CHEMBL5733201

PKR KinaseGlo Assay: Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Massachusetts, USA). The % inhibition for the compounds is calculated using ATP only (100% inhibition) and PKR+ATP (0% inhibition). IC50 values are determined by plotting % activity versus inhibitor concentration. Curves are fitted using Activity base XLfit (IDBS, UK) using the formula— 4 Parameter Logistic Model.