Fluorescence Polarization (FP) Based Competitive Assay: Binding affinities of the present compounds to XIAP linker-BIR2-BIR3 (residues 120-356), cIAP1-BIR3 (residues 253-363), and cIAP-2 BIR3 (residues 238-349) proteins were determined by fluorescence polarization (FP) based competitive assays. For cIAP-1 BIR3 and cIAP-2 BIR3 assays, a fluorescently labeled Smac mimetic (Smac-2F) was used as the fluorescent probe. The Kd values of Smac-2F to cIAP-1 BIR3 and cIAP-2 BIR3 were determined by monitoring the total fluorescence polarization of mixtures composed with the fluorescent probe at a fixed concentration and proteins with increasing concentrations up to full saturation. Fluorescence polarization values were measured using the Infinite M-1000 plate reader (Tecan U.S., Research Triangle Park, N.C.) in Microfluor 2 96-well, black, round-bottom plates (Thermo Scientific). To each well, 1 nM of SMAC-2F and increasing concentrations of protein were added to a final volume of 125 ul in the assay buffer (100 mM potassium phosphate, pH 7.5).
Fluorescence Polarization (FP) Based Competitive Assay: Binding affinities of the present compounds to XIAP linker-BIR2-BIR3 (residues 120-356), cIAP1-BIR3 (residues 253-363), and cIAP-2 BIR3 (residues 238-349) proteins were determined by fluorescence polarization (FP) based competitive assays. For cIAP-1 BIR3 and cIAP-2 BIR3 assays, a fluorescently labeled Smac mimetic (Smac-2F) was used as the fluorescent probe. The Kd values of Smac-2F to cIAP-1 BIR3 and cIAP-2 BIR3 were determined by monitoring the total fluorescence polarization of mixtures composed with the fluorescent probe at a fixed concentration and proteins with increasing concentrations up to full saturation. Fluorescence polarization values were measured using the Infinite M-1000 plate reader (Tecan U.S., Research Triangle Park, N.C.) in Microfluor 2 96-well, black, round-bottom plates (Thermo Scientific). To each well, 1 nM of SMAC-2F and increasing concentrations of protein were added to a final volume of 125 ul in the assay buffer (100 mM potassium phosphate, pH 7.5).
Fluorescence Polarization (FP) Based Competitive Assay: Binding affinities of the present compounds to XIAP linker-BIR2-BIR3 (residues 120-356), cIAP1-BIR3 (residues 253-363), and cIAP-2 BIR3 (residues 238-349) proteins were determined by fluorescence polarization (FP) based competitive assays. For cIAP-1 BIR3 and cIAP-2 BIR3 assays, a fluorescently labeled Smac mimetic (Smac-2F) was used as the fluorescent probe. The Kd values of Smac-2F to cIAP-1 BIR3 and cIAP-2 BIR3 were determined by monitoring the total fluorescence polarization of mixtures composed with the fluorescent probe at a fixed concentration and proteins with increasing concentrations up to full saturation. Fluorescence polarization values were measured using the Infinite M-1000 plate reader (Tecan U.S., Research Triangle Park, N.C.) in Microfluor 2 96-well, black, round-bottom plates (Thermo Scientific). To each well, 1 nM of SMAC-2F and increasing concentrations of protein were added to a final volume of 125 ul in the assay buffer (100 mM potassium phosphate, pH 7.5).