Scaffold Hopping Method for Design and Development of Potential Allosteric AKT Inhibitors

Targeting AKT is a practical strategy for cancer therapy in many cancer types. Targeted inhibitors of AKT are attractive solutions for inhibiting the interconnected signaling pathways, like PI3K/Akt/mTOR. Allosteric inhibitors are more desirable among different classes of AKT inhibitors as they could be more specific with fewer off-target proteins. In this study, a ligand/structure-based pipeline was developed to design new allosteric AKT inhibitors by employing the core hopping method. Triciribine, a traditional allosteric AKT inhibitor was used as the template, and the FDA-approved kinase inhibitors for cancer treatment were considered as the cores. The allosteric site in the crystal structure of AKT1 was used to screen the designed compounds. The results were further evaluated using molecular docking, ADME/T analysis, molecular dynamics (MD) simulation, and binding free energy calculations. The outcomes introduced 24 newly designed inhibitors, amongst which three compounds C6, C20, and C16 showed remarkable binding affinity to AKT1. While the docking scores for triciribine was around - 8.6 kcal/mol, the docking scores of these compounds were about - 11 to - 13 kcal/mol. The MD results indicated that designed compounds target the essential residues of the PH domain and kinase domain of AKT, such as Trp80, Thr211, Tyr272, Asp274, and Asp292. Scaffold hopping is a tremendous tool for designing novel anti-cancer agents by improving already known and potential drug compounds. The designed compounds are worth to be examined by experimental investigation in vitro and in vivo.