High-density monitoring of tyrosine phosphorylation signaling targets in human tumors using internal standard triggered targeted quantitation

SureQuant pTyr, a targeted, tyrosine phosphorylation (pTyr) mass spectrometry method, was applied to profile the pTyr signatures of human colorectal tumor samples. Using internal standard guided aquisition with the SureQuant acquisition mode on the Oribtrap Exploris 480 mass spectrometer (Thermo Scientific), the real-time detection of trigger peptides during analysis initiates the sensitive and selective quantitation of endogenous pTyr targets. This framework allows for reliable quantification of several hundred commonly dysregulated pTyr targets with high quantitative accuracy and improves the robustness and usability of targeted aquisition.