Related Experiment Video
Updated: Aug 17, 2026

LERLIC-MS/MS for In-depth Characterization and Quantification of Glutamine and Asparagine Deamidation in Shotgun Proteomics
Published on: April 9, 2017
Deamidation as a consequence of beta-elimination of phosphopeptides
Jonathan A Karty1, James P Reilly
1Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
Abstract:
Beta-elimination procedures often precede mass spectrometric analyses of phosphorylated peptides. Unfortunately, the commonly employed reaction conditions facilitate the deamidation of amide-containing residues. In addition to being 1 Da heavier than their amide counterparts, the newly created acidic residues greatly influence peptide tandem mass spectra. The effects of deamidation are investigated for five different amide-containing synthetic peptides exposed to beta-elimination conditions. MALDI-generated ions are analyzed with a tandem TOF mass analyzer. Methodologies for estimating the degree of deamidation from peptide mass spectra are presented, the influence that adjacent residues exert on the rate of deamidation is catalogued, and the impact that deamidation can have on peptide tandem mass spectra is demonstrated. The complications this side reaction can cause for automated data interpretation are also noted.
More Related Videos
Related Concept Videos
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Amines to Alkenes: Hofmann Elimination
Under thermal conditions, the hydroxide can abstract a proton from the β carbon; this generates an alkene with the simultaneous...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
Mass Spectrometry of Amines

