Send to

Choose Destination
See comment in PubMed Commons below
J Am Soc Mass Spectrom. 2010 Jun;21(6):1012-5. doi: 10.1016/j.jasms.2010.02.002. Epub 2010 Feb 8.

Electron transfer dissociation with supplemental activation to differentiate aspartic and isoaspartic residues in doubly charged peptide cations.

Author information

Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China.


Electron-transfer dissociation (ETD) with supplemental activation of the doubly charged deamidated tryptic digested peptide ions allows differentiation of isoaspartic acid and aspartic acid residues using the c + 57 or z*-57 peaks. The diagnostic peak clearly localizes and characterizes the isoaspartic acid residue. Supplemental activation in ETD of the doubly charged peptide ions involves resonant excitation of the charge reduced precursor radical cations and leads to further dissociation, including extra backbone cleavages and secondary fragmentation. Supplemental activation is essential to obtain a high quality ETD spectrum (especially for doubly charged peptide ions) with sequence information. Unfortunately, the low-resolution of the ion trap mass spectrometer makes detection of the diagnostic peak, [M-60], for the aspartic acid residue difficult due to interference with side-chain loss from arginine and glutamic acid residues.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Springer Icon for PubMed Central
    Loading ...
    Support Center