Assay Method Information

Assay Name:  RET Enzyme Assay
Description:  Compounds of formulas I, la to lx, Ila to IIx, and/or Illa to IIIx are screened for their ability to inhibit wildtype, V804M, and G810S mutant RET kinase using CisBio s HTRF KinEASE -TK assay technology. N-terminal GST tagged recombinant human RET cytoplasmic domain (aa 658-end) from Eurofins (1.25 nM RET; Catalog No. 14-570M) or N-terminal GST tagged recombinant human V804M mutant RET cytoplasmic domain (aa 658-end) from Millipore (1.25 nM enzyme; Catalog No. 14-760) or N-Terminal GST-tagged recombinant human G810S (aa-658-end) (1.25 nM Enzyme; produced in insect cells) is incubated with 62.5 nM TK-substrate biotin (CisBio, part of Catalog No. 62TK0PEC) and 1 mM ATP along with test compound (0.4% final DMSO in the assay) in a IX Cisbuio enzymatic buffer consisting of 1 nM DTT, 5 mM MgCh, 0.04% BSA and 0.05% Tween20 in a volume of 10 pL. Compounds are typically prepared in a threefold serial dilution in DMSO and added to the assay to give the appropriate final concentration. After a 40-60 min (40 min for V804M, 60 min for WT and G810S) incubation at 22 °C, the reaction is quenched by adding quench solution (10 pL) containing 7.8 nM Streptavidine-XL665 and 0.5X TK-ab-Cryptate in HTRF detection buffer (all from CisBio, part of Cat. No. 62TK0PEC). After a 60-80 min incubation (60 minutes for WT, 80 minutes for V804M and G810S) at 22 °C, the extent of reaction is determined using a PHERastar plate reader via HTRF detection at excitation/emission 337/665 nm. Percent of inhibition is calculated with 0% inhibition referring to control conditions containing no compound (0.4% DMSO only) and 100% inhibition represented by conditions containing no enzyme. The % inhibition values are fit to a 4 parameter logistic curve, and the determined IC5o value is defined as the estimated concentration of inhibitor at the inflexion point of the fitted curve.
Affinity data for this assay
 

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