Advances of Separation and Enrichment Approach in Phosphoproteome Research

Protein phosphorylation is one of the most important reversible modifications in nature; it is involved in many cellular processes such as proliferation, differentiation, cellular signaling, transcriptional and translational regulation, interaction with other proteins, subcellular localization and the degradation of protein. So phosphorylation is one of the most common and best characterized post-translational modifications (PTM) of cellular proteins. The detection of phosphopeptides remains challenging because of the low abundance of phosphoproteins. The enrichment of phosphoproteins and phosphopeptides is one of the important ways to improve the MS response of phosphopeptide signals. This review summarizes the methods currently available for the enrichment of phosphoproteins and phosphopeptides, including immunopreciptation, affinity enrichment method, chemical modification method and affinity chromatography, on-plate specific enrichment method.