Multiplexed Charge Detection Mass Spectrometer for Extended Mass and Collisional Cross Section Measurements

项目摘要 大的生物分子组装体构成了大部分的分子机器， 细胞功能这些组装体通常是许多治疗分子的靶标。 其他大的生物分子组装体，包括病毒样颗粒、蛋白质样细胞组装体、 隔室和一些大的合成聚合物是这些药物的潜在递送剂。 治疗学参与细胞功能的大分子和分子组装体可以是 由于它们的高质量，使用常规质谱方法进行分析具有挑战性 （>MDa）和异质性。电喷雾离子化可以将完整的大 分子/复合物进入气相，但重叠和未解析的电荷状态， 由于高质量分析物固有的不均匀性， 使用传统的质谱仪。电荷检测质谱法称个体 离子，避免离子之间的这些干扰，并可用于分析分子， 质量远高于100 MDa。然而，这种方法可能很慢，因为只有一个离子被吸收。 分析一次。在这里，提出了新一代的电荷检测质谱 它提供了关于质量、碰撞截面和离解的信息 大分子复合物的单个离子的路径，不能被 使用常规仪器获得。一个关键的创新是多路复用的发展 可以同时称量许多单个离子的方法。这些方法 有可能将这些测量的速度提高150倍， 样品分析时间小于1分钟。这种离子多路复用是由一种新颖的 去耦方案，其中具有受控能量范围的离子被引入到 静电离子检测器阱，使得具有相同m/z的两个或更多个离子可以具有不同的m/z。 频率.每个离子的质量可以通过同时测量离子的浓度来获得。 单个离子频率、能量和电荷。该方案大大降低了潜在的 通过在宽的频率带宽上分布信号来重叠离子信号。率 离子能量变化也可以从这些测量中确定，提供信息 关于碰撞截面和分子形状的知识。同样，单个离子 可以跟踪碎片事件并用于获取额外的结构信息。

Project Summary Large biomolecular assemblies constitute much of the molecular machinery necessary for cellular function. These assemblies are often the target of a host of therapeutic molecules. Other large biomolecular assemblies, including virus-like particles, proteinaceous cellular compartments, and some large synthetic polymers, are potential delivery agents for these therapeutics. The large molecules and molecular assemblies involved in cellular function can be challenging to analyze using conventional mass spectrometry methods owing to their high mass (>MDa) and heterogeneity. Electrospray ionization can transfer intact large molecules/complexes into the gas phase, but overlapping and unresolved charge states that stem from the heterogeneity inherent to high mass analytes often prevent mass measurements using conventional mass spectrometers. Charge detection mass spectrometry weighs individual ions, avoiding these interferences between ions and can be used to analyze molecules with masses well above 100 MDa. However, this method can be slow because only one ion is analyzed at a time. Here, a new generation of charge detection mass spectrometry is proposed which provides information about the mass, the collisional cross section and the dissociation pathways of individual ions of large macromolecular complexes, information that cannot be obtained using conventional instruments. A key innovation is the development of multiplexing methods that make it possible to simultaneously weigh many individual ions. These methods have the potential to increase the speed of these measurements by up to 150x and reduce sample analysis times to less than one minute. This ion multiplexing is aided by a novel decoupling scheme whereby ions with a controlled range of energies are introduced into the electrostatic ion detector trap so that two or more ions with the same m/z can have different frequencies. The mass of each ion can be obtained from simultaneous measurements of the individual ion frequency, energy, and charge. This scheme significantly reduces the potential for overlapping ion signal by distributing the signal over a broad frequency bandwidth. The rate of ion energy change can also be determined from these measurements, providing information about collisional cross sections and giving insight into molecular shape. Similarly, individual ion fragmentation events can be tracked and used to obtain additional structural information.