2D-O1-1010 PDF
静電型イオンストレージリングを用いた電子－イオン散乱の研究
Electron mediated fragmentation techniques such as Electron capture dissociation (ECD) and Electron transfer dissociation (ETD) are widely used for peptide/protein sequencing. ECD reduces c/z fragment pairs by N-Cα bond cleavage via nonergonic process in contrast to b/y fragment pairs in collisionally activated dissociations. The detailed mechanism of the process is not understood so far. One of interesting question is the recombination site of free electron to the multiply protonated ions. Tanabe has reported resonant neutral particle emission at 6.5 eV in collisions of electrons with peptide ions using electrostatic storage ring. The neutral production rate for singly protonated amino acid increase gradually with the energies and do not show any prominent resonance structure. These results suggest that the origin of the resonance structure is not from amino acid itself, but from the structure of peptide linkages.
In order to confirm the energy dependence with peptide bond, we performed experiments with Acetyl-Arginin and Acetyl-Lysin. Experiments were performed using an electrostatic storage ring of KEK in combination with a merged electron-beam.