Specific targeting of hepatitis C virus NS3 RNA helicase. Discovery of the potent and selective competitive nucleotide-mimicking inhibitor QU663

Biochemistry. 2005 Jul 19;44(28):9637-44. doi: 10.1021/bi047437u.

Abstract

Hepatitis C virus (HCV) infection is an emerging global epidemic, and no effective cure is yet available. Interferon-alpha (INFalpha) and pegylated INFs, in combination or otherwise with ribavirin, have proven to be effective in no more than 50% of chronically infected patients. New and better therapeutic strategies are therefore needed. HCV nonstructural protein 3 (NS3) RNA helicase (h) is a promising target for developing new therapeutics. QU663 was discovered as a potent new selective inhibitor of the helicase reaction of HCV NS3 (K(i) = 0.75 microM), competing with the nucleic acid substrate without affecting ATPase function, even at high concentrations. QU663 is one of a new generation of small-molecule nucleotide-mimicking inhibitors which are potential anti-HCV agents. A thorough molecular modeling study was carried out to explain the molecular basis of NS3h inhibition by QU663. The resulting three-dimensional interaction model is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / chemistry*
  • Adenosine Triphosphate / metabolism
  • Antiviral Agents / chemical synthesis
  • Antiviral Agents / metabolism
  • Antiviral Agents / pharmacology
  • Binding Sites
  • Binding, Competitive
  • DNA, Viral / metabolism
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology
  • Hepacivirus / drug effects
  • Hepacivirus / enzymology*
  • Hydrazines / chemistry*
  • Hydrazines / pharmacology
  • Hydrolysis
  • Molecular Mimicry*
  • Pyrazines / chemistry*
  • Pyrazines / pharmacology
  • Quinolines / chemistry*
  • Quinolines / pharmacology
  • Quinoxalines / chemical synthesis*
  • Quinoxalines / metabolism
  • Quinoxalines / pharmacology
  • RNA Helicases / antagonists & inhibitors*
  • RNA Helicases / metabolism
  • Substrate Specificity / drug effects
  • Viral Nonstructural Proteins / antagonists & inhibitors*
  • Viral Nonstructural Proteins / metabolism

Substances

  • Antiviral Agents
  • DNA, Viral
  • Enzyme Inhibitors
  • Hydrazines
  • NS3 protein, hepatitis C virus
  • Pyrazines
  • QU663 compound
  • Quinolines
  • Quinoxalines
  • Viral Nonstructural Proteins
  • Adenosine Triphosphate
  • RNA Helicases

Associated data

  • PDB/1A1V
  • PDB/1CU1