Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158-2517, USA.
Mol Cell Proteomics. 2010 May;9(5):824-37. doi: 10.1074/mcp.M900569-MCP200. Epub 2010 Feb 4.
Epigenetic regulation of chromatin is dependent on both the histone protein isoforms and state of their post-translational modifications. The assignment of all post-translational modification sites for each individual intact protein isoform remains an experimental challenge. We present an on-line reversed phase LC tandem mass spectrometry approach for the separation of intact, unfractionated histones and a high resolution mass analyzer, the Orbitrap, with electron transfer dissociation capabilities to detect and record accurate mass values for the molecular and fragment ions observed. From a single LC-electron transfer dissociation run, this strategy permits the identification of the most abundant intact proteins, determination of the isoforms present, and the localization of post-translational modifications.
染色质的表观遗传调控既依赖于组蛋白蛋白亚型，也依赖于其翻译后修饰的状态。为每个单独的完整蛋白亚型分配所有翻译后修饰位点仍然是一个实验挑战。我们提出了一种在线反相 LC 串联质谱方法，用于分离完整的、未分级的组蛋白，以及具有电子转移解离功能的高分辨率质量分析仪——轨道阱，以检测和记录所观察到的分子离子和碎片离子的精确质量值。通过单次 LC-电子转移解离运行，该策略允许鉴定最丰富的完整蛋白质，确定存在的亚型，并定位翻译后修饰。
