Effect of Biomolecular Conformation on Docking Simulation: A Case Study on a Potent HIV-1 Protease Inhibitor

Human immunodeficiency virus infection / acquired immunodeficiency syndrome (HIV/AIDS) is a disease pertained to the human immune system. Given its crucial role in viral replication, HIV-1 protease (HIV-1 PR) is a prime therapeutic target in AIDS therapy. In this regard, the dynamic aspects of ligand-enzyme interactions may indicate an important role of conformational variability in HIV-1 PR inhibitor/drug design. In the present contribution, the effect of HIV-1 PR flexibility (multiple crystallographic structures of HIV-1 PR) on binding to the Amprenavir was elucidated via an ensemble docking approach. Molecular docking studies were performed via advanced AutoDock4.2 software. Ensemble docking of Amprenavir into active site of various conformations of HIV-1 PR predicted different interaction modes/energies. Analysis of binding factors in terms of docking false negatives/positives revealed a determinant role of enzyme conformational variation in prediction of optimum induced fit (PDB ID: 1HPV). It was also known that deviation of ligand from its minimum energy conformation would not be sufficiently supportive in prediction of HIV-1 PR targeted docking results. The outcomes of this study demonstrated that conformation of receptor may significantly affect the accuracy of docking/binding results in rational design of anti HIV-1 PR agents. Furthermore; some strategies to re-score the docking results in HIV-1 PR targeted docking studies were proposed.