Rational Design of a Novel Anti-Cancer Hybrid Peptide Inhibiting the PI3K/AKT and CDK2 Signaling Pathways using Molecular Dynamics Simulations.

Melittin (MLT) peptide is considered due to targeting key proteins involved in apoptosis pathways to suppress tumor progression. However, the clinical application of MLT is limited due to its high cytotoxicity and poor cellular permeability. In this study, a hybrid peptide (AM1) derived from MLT and Aurein 1.2(Aur1.2) with modified properties was designed to enhance its therapeutic efficacy. A truncated form of MLT comprised of the last five C-terminal amino acids, was fused to a modified truncated Aur 1.2, in which Glycine was replaced with Tyrosine to enhance anticancer properties. Based on docking results, AM1 indicated specific interaction with the AKT1 protein in, Glu278, Asp292, and Thr308 residues. Also, it showed a specific interaction with residues Glu51, Asp86, and Asp145 in CDK2 protein. According to VMD results, the N-terminal region of the Aur1.2 peptides, excluding the first three amino acids, maintained its α-helical structure up to 50 ns. However, at 100 ns, partial structural alterations were observed, such that only amino acids 7 to 12, corresponding to the Aur region, retained their α-helical conformation. RMSD and RMSF analyses revealed no significant or undesirable fluctuations throughout the simulation of 200 ns of molecular dynamics. The RMSD values for the AM1 peptide ranged between 0.00048 and 0.64 nm and reached stability after 140 ns. Additionally, RMSD and RMSF analyses confirmed the stability of the AKT1-AM1 and CDK2-AM1 complexes. DSSP analysis indicated that the secondary structures of both complexes remained stable throughout the simulations. In addition, MM/GBSA calculations demonstrated that the binding of AM1 to both proteins is thermodynamically favorable, indicating stable and effective interactions. Furthermore, CG simulation results demonstrated the ability of the AM1 peptide to penetrate the DOPC-DOPS model membrane. In silico results suggest that AM1 is a candidate inhibitor of the PI3K/AKT and CDK2 signaling pathways, which are crucial in cancer progression; however, this finding still needs experimental validation.