High-Throughput Strategy to Identify Inhibitors of Histone-Binding Domains

Many epigenetic proteins recognize the posttranslational modification state of chromatin through their histone-binding domains and thereby recruit nuclear complexes to specific loci within the genome. A number of these domains have been implicated in cancer and other diseases through aberrant binding of chromatin; therefore, identifying small molecules that disrupt histone binding could be a powerful mechanism for disease therapy. We have developed a high-throughput assay for the detection of histone peptide–domain interactions utilizing AlphaScreen technology. Here, we describe how the assay can be first optimized and then performed for high-throughput screening of small molecule-binding inhibitors. We also describe strategies for biochemical validation of small molecules identified.