Characterization of Complete Histone Tail Proteoforms Using Differential Ion Mobility Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 89; no. 10; pp. 5461 - 5466
• Main Authors: Shliaha, Pavel V, Baird, Matthew A, Nielsen, Mogens M, Gorshkov, Vladimir, Bowman, Andrew P, Kaszycki, Julia L, Jensen, Ole N, Shvartsburg, Alexandre A
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16.05.2017
• Subjects: Acetylation; Analytical chemistry; Chemistry; Chromatin; dissociation; Electron transfer; Functional anatomy; gases; histones; Ionic mobility; Methylation; Mobility; nucleosomes; Peptides; Phase separation; Phosphorylation; Post-translation; post-translational modification; Proteins; Proteomics; Residues; Spectrometry; Spectroscopy; Structure-function relationships; Translation
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.7b00379

Histone proteins are subject to dynamic post-translational modifications (PTMs) that cooperatively modulate the chromatin structure and function. Nearly all functional PTMs are found on the N-terminal histone domains (tails) of ∼50 residues protruding from the nucleosome core. Using high-definition differential ion mobility spectrometry (FAIMS) with electron transfer dissociation, we demonstrate rapid baseline gas-phase separation and identification of tails involving monomethylation, trimethylation, acetylation, or phosphorylation in biologically relevant positions. These are by far the largest variant peptides resolved by any method, some with PTM contributing just 0.25% to the mass. This opens the door to similar separations for intact proteins and in top-down proteomics.