Analysis Of Postranslational Modifications.
Mass spectrometry is also used for the study of post-translational modifications in proteins. For instance, protein phosphorylation, which is so common with in the cell, can be deteched by mass spectrometry. However, it requires more time and additional preparative steps. When Tryptic peptides are usually analysed in mass spectrometer, the phosphorylated peptides may need to be separated from non-phosphorylated peptides, the presence of which may obscure the signal from the phosphorylated peptides. Since, detection of the exact phosphorylated residue may still be difficult, it might be worthwhile to identify the relevant peptides that are phosphorylated by treatment with phosphatase and observe the mass difference of the peptides before and after treatment.