Assessing Enzyme Activities Using Stable Isotope Labeling and Mass Spectrometry

Assessing enzyme activities using stable isotope labeling and mass spectrometry.

Activity-based protein profiling has emerged as a valuable technology for labeling, enriching, and assessing protein activities from complex mixtures. This is primarily accomplished via a two-step identification and quantification process. Here we show a highly quantitative and streamlined method, termed catch-and-release activity profiling of enzymes (CAPE), which reduces this procedure to a s...

Comparative quantification and identification of phosphoproteins using stable isotope labeling and liquid chromatography/mass spectrometry.

A new liquid chromatography/mass spectrometry (LC/MS) method is described for relative quantification of phosphoproteins to simultaneously compare the phosphorylation status of proteins under two different conditions. Quantification was achieved by beta-elimination of phosphate from phospho-Ser/Thr followed by Micheal addition of ethanethiol and/or ethane-d(5)-thiol selectively at the vinyl moi...

Strategies and Challenges in Measuring Protein Abundance Using Stable Isotope Labeling and Tandem Mass Spectrometry

Quantitative Analysis of rRNA Modifications Using Stable Isotope Labeling and Mass Spectrometry

Post-transcriptional RNA modifications that are introduced during the multistep ribosome biogenesis process are essential for protein synthesis. The current lack of a comprehensive method for a fast quantitative analysis of rRNA modifications significantly limits our understanding of how individual modification steps are coordinated during biogenesis inside the cell. Here, an LC-MS approach has...

Assessing Enzyme Activities Using Mass Spectrometry and Novel Catch-and-Release Inhibitors