Identification of Montelukast as flavivirus NS2B-NS3 protease inhibitor by inverse virtual screening and experimental validation

Flavivirus, such as Dengue Virus (DENV) and Zika virus (ZIKV), infects millions of people and cause the death of thousands of people every year. Despite many efforts, there is no approved anti-flaviviral treatment available. In particular, some antiflavivirus compounds were investigated the cellular activities of DENV and ZIKV, but lacking the exploration of specific target enzyme, thereby resulting in the hindrance of structure-based drug design. One example is Montlukast, which was found to inhibit the replicon replication in DENV and ZIKV infected cells, with EC50 values as 1.03 mu M (DENV) and 1.14 mu M (ZIKV), while the underlying mechanism remains unclear. In our study, the inhibitory mechanisms of Montelukast against the replicon replication of DENV and ZIKV infected cells were studied by using in silico approaches including inverse virtual screening (IVS), molecular dynamics (MD) simulations and binding free energy calculation, and validated through in vitro protease assay, confirming Montelukast could bind to NS2B-NS3 proteases of DENV and ZIKV as a competitive inhibitor (IC50 for DENV: 25.65 mu M, for ZIKV: 15.57 mu M). Moreover, Montelukast has no potential off-target effect on NS2B-NS3 protease from thrombin and trypsin inhibitory assay. Overall, Montelukast may be used as a potential candidate to block NS2B-NS3 protease as well as lead for structural modification.

Automated summary

Flavivirus, including Dengue Virus (DENV) and Zika virus (ZIKV), infects and kills millions of people every year, but there is no approved treatment available. In this study, we investigated the inhibitory mechanisms of Montelukast, an existing drug, against the replication of DENV and ZIKV. Through computational methods and in vitro experiments, we found that Montelukast can bind to NS2B-NS3 proteases of DENV and ZIKV and act as a competitive inhibitor. This research provides new insights for the development of potential antiviral drugs.