Environment-sensitive turn-on fluorescent probes for p53–MDM2 protein–protein interaction

A series of probes with a turn-on switch for the p53–MDM2 protein–protein interaction were developed. After careful evaluation, these small molecule fluorescent probes exhibited high practical activity and selectivity in vitro and in cellulo. In particular probe 10, which had a Ki value of 0.03 μM, displayed much better binding affinity compared to the positive control Nutlin-3, which had a Ki value of 0.23 μM. These no-wash environment-sensitive turn-on fluorescent probes have been successfully applied to imaging p53–MDM2 interaction in the human lung cancer cell line A549 (wild-type p53) at the micromolar level. Therefore, these fluorescent probes are expected to be used in drug screening and cell staining in p53–MDM2 fields, as well as in pathological and physiological studies of the p53–MDM2 interaction.