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Charge state dependent top‐down characterisation using electron transfer dissociation
Author(s) -
Rožman Marko,
Gaskell Simon J.
Publication year - 2011
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.5330
Subject(s) - electron transfer dissociation , chemistry , dissociation (chemistry) , ion , charge (physics) , analytical chemistry (journal) , electron , atomic physics , mass spectrometry , tandem mass spectrometry , chromatography , physics , organic chemistry , quantum mechanics
The dissociation of protein ions (5–30 kDa) as a function of charge state has been explored in order to suggest the optimal charge state range for top‐down sequencing. Proteins were generated under denaturing conditions and their charge states were modified via ion/ion proton transfer reactions prior to dissociation. Electron transfer dissociation (ETD) data suggested optimal sequence coverage for charge states in the m/z range from 700 to 950 while limited sequence coverage was noted when the precursor m/z was above 1000. Sequence coverage from ETD data was found to be dependent on protein size, with smaller proteins having better sequence coverage. An observed depletion in sequence‐related information was mainly attributed to limited instrument (ion trap) performance ( m/z range and resolution). For a combined ETD/collision‐induced dissociation (CID) approach it is difficult to propose an optimal m/z range since good sequence coverage for CID is at intermediate charge states and the optimal m/z range increases with protein size. When only one charge state can be analysed in a combined ETD/CID approach, a range around 950 m/z is suggested as a starting point. Alternatively, two charge states should be explored, each optimal for either ETD or CID. Overall, these suggestions should be useful to achieve enhanced characterisation of smaller proteins/large protein fragments (generated from denaturing solutions) in minimal analysis times. Copyright © 2011 John Wiley & Sons, Ltd.