In silico design of anti-tumor mini-protein targeting MDM2

We designed a disulfide-crosslinked mini-protein with a two-helical topology consisting of l- and d-amino acids, which was exceptionally stable in serum. Therefore, we further used it as a scaffold to design mini-proteins targeting p53 positive tumor cells. Based on bifunctional grafting, key residues from the transactivation domain of p53 and a designed unnatural amino acid were grafted into the helix constituted by l-amino acids to confer the mini-protein with MDM2 inhibitory activity. Meanwhile, ten Arg residues were introduced to improve its membrane penetrating capacity. Among the mini-proteins, UPROL-10e showed nano-molar binding affinity on MDM2 and cellular toxicity on p53 expressing HCT116 cells.