Here a structure-based pharmacophore search and docking simulation are presented in order to filter our in-house library which contains 1035 compounds to find novel scaffolds that inhibit Mdm2 and Mdmx concomitantly. Afterwards, fluorescence polarization binding assay was used to obtain inhibition constant of final compounds.
Thirty two ligands were introduced to bioassay as a result of in-silico methods. Twelve of them inhibit both proteins with almost balanced Ki value ranging from 18 to 162 μM for Mdm2 and 18 to 233 μM for Mdmx. It was observed that all compounds fill Phe19 and Trp23 pockets of Mdm2/x binding sites and form a hydrogen bond with Trp23 pocket's neighbor amino acids in a manner similar to p53 protein. Additionally, it was concluded that Trp23 pocket of Mdmx has a bigger hydrophobic volume comparing with the one of Mdm2.
Three structure–activity relationship patterns are supposed which one of them presents usefulness features and can be used in future studies. This study presents first qualitative SAR for dual inhibitors against Mdm2/x.