PNNL

Abstract

Comprehensive phosphoproteomic analysis of small populations of cells remains a daunting task due primarily to the insufficient MS signal intensity from low concentrations of enriched phosphopeptides. Isobaric labeling has a unique multiplexing feature where the “total” peptide signal from all channels (or samples) triggers MS/MS fragmentation for peptide identification while the reporter ions provide quantitative information. In light of this feature, we tested the concept of using a “boosting” sample (e.g., a biological sample mimicking the study samples but available in much larger quantity) in multiplexed analysis to enable sensitive and comprehensive quantitative phosphoproteomic measurements with