Enrichment techniques employed in phosphoproteomics

Reversible protein phosphorylation represents one of the most rapid and dynamic posttranslational modifications. Phosphorylation plays a key role in many cellular processes, e.g. cell division, signal transduction, cytoskeleton dynamics, translation regulation, protein targeting and metabolism. Unfortunately, the importance of phosphoproteins is often not mirrored in their abundance so enriching strategies are mostly inevitable. The enrichment can be performed either at the stage of phosphoproteins or at the stage of phosphopeptides. Alternatively, a combination of both strategies can be used. Most enriching strategies are based on chemical modifications, affinity of phosphates to positively-charged chromatography matrix or antibodies. Every method used has its advantages as well as disadvantages. Moreover, satisfactory coverage of phosphoproteome is very often reached by combination of several methods. In the past five years many protocols have been improved or alternatively new approaches have appeared. So in this bachelor thesis, the available enrichment strategies are reviewed. Key words: phosphoproteomics, phosphoprotein enrichment, phosphopeptide enrichment, IMAC, MOAC, titanium dioxide TiO2, aluminium hydroxide Al(OH)3, antibodie