Premium
Study of the dissociation of a charge‐reduced phosphopeptide formed by electron transfer from an alkali metal target
Author(s) -
Hayakawa Shigeo,
Hashimoto Mami,
Nagao Hirofumi,
Awazu Kunio,
Toyoda Michisato,
Ichihara Toshio,
Shigeri Yasushi
Publication year - 2008
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.3399
Subject(s) - chemistry , ion , dissociation (chemistry) , fragmentation (computing) , mass spectrum , electron transfer dissociation , electron capture dissociation , electron ionization , protonation , electrospray ionization , collision induced dissociation , mass spectrometry , ionization , analytical chemistry (journal) , tandem mass spectrometry , chromatography , organic chemistry , computer science , operating system
Doubly protonated phosphopeptide (YGGMHRQET(p)VDC) ions obtained by electrospray ionization were collided with Xe and Cs targets to give singly and doubly charged positive ions via collision‐induced dissociation (CID). The resulting ions were analyzed and detected by using an electrostatic analyzer (ESA). Whereas doubly charged fragment ions resulting from collisionally activated dissociation (CAD) were dominant in the CID spectrum with the Xe target, singly charged fragment ions resulting from electron transfer dissociation (ETD) were dominant in the CID spectrum with the Cs target. The most intense peak resulting from ETD was estimated to be associated with the charge‐reduced ion with H 2 lost from the precursor. Five c‐type fragment ions with amino acid residues detached consecutively from the C‐terminal were clearly observed without a loss of the phosphate group. These ions must be formed by NC α bond cleavage, in a manner similar to the cases of electron capture dissociation (ECD) and ETD from negative ions. Although the accuracy in m/z of the CID spectra was about ±1 Th because of the mass analysis using the ESA, it is supposed from the m/z values of the c‐type ions that these ions were accompanied by the loss of a hydrogen atom. Four z‐type (or yNH 3 , or yH 2 O) ions analogously detached consecutively from the N‐terminal were also observed. The fragmentation processes took place within the time scale of 4.5 µs in the high‐energy collision. The present results demonstrated that high‐energy ETD with the alkali metal target allowed determination of the position of phosphorylation and the amino acid sequence of post‐translational peptides. Copyright © 2008 John Wiley & Sons, Ltd.