CHEMBL5733436

Enzyme Inhibition: The HDAC activity inhibition assay was performed as follows to determine the ability of a test compound to inhibit HDAC enzymatic activity. Serial dilutions of HDAC inhibitors were prepared in HDAC assay buffer (25 mM Tris/HCl, pH 8.0, 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl2, pH 8) in 96-well assay plates (Fisher scientific, #07-200-309) and were pre-incubated for 2 hours at room temperature in the presence of 1254 μg/ml BSA and purified HDAC1 (BPS Bioscience, San Diego, Calif., #50051), HDAC2 (BPS Bioscience, #50053), or HDAC3/NcoR2 (BPS Bioscience, #50003) at concentrations of 1.25, 1.32, and 0.167 vg/mL, respectively. Following pre-incubation, Fluor-de-Lys™ substrate (Enzo Life Sciences, Plymouth Meeting, Pa., BML-KI104-0050) was added to a final concentration of 10 μM and plates were further incubated for 30 minutes at room temperature. The enzymatic reaction was stopped by addition of Trichostatin A (Sigma-Aldrich, St Louis, Mo., #T8552, final concentration: 100 nM) and trypsin (MP Biomedicals, Solon, Ohio, #02101179) was added to reach a final concentration of 100 μg/mL. After a 15 minute incubation at room temperature, fluorescence was recorded using a Spectramax M2 fluorometer (Molecular Devices, Sunnyvale, Calif.) with excitation at 365 nm and emission at 460 nm.