Assay Method Information

Assay Name:  HTRF-Based EGFR Biochemical Assay
Description:  IC50 values were determined at both 1 μM and 1 mM ATP to identify both ATP competitive and non-competitive compounds. Hits were also counter-screened against wild type EGFR to evaluate the mutant selectivity. The HTRF-based screen was carried out using 1 μM ATP, and active compounds were counter-screened at 1 mM ATP and against wild type EGFR to identify those that were potentially non-ATP-competitive and mutant selective. This strategy identified several compounds of distinct chemical classes that were both selective for the L858R/T790M mutant over WT EGFR and relatively insensitive to ATP concentrations, suggesting an allosteric mechanism of action. HTRF-Based EGFR Biochemical Assays. EGFR biochemical assays were carried out using a homogeneous time-resolved fluorescence (HTRF) assay as described previously. The reaction mixtures contained 1 μM biotin-Lck-peptide substrate, wild type or mutant EGFR enzyme in reaction buffer (50 mM HEPES pH 7.1, 10 mM MgCl2, 0.01% BSA. 1 mM TCEP and 0.1 mM Na3VO4 at a final volume of 10 μL. Enzyme concentrations were adjusted to accommodate varying kinase activity and ATP concentrations (0.2-0.4 nM L858R/T790M; or 2-4 nM L858R, or 2-4 nM T790M, or 40 nM WT). All reactions were carried out at room temperature in white ProxiPlate 384-well Plus plates (PerkinElmer) and were quenched with 5 μL of 0.2 M EDTA at 60 min. Five μL per well of the detection reagent containing 2.5 ng PT66K (Cis-bio) and 0.05 μg SAXL (Prozyme) were added, and the plates were then incubated at room temperature for 1 hour and read with an EnVision plate reader.
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail