Assay Method Information

Assay Name:  Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) Assay
Description:  The measurement of competition of compounds of Formula (I) with F-Bak for a Bcl-2 family protein (Bcl-xL) binding site using a Time Resolved Fluorescence Resonance Energy Transfer (TR-FRET) binding assay: Test compounds were serially diluted in DMSO starting at 50 M (2x starting concentration; 10% DMSO) and 10 L transferred into a 384-well plate. Then 10 L of a protein/probe/antibody mix is added to each well at final concentrations listed in Table 1. Protein: GST-Bcl-xL; 1(nM) Probe: F-Bak (GQVGRQLAIIGDK (6-FAM)INR-amide) SEQ ID NO: 1; 100(nM) Antibody: Tb-anti-GST; 1(nM). The samples are then mixed on a shaker for 1 minute then incubated for an additional 2 hours at room temperature. For each assay plate, a probe/antibody and protein/antibody/probe mixture were included as a negative and a positive control, respectively. Fluorescence was measured on the ENVISION plate reader (Perkin Elmer) using a 340/35 nm excitation filter and 520/525 (F-Bak) and 495/510 nm (Tb-labeled anti-his antibody) emission filters. Dissociation constants (Ki) were determined using Wang's equation (Wang, Z.X. An 20 exact mathematical expression for describing competitive binding of two different ligands to protein molecule. FEBS Lett. 1995 360:111-114). The TR-FRET assay can be performed in the presence of varying concentrations of human serum (HS) or fetal bovine serum (FBS).
Affinity data for this assay
 

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