Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) Assay: The inhibition constant (Ki) is the dissociation constant of an enzyme-inhibitor complex or a protein/small molecule complex, wherein the small molecule is inhibiting binding of one protein to another protein or peptide. Where the Ki for a compound is represented as > (greater than) a certain numerical value, it is intended to mean that the binding affinity value (e.g., for Bcl-XL) is greater than the limits of detection of the assay used. Where the binding selectivity ratio for a compound is represented as > (greater than) a certain numerical value, it is intended to mean that the selectivity of a particular compound for Bcl-2 over Bcl-XL is at least as great as the number indicated. Where the Ki for a compound is represented as < (less than) a certain numerical value, it is intended to mean that the binding affinity value (e.g., for Bcl-2) is lower than the limit of detection of the assay used. Inhibition constants were determined using Wang's equation (Wang Z-X).
Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) Assay: The inhibition constant (Ki) is the dissociation constant of an enzyme-inhibitor complex or a protein/small molecule complex, wherein the small molecule is inhibiting binding of one protein to another protein or peptide. Where the Ki for a compound is represented as > (greater than) a certain numerical value, it is intended to mean that the binding affinity value (e.g., for Bcl-XL) is greater than the limits of detection of the assay used. Where the binding selectivity ratio for a compound is represented as > (greater than) a certain numerical value, it is intended to mean that the selectivity of a particular compound for Bcl-2 over Bcl-XL is at least as great as the number indicated. Where the Ki for a compound is represented as < (less than) a certain numerical value, it is intended to mean that the binding affinity value (e.g., for Bcl-2) is lower than the limit of detection of the assay used. Inhibition constants were determined using Wang's equation (Wang Z-X).
Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) Assay: Representative compounds were serially diluted in dimethyl sulfoxide (DMSO) starting at 50 uM (2x starting concentration; 10% DMSO) and 10 uL were transferred into a 384-well plate. Then 10 uL of a protein/probe/antibody mix was added to each well at final concentrations listed in TABLE 1. Protein:GST-Bcl-2, Probe: F-Bak Peptide Probe Acetyl-GQVGRQLAIIGDK(6-FAM)INR-amide(SEQ ID NO: 1), Protein(nM): 1, Probe (nM): 100, Antibody: Tb-anit-GST, Antibody (nm): 1. The samples are then mixed on a shaker for 1 minute and incubated for an additional 3 hours at room temperature. For each assay, the probe/antibody and protein/probe/antibody were included on each assay plate as negative and positive controls, respectively. Fluorescence was measured on the ENVISION plate reader (Perkin Elmer) using a 340/35 nm excitation filter and 520/525 (F-Bak peptide) and 495/510 nm (Tb-labeled anti-Histidine antibody) emission filters.