Isothermal Titration Calorimetry. ITC experiments were conducted on an Affinity ITC instrument (TA Instruments, New Castle, DE, USA) at 25 °C with a stirring rate of 75 rpm. Nurr1 LBD protein (15-20 μM) in buffer (20 mM Tris, pH 7.5, 100 mM NaCl, 5% glycerol) containing 5% DMSO was titrated with the test compounds (60-100 μM in the same buffer containing 1-4% DMSO) in 21-26 injections (1 × 1 µL and 20-25 × 4 μL) with an injection interval of 150 s. As control experiments, the test compounds were titrated to the buffer, and the buffer was titrated to the Nurr1 LBD protein under otherwise identical conditions. The heats of the compound-protein titrations were corrected with the heats of the compound-buffer titrations and analyzed using NanoAnalyze software (version 3.11.0, TA Instruments) with independent binding models.