执行所有离子操作，包括初始积累、注入、分离、选择和捕获。使用单维 IM，可以确定一组类天然离子的碰撞截面 (Ω) 值。这些 Ω 值与之前使用 RF 限制漂移池进行测量时报告的值相差 3% 以内。串联 IM 实验是在包含紧凑和部分未折叠结构的泛素离子样本上进行的，表明该平台可以分离结构的亚群。最后，使用该平台演示了其他分析模式，包括多重 IM 和逆 IM。该平台能够在不同的 IM 分析模式之间快速切换，使其成为研究蛋白质结构和动力学的高度灵活的工具。