Here, we present unbiased quantification of site-specific protein acetylation and/or succinylation occupancy (stoichiometry) of an entire proteome through a ratiometric analysis of endogenous modifications to modifications introduced after quantitative chemical acylation using stable isotope-labeled anhydrides. In combination with sensitive data-independent acquisition mass spectrometry, accurate site occupancy measurements are obtained.
The overall goal of this novel workflow is to determine the occupancy or stoichiometry of protein post-translational modifications at specific acetylation sites.This novel mass spectrometric workflow provides a higher level of precision of quantification.This method can help answer key questions about reversible protein regulation by post translational modification such as lysine acetylation or succinylation sites are most highly modified and may alter protein function.The main advantage of this technique is that site level stoichiometry of lysine acetylation and succinylation and succinylation are accurately determined and the method can determine stoichiometry from peptides with multiple lysine residues.This technique is highly relevant because it reveals acetylation and succinylation stoichiometry or proportion modified versus unmodified instead of measuring a dimensionless relative abundance change.I first had the idea for this method when I realized that using data independent acquisitions and MS2 based quantification for stoichiometry analysis would greatly improve measurement accuracy.Prepare three replicates of 100
