ABSTRACT
CC chemokine receptor 5 (CCR5), a member of G protein-coupled receptors (GPCRs), not only plays a significant role in inflammatory responses, but also correlates with HIV-1 infection and cancer progression. Recently, blocking of CCR5 has been considered as an effective strategy in HIV-1/cancers therapy. So far, only Maraviroc has been approved by FDA in 2007, while the other CCR5 inhibitors have failed in their clinical trials. In this study, a highly selective structure-based pharmacophore model was constructed, validated, and applied for virtual screening to retrieve novel CCR5 inhibitors from NCI database. Finally, one potential CCR5 inhibitor candidate, NSC13165, was identified after molecular docking, molecular dynamics (MD) simulations, binding free energy analyses and ADMET prediction. Docking and MD simulation results not only suggested that NSC13165 reserves the common binding mode of the most known CCR5 inhibitors, but also provided important insights toward the allosteric inhibition mechanism of CCR5. The results of binding free energy analyses indicated that the binding affinity of NSC13165 is much better than that of Maraviroc and that van der Waals interaction is the key driving force during the binding process. ADMET prediction suggested that NSC13165 exhibits very low risk of causing lethal side effects. Altogether, our results strongly suggest that NSC13165 has great potential to serve as a novel CCR5 inhibitor, which may be further tested in vitro/in vivo as a drug target for HIV-1/cancers therapy or be used as a lead compound for improving its efficacy through chemical modifications.