Lössl Philip, Snijder Joost, Heck Albert J R
Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
J Am Soc Mass Spectrom. 2014 Jun;25(6):906-17. doi: 10.1007/s13361-014-0874-3. Epub 2014 Apr 4.
Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)-protein interactions, to nanomachineries such as the proteasome and ribosome, to even virus assembly. In native MS, ions attain high m/z values, requiring special mass analyzers for their detection. Depending on the particular mass analyzer used, instrumental mass resolution does often decrease at higher m/z but can still be above a couple of thousand at m/z 5000. However, the mass resolving power obtained on charge states of protein complexes in this m/z region is experimentally found to remain well below the inherent instrument resolution of the mass analyzers employed. Here, we inquire into reasons for this discrepancy and ask how native MS would benefit from higher instrumental mass resolution. To answer this question, we discuss advantages and shortcomings of mass analyzers used to study intact biomolecules and biomolecular complexes in their native state, and we review which other factors determine mass resolving power in native MS analyses. Recent examples from the literature are given to illustrate the current status and limitations.
在过去二十年中，原生质谱（MS）已成为研究完整蛋白质和非共价蛋白质复合物的重要工具。所研究的实验系统涵盖从小分子（药物）-蛋白质相互作用，到诸如蛋白酶体和核糖体等纳米机器，甚至包括病毒组装。在原生质谱中，离子具有较高的质荷比（m/z）值，需要特殊的质量分析器进行检测。根据所使用的特定质量分析器，仪器的质量分辨率在较高的质荷比下通常会降低，但在质荷比为5000时仍可高于几千。然而，实验发现，在该质荷比区域内蛋白质复合物电荷态所获得的质量分辨能力远低于所使用质量分析器的固有仪器分辨率。在此，我们探究这种差异的原因，并探讨原生质谱如何从更高的仪器质量分辨率中受益。为回答这个问题，我们讨论了用于研究天然状态下完整生物分子和生物分子复合物的质量分析器的优缺点，并回顾了在原生质谱分析中决定质量分辨能力的其他因素。文中给出了文献中的最新实例来说明当前的状况和局限性。
