Fig. 1.

Identification of small molecule enhancers of β-catenin:β-TrCP interaction. a β-TrCP complex was titrated against 5 nM BODIPY-TMR-labeled β-catenin peptide (residues 17–48) of various phosphorylation status and binding was monitored by fluorescence polarization. Binding affinities were estimated by curve fitting to a one-site binding model. Circled on the pSer33/Ser37 β-catenin binding curve is the β-TrCP concentration that results in 20% binding saturation, which was used in the HTS. b Binding enhancement for all compounds screened in the HTS using the FP assay. Each dot represents an individual compound, with NRX-1532 highlighted. c Chemical structure of the enhancers, NRX-1532 and NRX-1933. d Enhancement of pSer33/Ser37 β-catenin peptide binding to β-TrCP with increasing concentrations of NRX-1532. In each assay, the concentration of either β-TrCP or β-catenin was adjusted to obtain 20% binding saturation in the absence of compound. Shown is a representative experiment, values reported are averages