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: 8290324
• 负责人: Evan R Williams
• 金额: $ 22.92万
• 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/8290324
• 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）：质谱法正迅速成为一种用于大分子复合物结构解析的强有力方法，并可为常规生物物理方法提供补充信息。完整的复合物可以用电喷雾电离从溶液中提出，这给这些分子组装体增加了许多电荷。实验表明，在许多情况下，这些气相离子保留了它们溶液相结构的许多元素。直接的质量测量提供了一个快速测量的配合物的化学计量，即使是非均匀的混合物。复合物的片段化可以产生关于复合物内亚基的连接性的信息。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，使得获得互补的形状信息成为可能。将质谱法应用于更大的复合物的挑战是样品的异质性，这可能导致未解析的电荷状态分布。另一个挑战是，许多质谱仪的灵敏度随着质荷比（m/z）的增加而降低，这使得更难以以高灵敏度检测分子量为几兆道尔顿或更高的复合物。电喷雾离子化的一个方面是带电程度通常随着分子大小而增加。这使得电荷检测质谱法成为分析大分子复合物的有吸引力的手段，因为它具有可以容易地检测具有多个电荷的单个离子的优点。因为电荷会随着尺寸的增加而增加，所以这种技术的灵敏度实际上随着分子量的增加而提高。样品的异质性不会干扰质量或迁移率测量，因为每个离子都是单独分析的。我们计划开发一种质量和迁移率的单粒子分析仪（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。这一双静电离子阱仪器将具备串联质谱分析能力，从而能够测量已知质量的单个离子的碎裂谱（初步研究将侧重于红外多光子解离，但也可采用其他方法）。最后，离子迁移能力将被集成到该设备中，以便能够测量离子的质量，并随后获得其绝对碰撞截面，这提供了有关复合物形状的信息。也可以获得由复合物解离产生的片段的横截面，提供关于亚基连接性对复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成正比，因此灵敏度应随着颗粒尺寸的增加而增加，使得该方法适用于比目前可用市售质谱仪分析的大得多的非均相复合物。