Naturally occurring constrained peptides are frequently used as scaffolds for bioactive peptide grating due to their high stability. Here, we used in silico methods to design several constrained peptides comprising a scorpion toxin scaffold, a MDM2 bi...
Naturally occurring constrained peptides are frequently used as scaffolds for bioactive peptide grating due to their high stability. Here, we used in silico methods to design several constrained peptides comprising a scorpion toxin scaffold, a MDM2 binding epitope, and a cluster of positively charged residues. The designed peptides displayed varied binding affinity to MDM2 despite differing by only one or two residues. One of the peptides, SC426, had nanomolar binding affinity (KD=6.6±2.6 nm) to MDM2, and exhibited stronger inhibitory activity on the proliferation of HCT116 cells (p53‐wild type) and SW480 cells (p53‐mutant) than that of nutlin‐3a. Binding mode analysis of the designed peptide at MDM2 suggests that the conserved “FWL” epitope was buried in the hydrophobic binding pocket, and the residues located at the periphery of the binding site contributed to the high binding affinity of SC426. Overall, in silico design of miniproteins with therapeutic potential through epitope grafting to the naturally occurring constrained peptide is an effective strategy.
From scorpions to scaffolds: MDM2 ubiquitination mediates degradation of the cancer‐protective transcription factor p53. With the goal of reducing MDM2‐mediated degradation of the p53 transcription factor, novel constrained miniproteins were designed in silico. Designed by epitope grafting onto the scaffold of a naturally occurring scorpion toxin, these miniproteins show similar binding and antiproliferative activity to nutlin‐3a.