Authors: Dominic Winter Wolf D Lehmann
Publish Date: 2009/02/12
Volume: 393, Issue: 6-7, Pages: 1587-1591
Abstract
The N terminus of peptides generated by AspN is restricted to about 40 dipeptide motifs starting with D or E These motifs are visible upon collisioninduced dissociation CID as b2 ions which are often the most abundant lowmass fragment ions It was observed that b2 ions are accompanied by a set of sequencespecific neutral losses of CO H2O NH3 and some other small units To test the utility of these profiles as additional parameters for reliable assignment of the b2 ion motif besides its m/z value the CID spectra of 221 different AspNgenerated peptides covering all Nterminal DX and EX motifs were recorded Qualitatively the b2 ion fragmentation profiles of individual motifs were found to exhibit little dependency on the rest of the peptide sequence Thus it is concluded that the set of b2 ion fragmentation profiles recorded in this study can be used as reference set Knowledge of these profiles provides an increased specificity for b2 ion annotation of AspNgenerated peptides compared to the use of only a solitary b2 ion m/z value Recognition of the b2 ion motif provides a twoaminoacid sequence including its direction it provides the location of this motif at the N terminus and it sets a starting point for further extension of the b ion seriesWe are indebted to R Pipkorn DKFZ Heidelberg for expert peptide synthesis This work was supported in part by the Cooperation Program in Cancer Research of the German Cancer Research Center DKFZ and Israeli’s Ministry of Science and Technology MOST The authors declare no conflict of interest
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