| Aims: Inhibition of P53-MDM2/X interaction is known as an effective cancer therapy strategy. In this regard, pDI
peptide was introduced previously with the potential of targeting MDM2. In this research, the large-scale peptide
mutation screening was used to achieve the best sequence of pDI with the highest affinity for inhibition activity
against MDM2/X.
Main methods: Three mutant peptides of pDI as dual inhibitor peptides including single mutations of pDIm/4W,
pDIm/11M and double mutations of pDIdm/4W11M were presented with the high affinities to inhibit both
MDM2/X. The selected mutants were then evaluated comprehensively to confirm their ability as potent MDM2/
X inhibitors, using a theoretical simulation approach.
Key findings: MD simulations analyses confirmed their dual inhibition potential against both MDM2/X interactions with p53 protein. The developed pDIm and mainly pDIdm peptides showed stable conformations over
the simulation time with conserved secondary structure and effective interaction with MDM2/X by physical
binding such as hydrogen bonding. Besides, umbrella sampling free energy calculation indicated higher binding
energy, ΔGbinding, of pDIm-MDM2/X and pDIdm-MDM2/X compared to pDI-MDM2/X.
Significance: The optimized and improved mutant pDI, pDIdm, with more effective ΔGbinding values of −30 and
−25 kcal/mol to MDMX and MDM2, respectively, is recommended as a promising anticancer agent and suitable
candidate for experimental evaluations. |