Characterization of complete histone tail proteoforms using differential ion mobility spectrometry

Click on the DOI link to access the article (may not be free).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 similar to 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 rnonomethylation, 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.VILLUM Foundation to the VILLUM Center for Bioanalytical Sciences at University of Southern Denmark (O.N.J.), a Lundbeck Foundation Postdoctoral Fellowship (P.S.), and NIH COBRE (P30 GM110761) and NSF CAREER (CHE-1552640) grants (A.S.). A.S