What is a Protein Post-Translational Modification Discovery

What is a Protein Post-Translational Modification Discovery?

Protein Post-Translational Modifications or PTM’s are identified by digesting proteins into peptides. The resulting peptides are analyzed using tandem mass spectrometry (LC-MS/MS) followed by database searches for modifications using X!tandem, SEQUEST, or other specialized PTM software. The observed post-translational modifications are usually verified by hand, and a likelihood score is produced. However, results can vary depending on the specific programs used.

More involved biochemical experiments may be needed if a new and previously unknonwn modification is discovered to validate the findings.