Reductase Activity Assay: The HMGR activity was performed using HMG-CoA reductase assay kit from Sigma-Aldrich with the human recombinant protein or 100 μg total cell lysates from A549 cells. Lovastatin was used as a positive control, and SAHA as a negative control. HMGR activity under defined assay conditions, containing NADPH and HMG-CoA substrate in a final volume of 0.2 mL of 100 mM potassium phosphatate buffer (120 mM KCl, 1 mM EDTA, 5 mM DTT, pH 7.4), were initiated in the presence or absence (control) of test compounds dissolved in dimethylsulfoxide (DMSO). The rates of NADPH consumption were monitored every 20 seconds, for up to 10 minutes, by spectrophotometer at 37° C. and 340 nm.
Fluorescent Activity Assay: The HDAC activity was performed using the HDAC fluorescent activity assay kit (BIOMOL, Plymouth Meeting, Pa., USA) according to the manufacturer's instructions. Briefly, recombinant proteins of HDAC1 or HDAC6 were incubated with test compounds, and HDAC reaction was initiated by addition of Fluor-de-Lys substrate. Samples were incubated for 10 min at room temperature, followed by adding developer to stop the reaction. Fluorescence was measured by fluorometric reader with excitation at 360 nm and emission at 460 nm. The HDAC activity was expressed as arbitrary fluorescence units (AFU).
Fluorescent Activity Assay: The HDAC activity was performed using the HDAC fluorescent activity assay kit (BIOMOL, Plymouth Meeting, Pa., USA) according to the manufacturer's instructions. Briefly, recombinant proteins of HDAC1 or HDAC6 were incubated with test compounds, and HDAC reaction was initiated by addition of Fluor-de-Lys substrate. Samples were incubated for 10 min at room temperature, followed by adding developer to stop the reaction. Fluorescence was measured by fluorometric reader with excitation at 360 nm and emission at 460 nm. The HDAC activity was expressed as arbitrary fluorescence units (AFU).
Fluorescent Activity Assay: The HDAC activity was performed using the HDAC fluorescent activity assay kit (BIOMOL, Plymouth Meeting, Pa., USA) according to the manufacturer's instructions. Briefly, recombinant proteins of HDAC1 or HDAC6 were incubated with test compounds, and HDAC reaction was initiated by addition of Fluor-de-Lys substrate. Samples were incubated for 10 min at room temperature, followed by adding developer to stop the reaction. Fluorescence was measured by fluorometric reader with excitation at 360 nm and emission at 460 nm. The HDAC activity was expressed as arbitrary fluorescence units (AFU).