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

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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.