Selection of peptide biomarkers in human bone collagen for the evaluation of deamidation (N, Q) and oxidation (M) by targeted proteomics.

A shotgun proteomic approach was applied to the samples, and collagen type I chains have always been identified with good scores and confidence. Screening of all the mass spectrometric data was performed in search of the most frequently detected and/or deamidated peptides and the results were analyzed on a statistical basis to select the best peptides to be later used in the quantification of deamidation.