Development of Single Particle Analyzer of Mass and Mobility (SPAMM)

单粒子质量和迁移率分析仪（SPAMM）的开发

• 批准号: 8499373
• 负责人: Evan R Williams
• 金额: $ 22.12万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8499373
• 关键词: Buffers; Cell Mobility; Cell physiology; Charge; Chemistry; Complex; Coupled; Data; Detection; Development; Devices; Dissociation; Electrospray Ionization; Electrostatics; Elements; Fourier Transform; Gases; Helium; Heterogeneity; Individual; Ions; Lifting; Macromolecular Complexes; Mass Spectrum Analysis; Measurement; Measures; Methods; Modification; Molecular; Molecular Weight; Nitrogen; Particle Size; Phase; Photons; Play; Relative (related person); Reporting; Resolution; Role; Sampling; Services; Shapes; Solutions; Structure; System; Techniques; Therapeutic Agents; Time; Travel; Vacuum; austin; base; dalton; density; design; electric field; experience; improved; instrument; instrumentation; ion mobility; ionization; mass analyzer; mass spectrometer; molecular assembly/self assembly; molecular size; nanoscale; particle; pressure; programs; research study; stoichiometry; tandem mass spectrometry; theories

DESCRIPTION (provided by applicant): Mass spectrometry is rapidly becoming a powerful method for the structural elucidation of macromolecular complexes, and can provide complimentary information to conventional biophysical methods. Intact complexes can be lifted out of solution with electrospray ionization, which adds many charges to these molecular assemblies. Experiments have shown that in numerous cases, these gas-phase ions retain many elements of their solution-phase structure. A direct mass measurement provides a rapid measure of the stoichiometry of complexes, even for heterogeneous mixtures. Fragmentation of complexes can yield information about the connectivity of subunits within the complex. Additionally, ion mobility-based approaches are beginning to provide cross-sectional measurements of complexes, making it possible to obtain complementary shape information. A challenge in applying mass spectrometry to even larger complexes is sample heterogeneity, which can result in unresolved charge-state distributions. An additional challenge is that the sensitivity of many mass spectrometers decreases with increasing mass-to-charge ratio (m/z), which makes it more difficult to detect complexes with molecular weights of several mega Daltons and higher with high sensitivity. One aspect of electrospray ionization is that the degree of charging generally increases with molecular size. This makes charge detection mass spectrometry an attractive means of analyzing large macromolecular complexes, because it has the advantage that individual ions possessing multiple charges can be readily detected. Because charge will increase with size, the sensitivity of this technique actually improves with increasing molecular weight. The heterogeneity of the sample does not interfere with mass or mobility measurements, because each ion is analyzed individually. We plan to develop a Single Particle Analyzer of Mass and Mobility (SPAMM), which will incorporate m/z and charge detection measurements so that the masses of individual ions can be rapidly measured. Tandem mass spectrometry capabilities will be incorporated into this dual electrostatic ion trap instrument which will make it possible to measure a fragmentation spectrum of an individual ion of known mass (initial studies will focus on infrared multiple photon dissociation, although other methods could also be incorporated). Finally, ion mobility capabilities will be integrated into this device to make it possible to measure the mass of an ion, and subsequently obtain its absolute collision cross section, which provides information about the shape of the complex. Cross sections can also be obtained for fragments generated by the dissociation of a complex, providing information about the contribution of subunit connectivity to the overall structure of the complex. Because the induced current in this device is directly proportional to the number of charges on the macromolecular complex, sensitivity should increase with increasing particle size making this method applicable too much larger heterogeneous complexes than can be currently analyzed with commercially available mass spectrometers.

描述（由申请人提供）：质谱法正在迅速成为一种强大的大分子复合物结构解析方法，并且可以提供传统生物物理方法的补充信息。完整的配合物可以通过电喷雾电离从溶液中分离出来，这给这些分子组件增加了许多电荷。实验表明，在许多情况下，这些气相离子保留了溶液相结构的许多元素。直接质量测量提供了一个快速测量的化学计量的配合物，即使是异质混合物。配合物的碎片化可以产生有关配合物内亚基连通性的信息。此外，基于离子迁移率的方法开始提供复合物的横截面测量，使获得互补形状信息成为可能。将质谱法应用于更大的配合物的挑战是样品的异质性，这可能导致无法解决的电荷态分布。另一个挑战是，许多质谱仪的灵敏度随着质量电荷比（m/z）的增加而降低，这使得检测分子量为几兆道尔顿的配合物变得更加困难，而高灵敏度的配合物则更高。电喷雾电离的一个方面是，电荷的程度通常随着分子的大小而增加。这使得电荷检测质谱法成为分析大型大分子复合物的一种有吸引力的方法，因为它的优点是可以很容易地检测到具有多个电荷的单个离子。因为电荷会随着尺寸的增加而增加，这种技术的灵敏度实际上会随着分子量的增加而提高。样品的非均质性不会干扰质量或迁移率的测量，因为每个离子都是单独分析的。我们计划开发一种单粒子质量和迁移率分析仪（SPAMM），它将结合m/z和电荷检测测量，以便可以快速测量单个离子的质量。串联质谱分析功能将被整合到这个双静电离子阱仪器中，这将使测量已知质量的单个离子的碎片谱成为可能（最初的研究将集中在红外多光子解离，尽管其他方法也可以被纳入）。最后，离子迁移能力将集成到该装置中，从而可以测量离子的质量，并随后获得其绝对碰撞截面，从而提供有关复合物形状的信息。还可以获得由配合物解离产生的片段的横截面，提供有关亚基连通性对配合物整体结构的贡献的信息。由于该装置中的感应电流与大分子复合物上的电荷数量成正比，因此灵敏度应随着粒径的增加而增加，这使得该方法适用于比目前市售质谱仪分析的更大的非均相复合物。