Potent cationic inhibitors of West Nile virus NS2B/NS3 protease with serum stability, cell permeability and antiviral activity

J Med Chem. 2008 Sep 25;51(18):5714-21. doi: 10.1021/jm800503y. Epub 2008 Aug 26.

Abstract

West Nile virus (WNV) has spread rapidly around the globe, efficiently crossing species from migrating birds into humans and other mammals. The viral protease NS2B-NS3 is important for WNV replication and recognizes dibasic substrate sequences common to other flaviviral proteases but different from most mammalian proteases. Potent inhibitors of WNV protease with antiviral activity have been elusive to date. We report the smallest and most potent inhibitors known for this enzyme, cationic tripeptides with nonpeptidic caps at the N-terminus and aldehyde at the C-terminus. One of these, compound 3 ( Ki = 9 nM) is stable in serum (>90% intact after 3 h, 37 degrees C), cell permeable, and shows antiviral activity (IC 50 1.6 microM) without cytotoxicity (IC 50 >400 microM), thereby validating the approach of inhibiting WNV protease to suppress WNV replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiviral Agents / blood
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology*
  • Cations
  • Models, Molecular
  • Protease Inhibitors / blood
  • Protease Inhibitors / chemistry
  • Protease Inhibitors / pharmacology*
  • RNA Helicases / antagonists & inhibitors
  • RNA Helicases / chemistry
  • RNA Helicases / metabolism
  • Serine Endopeptidases / chemistry
  • Serine Endopeptidases / metabolism
  • Substrate Specificity
  • Viral Nonstructural Proteins / antagonists & inhibitors*
  • Viral Nonstructural Proteins / chemistry
  • Viral Nonstructural Proteins / metabolism

Substances

  • Antiviral Agents
  • Cations
  • NS2B protein, flavivirus
  • NS3 protein, flavivirus
  • Protease Inhibitors
  • Viral Nonstructural Proteins
  • Serine Endopeptidases
  • RNA Helicases