The GA-Hecate Peptide inhibits the ZIKV Replicative Cycle in Different Steps and can Inhibit the Flavivirus NS2B-NS3 Protease after Cell Infection

Protein Pept Lett. 2024;31(7):532-543. doi: 10.2174/0109298665308871240703090408.

Abstract

Background: Peptide drugs are advantageous because they are subject to rational design and exhibit highly diverse structures and broad biological activities. The NS2B-NS3 protein is a particularly promising flavivirus therapeutic target, with extensive research on the development of inhibitors as therapeutic candidates, and was used as a model in this work to determine the mechanism by which GA-Hecate inhibits ZIKV replication.

Objective: The present study aimed to evaluate the potential of GA-Hecate, a new antiviral developed by our group, against the Brazilian Zika virus and to evaluate the mechanism of action of this compound on the flavivirus NS2B-NS3 protein.

Methods: Solid-phase peptide Synthesis, High-Performance Liquid Chromatography, and Mass Spectrometry were used to obtain, purify, and characterize the synthesized compound. Real-time and enzymatic assays were used to determine the antiviral potential of GA-Hecate against ZIKV.

Results: The RT-qPCR results showed that GA-Hecate decreased the number of ZIKV RNA copies in the virucidal, pre-treatment, and post-entry assays, with 5- to 6-fold fewer RNA copies at the higher nontoxic concentration in Vero cells (HNTC: 10 μM) than in the control cells. Enzymatic and kinetic assays indicated that GA-Hecate acts as a competitive ZIKV NS2B-NS3 protease inhibitor with an IC50 of 32 nM and has activity against the yellow fever virus protease.

Conclusion: The results highlight the antiviral potential of the GA-Hecate bioconjugate and open the door for the development of new antivirals.

Keywords: NS2B-NS3.; Zika virus; bioconjugate; flavivirus; peptides; protease.

MeSH terms

  • Animals
  • Antiviral Agents* / chemistry
  • Antiviral Agents* / pharmacology
  • Chlorocebus aethiops
  • DEAD-box RNA Helicases
  • Humans
  • Nucleoside-Triphosphatase
  • Peptides / chemistry
  • Peptides / pharmacology
  • Protease Inhibitors / chemistry
  • Protease Inhibitors / pharmacology
  • RNA Helicases / antagonists & inhibitors
  • RNA Helicases / metabolism
  • Serine Endopeptidases / metabolism
  • Vero Cells
  • Viral Nonstructural Proteins* / antagonists & inhibitors
  • Viral Nonstructural Proteins* / metabolism
  • Viral Proteases
  • Virus Replication* / drug effects
  • Zika Virus Infection / drug therapy
  • Zika Virus Infection / virology
  • Zika Virus* / drug effects

Substances

  • Antiviral Agents
  • Viral Nonstructural Proteins
  • NS2B protein, flavivirus
  • Serine Endopeptidases
  • Peptides
  • RNA Helicases
  • NS3 protein, flavivirus
  • NS3 protein, Zika virus
  • Protease Inhibitors
  • Viral Proteases
  • Nucleoside-Triphosphatase
  • DEAD-box RNA Helicases