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Journal of Systems Biology & Proteome Research
|
Volume 2
J u n e 2 5 - 2 7 , 2 0 1 8 | D u b l i n , I r e l a n d
MASS SPECTROMETRY
AND PROTEOMICS
International Conference on
TWO ARE BETTER THAN ONE: WHY TO CONSIDER ESI AND
MALDI
Christoph Roesli
Novartis Pharma AG, Switzerland
F
or mass spectrometry-based proteomic analyses, matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization
(ESI) are the commonly used ionization techniques. Investigations performed on very large datasets with more than 72000 peptides
showed the complementary character of the two methods not only regarding the identified peptides but also with respect to their amino
acid composition, hydrophobicity, charge-related parameters and post-translational modifications. Focusing on phosphopeptides enriched
by Fe-IMAC chromatography, considerable orthogonality between the two analytical workflows were identified. For instance, laser-based
ionization allowed for the identification of an unexpectedly high number and percentage of phosphotyrosine sites. Furthermore, MALDI-
TOF MS/MS clearly favored the identification of motif signatures for acidic residue directed kinases. In summary, the investigation of
large-scale datasets using both LC-ESI-MS and off-line LC coupled to MALDI-MS allows for the generation of a complete dataset of
peptides and post-translational modifications.
christoph.roesli@gmail.comJ Syst Biol Proteome Res 2018, Volume 2