Assay Method Information

Assay Name:  Mdm2-p53 Inhibition AlphaScreen
Description:  This assay is used to determine whether the compounds inhibit the p53-MDM2 interaction and thus restore p53 function.15 μL of compound in 20% DMSO (serial pre-dilutions of compound are done in 100% DMSO) is pipetted to the wells of a white OptiPlate-96 (PerkinElmer). A mix consisting of 20 nM GST-MDM2 protein (aa 23-117) and 20 nM biotinylated p53 wt peptide (encompassing aa 16-27 of wt human p53, amino acid sequence QETFSDLWKLLP-Ttds-Lys-Biotin, molecular weight 2132.56 g/mol) is prepared in assay buffer (50 mM Tris/HCl pH 7.2; 120 mM NaCl; 0.1% bovine serum albumin (BSA); 5 mM dithiothreitol (DTT); 1 mM ethylenediaminetetraacetic acid (EDTA); 0.01% Tween 20). 30 μL of the mix is added to the compound dilutions and incubated for 15 min at rt while gently shaking the plate at 300 rounds per minute (rpm). Subsequently, 15 μL of premixed AlphaLISA Glutathione Acceptor Beads and AlphaScreen Streptavidin Donor Beads from PerkinElmer (in assay buffer at a concentration of 10 μg/mL each) are added and the samples are incubated for 30 min at rt in the dark (shaking 300 rpm). Afterwards, the signal is measured in a PerkinElmer Envision HTS Multilabel Reader using the AlphaScreen protocol from PerkinElmer.Each plate contains negative controls where biotinylated p53-peptide and GST-MDM2 are left out and replaced by assay buffer. Negative control values are entered as low basis value when using the software GraphPad Prism for calculations. Furthermore, a positive control (5% DMSO instead of test compound; with protein/peptide mix) is pipetted. Determination of IC50 values are carried out using GraphPad Prism 3.03 software (or updates thereof).
Affinity data for this assay
 

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