Discovery of a novel and potent KRASG12V-targeting peptide with antiproliferative activity against colorectal cancer cells.

Despite the clinical relevance of KRASG12V in colorectal cancer, KRASG12V-specific inhibitors remain limited. Through structure-based virtual screening of a 59,319-member peptide library, we identified four KRASG12V-targeting peptides, among which Peptide-1 showed the most favourable docking profile. MST assays confirmed Peptide-1 had the highest affinity among Peptides 1-4, with stronger binding to KRASG12V than to other KRAS mutants. Structural analysis, molecular dynamics simulations, and free-energy calculations indicated that Peptide-1 formed a stable and energetically favourable complex with KRASG12V through extensive hydrogen bonding and hydrophobic interactions. Peptide-1 showed favourable human serum stability and cellular NanoBRET-supported engagement with KRASG12V. Functionally, Peptide-1 displayed potent antiproliferative activity in colorectal cancer cell lines, weaker effects on normal cells and reduced efficacy after KRASG12V knockdown. In SW480 cells, Peptide-1 was associated with reduced ERK1/2 phosphorylation, p21 upregulation, and G0/G1 accumulation. Overall, these findings support further investigation of Peptide-1 as a KRASG12V-targeting peptide for colorectal cancer drug discovery.