3C-O2-1545 PDF
Comparative study of 20keV/TOF-TOF high-energy CID and eV/QIT low-energy CID of fragment ions generated from MALDI-ISD of phosphorylated peptide and protein
The CID spectra obtained with QIT low-energy and TOF/TOF high-energy collision experiments were compared for the fragment ions generated by MALDI-ISD of phosphorylated peptide and protein. The high-energy CID resulted in the peaks representing the number of phosphate and the product a-, b- and d-ions characterized by prompt radical cleavages due to electronic excitation, while the low-energy CID brought about specific cleavages originated from the proline effect and mobile proton mechanism which are characterized by charge-initiated cleavages with conformational change due to vibrational/rotational excitation.