SH2 domains as affinity reagents for phosphotyrosine protein enrichment and proteomic analysis

Dynamic tyrosine phosphorylation is a key molecular modulation for many signal transduction events. Because of their low abundance and dynamic nature in cells, the detection and enrichment of phosphotyrosine proteins has long relied on specific antibodies, such as 4G10 and P-Tyr-100. Another well-established approach for phosphotyrosine proteins recognition and enrichment is by their specific binding domains, such as Src homology 2 (SH2) domains. In this chapter, we describe a typical analytical approach for purifying specific SH2 domains, enriching specific phosphotyrosine proteins from activated cells, mass spectrometry analysis, and related data analysis.