Sensitive targeted quantification of ERK phosphorylation dynamics and stoichiometry in human cells without affinity enrichment.

ABSTRACT: Targeted mass spectrometry is a promising technology for site-specific quantification of posttranslational modifications. However, a major constraint is the limited sensitivity for quantifying low-abundance PTMs, requiring the use of affinity reagents for enrichment. Herein, we demonstrate the direct site-specific quantification of ERK phosphorylation isoforms (pT, pY, pTpY) and their relative stoichiometry using a sensitive targeted MS approach termed high-pressure, high-resolution separations with intelligent selection, and multiplexing (PRISM). PRISM provides effective enrichment of target peptides into a given fraction from complex mixture, followed by selected reaction monitoring quantification. Direct quantification of ERK phosphorylation in human mammary epithelial cells (HMEC) was

SUBMITTER: Shi T 

PROVIDER: S-EPMC4365449 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature