Development of a fluorogenic probe with a transesterification switch for detection of histone deacetylase activity.

Histone deacetylases (HDACs) are key enzymatic regulators of many cellular processes such as gene expression, cell cycle, and tumorigenesis. These enzymes are attractive targets for drug development. However, very few simple methods for monitoring HDAC activity have been reported. Here, we have developed a fluorogenic probe, K4(Ac)-CCB, which consists of the histone H3 peptide containing acetyl-Lys and a coumarin fluorophore with a carbonate ester. By the simple addition of the probe to a HDAC solution, enzyme activity was clearly detected through spontaneous intramolecular transesterification, which renders the probe fluorescent. In addition, K4(Ac)-CCB can be applied to the evaluation of HDAC inhibitor activity. This is the first report to demonstrate the monitoring of HDAC activity by using a one-step procedure. Thus, our novel fluorogenic probe will provide a powerful tool for epigenetic research and the discovery of HDAC-targeted drugs.