Histone H3 and H4 residue-specific PTMs quantified by mass spectrometry. (a) Total ion chromatogram and full MS spectrum of propionylated histone peptides used for quantification from an HP1β ChIP; ChIP elution D0 labeled (black), and the control ChIP input D5 labeled (red). Full MS spectrum of peptides shown; H3K9me3K14un, H3K9me1K14un, H4K5unK8unK12acK16ac, H3K18unK23me1 and H3K79me3. (b) Quantification of the degree of acetylation of the histone H4 peptide (amino acids 4 to 17, GKGGKGLGKGGAKR). Values in the table are the total percentage of each acetylated form and the heatmap is a representation of the fold change of the specified ChIP/Input in (log2) scale. (c) Heatmap depicting all modifications quantified on the histone H3 and H4 proteins. Values used to generate the heatmap are found in Additional file 2. The heatmap was generated with the fold change values of each PTM for each specified ChIP/Input in (log2) scale.
LeRoy et al. Genome Biology 2012 13:R68 doi:10.1186/gb-2012-13-8-r68