Design, Synthesis, and in-vitro Protease Inhibition Assay of Linear Pentapeptides as Potential Dengue Virus NS2B/NS3 Protease Inhibitors

Nowadays dengue virus infection (DENV) is one of the major health complications in the world. Although DENV is an old and common disease, unfortunately, until now, there are no specific relevant treatments available for it. This study, therefore, aimed to design, as well as synthesize selective peptide inhibitors, and investigate their activity by in-vitro NS2B/NS3 protease inhibition assay. The design of the peptide ligands was based on studying the interactions with the dengue NS2B/NS3 protease using the computational docking technique in the MOE and AutoDock (version 4.2) software. To this end, the researchers designed 26 linear pentapeptides based on previous studies. It was revealed that two linear pentapeptides (i.e., GKRRK and KRRRK) are the best potential inhibitors. Furthermore, based on the findings of the two independent docking programs, the peptide GKRRK was synthesized by solid-phase peptide synthesis and its structure was confirmed. The in-vitro protease inhibitor study was conducted for these two peptides to examine their activity against the dengue virus using a protin in as a control. It was found that the designed potential peptides possess interesting inhibition against the NS2B/NS3 protease. Additionally, the findings showed that the peptide GKRRK had the highest percentage of inhibition (71.11%) at 100 µM with the IC50 of 48.87 µM; therefore, this linear peptide could serve as a good inhibitor for the DENV.