Project description:Global chromatin epigentic profiles of human cancer and NPC cell lines treated with neurodevelopmental compounds, epigenetic compounds and kinase inhibitors.
Project description:To identify confident spectra from histone peptides containing PTMs, we present a method in which one kind of modification is searched each time. We then combine the identifications of multiple search engines to obtain confident results. We find that two search engines, pFind and Mascot, identify most of the confident results. This study will be beneficial those who are interested in histone proteomics analysis.
Project description:Histone post-translational modifications (PTMs) contribute to chromatin function through their chemical properties which influence chromatin structure, and their ability to recruit chromatin interacting proteins. Nanoflow liquid chromatography coupled with high resolution tandem mass spectrometry (nanoLC-MS/MS) has emerged as the most suitable technology for global histone modification analysis due to the high sensitivity and the high mass accuracy that provide confident identification. However, the histone nanoLC-MS/MS data analysis is even more challenging due to the large number and variety of isobaric histone peptides, and the high dynamic range of histone peptide abundances. Here, we introduce EpiProfile, a software tool that discriminates isobaric histone peptides using the distinguishing fragment ions in their tandem mass spectra and extracts the chromatographic area under the curve using previous knowledge about peptide retention time. The accuracy of EpiProfile was evaluated by analysis of mixtures containing different ratios of synthetic histone peptides. In addition to label-free quantification of histone peptides, EpiProfile is flexible, and can quantify different types of isotopically labeled histone peptides. EpiProfile is much more convenient when compared to manual quantification, filling the need of an automatic and freely available tool to quantify labeled and non-labeled modified histone peptides. In summary, EpiProfile is a valuable nanoLC-MS/MS based quantification tool for histone modifications, which can also be adapted to analyze non-histone protein samples.
