Microanalysis of Peptides Using an Ion Trap Storage/Time-of-Flight Mass Spectrometer

在这项工作中，我们将开发基于新仪器的方法，可用于生物重要性分子的结构分析，即肽和翻译后修饰肽。特别是，这将涉及离子阱/反射飞行时间质谱仪的进一步发展，以及这两种技术结合所产生的各种能力的发展。该装置将用于获取大肽和修饰肽的结构和序列信息，使用电喷雾或基质辅助激光解吸（MALDI）在外部产生离子以注入陷阱。离子阱将作为飞行时间质谱仪的前端存储设备，具有长期存储能力，从而为超痕量分析提供了可能。此外，这将提供研究这些大离子在陷阱中的光解离和碰撞诱导解离的能力，并检测长寿命的亚稳态碎片。这在大分子的情况下尤其重要，因为大分子只能在很长的时间尺度（10ms）上解离，这超出了许多质谱仪的能力。此外，各种因素，将允许足够的碎片解释这些大肽的结构将被调查。最后，使用碎片模式和亚稳离子分析提供了一个反射器的飞行时间，这种方法的结构分析能力将被评估。

In this work we will develop methodology based on new instrumentation which can be used for structural analysis of molecules of biological importance, i.e. peptides and post- translationally modified peptides. In particular, this will involve further development of an ion trap/reflectron time-of- flight mass spectrometer and the development of the various capabilities that result from a combination of these two technologies. This device will be used to obtain structure and sequence information on large peptides and modified peptides using electrospray or matrix-assisted laser desorption (MALDI) to produce ions externally for injection into the trap. The ion trap will act as a front end storage device for a time-of-flight mass spectrometer with capabilities for long-term storage thus providing the possibility for ultra trace analysis. In addition, this will provide the ability to investigate photodissociation and collision induced dissociation of these large ions in the trap with detection of long-lived metastable fragmentation. This will be especially important in the case of large molecules which may only dissociate on a long time scale (10 ms) that is beyond the capabilities of many mass spectrometer. In addition, various factors that will allow sufficient fragmentation for interpretation of the structure of these large peptides will be investigated. Ultimately, using fragmentation patterns and metastable ion analysis provided using a reflectron time-of- flight, the capabilities of this methodology for structural analysis will be evaluated.