| Assay Method Information | |
| | Scintillation Proximity Assay (SPA) |
| Description: | Assays were run using 384-well plates (781207/Greiner) in which one column was designated as the high signal (no inhibition) control, and contained DMSO with no test compound, and another column was designated as the low signal control (maximal inhibition), and contained no protein. Serial dilutions of compounds to be tested were added to the assay plate (resulting in duplicate 11-point dose response with semi-log compound dilutions from 50 μM to 0.5 nM or from 5 μM to 0.05 nM for the most potent compounds). A 1/20 isotopic dilution of labeled (Compound B) and non-labeled covalent (Compound A) probe was prepared and added to all wells on the plate. The reaction was started by addition of KRasG12C (M1-K169, biotinylated on the N-terminus) to the compounds and incubated for 2 hours with continuous agitation allowing for full modification of KRasG12C with probe or test compounds. Final concentrations in an assay volume of 40 μL were 10 nM KRasG12C, 25 nM radio-ligand and 475 nM unlabelled ligand. The assay buffer contained 20 mM Tris-HCl pH 7.5 (Invitrogen), 150 mM NaCl (Sigma Aldrich), 0.1 mM MgCl2 (Sigma Aldrich), and 0.01% Tween-20 (Sigma Aldrich). Following addition of 50 μL of a 400 μg/ml. suspension of streptavidin-coated YSi beads (Perkin Elmer), plates were incubated for a further 30 min with continuous agitation before reading the plates on a scintillation counter (Topcount NXT 384 (Packard). |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |