Middle-Down Proteomic Analyses with Ion Mobility Separations of Endogenous Isomeric Proteoforms

Pavel V Shliaha, Vladimir Gorshkov, Sergey I Kovalchuk, Veit Schwämmle, Matthew A Baird, Alexandre A Shvartsburg, Ole N Jensen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Biological functions of many proteins are governed by post-translational modifications (PTMs). In particular, the rich PTM complement in histones controls the gene expression and chromatin structure with major health implications via a combinatoric language. Deciphering that "histone code" is the great challenge for proteomics given an astounding number of possible proteoforms, including isomers with different PTM positions. These must be disentangled on the top- or middle-down level to preserve the key PTM connectivity, which condensed-phase separations failed to achieve. We reported the capability of ion mobility spectrometry (IMS) methods to resolve such isomers for model histone tails. Here, we advance to biological samples, showing middle-down analyses of histones from mouse embryonic stem cells via online chromatography to fractionate proteoforms with distinct PTM sets, differential or field asymmetric waveform IMS (FAIMS) to resolve the isomers, and Orbitrap mass spectrometry with electron transfer dissociation to identify the resolved species.

Original languageEnglish
JournalAnalytical chemistry
Volume92
Issue number3
Pages (from-to)2364-2368
ISSN0003-2700
DOIs
Publication statusPublished - 4. Feb 2020

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