Protegrin-1 Inhibits Dengue NS2B-NS3 Serine Protease and Viral Replication in MK2 Cells

Abstract EN

Dengue diseases have an economic as well as social burden worldwide.

In this study, the antiviral activity of protegrin-1 (PG-1, RGGRLCYCRRRFCVCVGR) peptide towards dengue NS2B-NS3pro and viral replication in Rhesus monkey kidney (MK2) cells was investigated.

The peptide PG-1 was synthesized by solid-phase peptide synthesis, and disulphide bonds formation followed by peptide purification was confirmed by LC-MS and RPHPLC.

Dengue NS2B-NS3pro was produced as a single-chain recombinant protein in E.

coli.

The NS2B-NS3pro assay was carried out by measuring the florescence emission of catalyzed substrate.

Real-time PCR was used to evaluate the inhibition potential of PG-1 towards dengue serotype-2 (DENV-2) replication in MK2 cells.

The results showed that PG-1 inhibited dengue NS2B-NS3pro at IC50 of 11.7 μM.

The graded concentrations of PG-1 at nontoxic range were able to reduce viral replication significantly (P<0.001) at 24, 48, and 72 hrs after viral infection.

However, the percentage of inhibition was significantly (P<0.01) higher at 24 hrs compared to 48 and 72 hrs.

These data show promising therapeutic potential of PG-1 against dengue infection, hence it warrants further analysis and improvement of the peptide features as a prospective starting point for consideration in designing attractive dengue virus inhibitors.