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Updated: Aug 22, 2025

Quantification of Site-specific Protein Lysine Acetylation and Succinylation Stoichiometry Using Data-independent Acquisition Mass Spectrometry
Published on: April 4, 2018
Quantitative profiling of PTM stoichiometry by resolvable mass tags
Ying Chen1,2,3,4, Baiyi Quan1,2,3,4, Yuanpei Li1,2,3,4
1College of Chemistry and Molecular Engineering, Peking University Beijing China chuwang@pku.edu.cn.
Abstract:
Post-translational modifications (PTMs) play important roles in modulating the biological functions of proteins. Stoichiometry, which quantifies the modification percentage, is a critical factor for any given PTM. In this work, we developed a chemoproteomic strategy called "STO-MS" to systematically quantify the PTM stoichiometry in complex biological samples. This strategy employs a resolvable mass tag to differentiate proteoforms with different numbers of modifications and utilizes liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) techniques to measure PTM stoichiometry at the proteomic level. As a proof-of-concept, we successfully determined the stoichiometry of 197 proteins modified by 4-hydroxynonenal (HNE), a well-characterized lipid-derived electrophile and biomarker for oxidative stress. Our work expands the toolbox for quantification of PTM stoichiometry and sheds light on understanding the biological significance of PTMs in oxidative stress.

