CHEMBL5739436

PDGFRα Kinase Assay: The activity of unphosphorylated PDGFRα kinase was determined spectroscopically using a coupled pyruvate kinase/lactate dehydrogenase assay that continuously monitors the ATP hydrolysis-dependent oxidation of NADH (e.g., Schindler et al. Science (2000) 289: 1938-1942). Assays were conducted in 384-well plates (100 μL final volume) using 11.7 nM PDGFRα (DeCode Biostructures), 1.5 units pyruvate kinase, 2.1 units lactate dehydrogenase, 1 mM phosphoenol pyruvate, 0.28 mM NADH, 0.7 mg/mL PolyEY and 1 mM ATP in assay buffer (100 mM Tris, pH 7.5, 15 mM MgCl2, 0.5 mM DTT, 0.1% octyl-glucoside, 0.002% (w/v) BSA, and 0.002% Triton X-100). Inhibition of PDGFRα was measured by adding serial diluted test compound (final assay concentration of 1% DMSO). A decrease in absorption at 340 nm was monitored continuously for 6 hours at 30° C. on a multi-mode microplate reader (BioTek). The reaction rate was calculated using the 2-3 h time frame. The reaction rate at each concentration of compound was converted to percent inhibition using controls (i.e. reaction with no test compound and reaction with a known inhibitor) and IC50values were calculated by fitting a four-parameter sigmoidal curve to the data using Prism (GraphPad software).