Many proteins can be post-translationally modified. These modifications can be dynamic with time, cell cycle state or in response to stresses. PTMs may regulate enzymatic activity, binding properties or target proteins for degradation or to specific cellular compartments. It is for this reason that many biologists are interested in characterizing the post-translational modifications present in their protein or proteome samples.
The PMSF offers several services that can assist in PTM analysis. These include PTM specific staining of 1D/2D gels, ProQ Diamond (phosphoprotein) and PorQ Emerald (glycoprotein) and LC-MS/MS based phosphoprotein enrichment and analysis. LC-MS/MS based phosphoprotein analysis entails enriching for phosphoproteins using a phosphoprotein specific resin prior to LC-MS/MS analysis and data analysis for reporting the number and localization of phosphorylation sites. Depending on the sample complexity, some pre-fractionation may be required prior to LC-MS/MS. Both gel- and LC--MS/MS-based analyses can be combined with quantitation to compare sample types, time-points or treatments.