CHEMBL5738092

Fluorescence Polarization Binding Assay: Table 3: The FP assay was then adapted for HTS and used to screen 120,000 small molecule library for compounds that displaced probe 5 from the T4 binding of TTR. The FP assay was performed in 384-well plate using very low concentration of probe 5 (1.5 nM) and TTR (50 nM) in a 10 μL assay volume. A detergent (0.01% Triton-X100) was added to the assay buffer to avoid any false positive hits from promiscuous, aggregate-based inhibitors. The assay demonstrated robust performance, with a very good dynamic range (70-230 mP) and a Z′ factor in the range of 0.57-0.78 (FIGS. 4A and 4B). Hits were defined as compounds that resulted in at least 50% decrease in fluorescence polarization and demonstrated relative fluorescence between 70 and 130%. Many fluorescence quenchers and enhancers having less than 70% and greater than 130% total fluorescence relative to a control, respectively, were excluded from the hit list. 200 compounds were designated as positive hits (0.167% hit rate). The 200 hits were then evaluated in a dose-response manner and their IC50 (compound concentration that resulted in 50% decrease in the FP signal) values were determined. Among the 200 compounds screened, 33 compounds showed a dose-response effect on the FP and displayed IC50≤10 μM.