Peptide mass mapping of acetylated isoforms of histone H4 from mouse lymphosarcoma cells treated with histone deacetylase (HDACs) inhibitors.

The acetylated isoforms of histone H4 from mouse lymphosarcoma cells treated with HDAC inhibitors trichostatin A (TSA) and depsipeptide (DDP) were separated by acetic acid urea-polyacrylamide gel electrophoresis (AU-PAGE), in-gel digested, and analyzed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). The acetylation pattern of histone H4 in mouse lymphosarcoma cells induced by TSA was established in which acetylation initially occurred at K16 followed by K12 and then K8 and/or K5. An identical order of acetylation was found for cells treated with DDP.