p53 DNA-Binding Domain

Missense mutations in the p53 DNA-binding domain (DBD) often destabilize its structure, exposing an aggregation-nucleating subdomain (residues 251-258), which prompts the protein to self-assemble into inactive amyloid-like aggregates. ADH-6 as a potent amyloid inhibitor that effectively abrogates this self-assembly and dissociates pre-formed mutant p53 aggregates in human cancer cells. This dissociation restores the transcriptional activity of p53, triggering tumor-suppressive pathways such as cell cycle arrest and apoptosis. ¹⁵N-¹H HSQC NMR spectra elucidated the molecular basis of the rescue process, identifying five clusters on the surface of p53 DBD where ADH-6 interaction occurs. Notably, NMR data confirmed that ADH-6 interacts directly with the aggregation-nucleating subdomain of p53 DBD (specifically residue L257) and induces local mobility changes that shift the conformational equilibrium toward the DBD functional, soluble state. By targeting multiple regions of the DBD, ADH-6 acts as a structural stabilizer that prevents the protein from sampling the intermediates leading to amyloid formation.