CHEMBL5732281

HDAC Inhibition Assay: All histone deacetylases were purchased from BPS Bioscience. The substrates, Broad Substrate A, and Broad Substrate B, were synthesized and are now available commercially through Perkin Elmer. All the other reagents were purchased from Sigma-Aldrich. Caliper EZ reader II system was used to collect all data. HDAC inhibition assays: Compounds were tested in duplicate in a 12-point dose curve with 3-fold serial dilution starting from 33.33 μM. Purified HDACs were incubated with 2 μM carboxyfluorescein (FAM)-labeled acetylated or trifluoroacetylated peptide substrate (Broad Substrate A and B respectively) and test compound for 60 minutes at room temperature, in HDAC assay buffer that contained 50 mM HEPES (pH 7.4), 100 mM KCl, 0.01% BSA and 0.001% Tween-20. Reactions were terminated by the addition of the known pan HDAC inhibitor LBH-589 (panobinostat) with a final concentration of 1.5 μM. Substrate and product were separated electrophoretically and fluorescence intensity in the substrate and product peaks was determined and analyzed by Labchip EZ Reader. The reactions were performed in duplicate for each sample. IC50 values were automatically calculated by Origin 8 using 4 Parameter Logistic Model. The percent inhibition was plotted against the compound concentration, and the IC50 value was determined from the logistic dose-response curve fitting by Origin 8.0 software.