Fig. 4
Ligand binding affinities and the influence of ligand on H12 mobility. a, Competitive binding affinity assay of compounds binding to ERα LBD. Experimental data points are mean + /− s.e.m. of triplicate samples in a representative experiment. Curves were fit using a one-site fit-log model (IC50) in GraphPad Prism with R2 of fits were ≥ 0.97. The IC50 values were 6.71 ± 0.06 nM for E2, 10.46 ± 0.06 nM for 4-OHT, 26.88 ± 0.07 nM for Fulv, 14.3 ± 0.06 nM for OP-1154, 6.13 ± 0.06 nM for OP-1156, and 7.03 ± 0.05 nM for OP-1074. b, Measured half-lives of ERα-ligand complexes in a trypsin-coupled fluorescence polarization assay of ERα LBD helix 12 mobility. *Denotes statistical significance between bars (**** for p < 0.0001, *** for p < 0.0001–0.001) using one-way ANOVA analysis. No significant differences were observed between Apo and fulvestrant or OP-1154 and OP-1156. Experimental data points are mean + /− s.d. of triplicate samples in a representative experiment
