Phosphoproteome enrichment strategy using complementary chemistries of Fe-NTA and TiO2 followed by LC-MS/MS

The global phosphoproteome analysis by liquid chromatography-mass spectrometry (LC-MS) has emerged as an important tool to study cell signalling. However, the coverage of phosphoproteome by LC-MS is limited despite various approaches for phosphoprotein enrichment. Studies in literature have exploited the complementary chemistries of affinity materials like metal (immobilized metal ion affinity chromatography- IMAC) and metal oxides (metal oxide affinity chromatography- MOAC) independently and in a sequential elution approach to improve coverage of phosphoproteins. We demonstrate that further improvement in the enrichment of phosphoproteins can be achieved by using these metals and metal oxides independently and pooling the data.