CHEMBL5734210

In Vitro Measurements of porcine D-Amino Acid Oxidase (DAAO) Activities: The pkDAAO (porcine kidney DAAO) activity was measured by using D-Proine as a substrate to produce hydrogen peroxide (H2O2). The produced H2O2 would be oxidized by peroxidase, and the produced free radicals would further react with 1,2-Phenylenediamine (OPD) reagent. The reaction product had an absorbance on 450 nm. The OD450 would be measured to represent the activity of pkDAAO. All compounds were dissolved in DMSO. Each compound was diluted with DMSO in 3 or 4-fold serial dilution to create a 9-point dose response curve. Each sample was added in triplicate, 10 μL/well, into 96-well assay microplate. Positive control wells were added with 10 μL of DMSO. The diluted compounds were incubated with pkDAAO in dark for 10 minutes and then reacted with D-Proline. The final reaction mixture was composed of 0.01 U/mL pkDAAO, 0.03% OPD, 25 U/mL HRP and 40 mM D-Proline in PBS. The reaction plates were then incubated in the dark at room temperature. The OD450 absorbance readout was detected at 0 and 20 minute by Molecular Device Spectra Max Plus reader. The percentage of inhibition values for each well were calculated with the following equation:The percentage of inhibition=(OD450sample, 20 min−OD450sample, 0 min)/(OD450DMSO, 20 min−OD450DMSO, 0 min)×100%The nonlinear curve fitting model in GraphPad Prism 5 was used to calculate IC50 value for each compound.