Quantitative Native Proteomics by Capillary Zone Electrophoresis-Mass Spectrometry

ABSTRACT: Accurately measuring protein complex dynamics (i.e., composition and/or abundance changes) in cells is vital for advancing fundamental and translational research. In this work, we present a pilot study establishing capillary zone electrophoresis (CZE)-mass spectrometry (MS) based quantitative native proteomics to determine significant changes in protein complex abundance during the transition from logarithmic to stationary phase growth in Escherichia coli. The approach integrates (1) efficient and fast native-state CZE-MS to obtain the mass and signal intensity of protein complexes for label-free quantification, (2) in-source collision-induced dissociation, enabling informative fragmentation that reveals oligomeric states, and (3) denatured top-down proteomics for the identification of proteoforms, which form the protein complexes. We revealed differentially expressed protein complexes during the growth of Escherichia coli. For example, the glutamate decarboxylase beta hexamer (~317 kDa) exhibits a significantly higher abundance at the stationary phase, which aligns with its biological function. This work represents the first quantitative native proteomics study using online native CZE-MS.

INSTRUMENT(S):

ORGANISM(S): Escherichia Coli

SUBMITTER: Fei FANG  

LAB HEAD: Liangliang Sun

PROVIDER: PXD068962 | Pride | 2025-12-08

REPOSITORIES: Pride