Post-translational modifications (PTMs) – such as phosphorylation, glycosylation or ubiquitination – can be identified and localised by mass spectrometry. The workflow is similar to standard protein identification: proteins are digested into peptides, separated by HPLC and analysed by MS. However, PTM analysis is more complex. We must detect the specific modified peptide, not just any fragment, and peptide ionisation efficiency varies by sequence – meaning not all peptides are always observed. High sample quality and quantity are essential, and enrichment or protocol adjustments are often needed.
Please contact our team before sending samples to discuss the best approach.