Effect of a hepatitis B virus inhibitor, NZ-4, on capsid formation

Antiviral Res. 2016 Jan:125:25-33. doi: 10.1016/j.antiviral.2015.11.004. Epub 2015 Nov 30.

Abstract

During the hepatitis B virus (HBV) life cycle, nucleocapsid assembly is essential for HBV replication. Both RNA reverse transcription and DNA replication occur within the HBV nucleocapsid. HBV nucleocapsid is consisted of core protein (HBcAg), whose carboxy-terminal domain (CTD) contains an Arg-rich domain (ARD). The ARD of HBcAg does contribute to the encapsidation of pregenomic RNA (pgRNA). Previously, we reported a small-molecule, NZ-4, which dramatically reduced the HBV DNA level in an in vitro cell setting. Here, we explore the possible mechanisms by which NZ-4 inhibits HBV function. As an HBV inhibitor, NZ-4 leads to the formation of genome-free capsids, including a new population of capsid that runs faster on agarose gels. NZ-4's activity was dependent on the presence of the ARD I, containing at least one positively charged amino acid. NZ-4 might provide a new option for further development of HBV therapeutics for the treatment of chronic hepatitis B.

Keywords: Anti-hepatitis B virus compound; Arg-rich domain I; Capsid formation; Faster-migrating capsid; pgRNA packaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Capsid / drug effects*
  • Capsid / metabolism*
  • Cell Line, Tumor
  • DNA, Viral / genetics
  • DNA, Viral / metabolism
  • Endoribonucleases / genetics
  • Endoribonucleases / metabolism
  • Genome, Viral
  • Hep G2 Cells
  • Hepatitis B Core Antigens / genetics
  • Hepatitis B virus / drug effects*
  • Hepatitis B virus / genetics
  • Hepatitis B virus / metabolism
  • Humans
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism
  • RNA, Viral / genetics
  • RNA, Viral / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Thiazoles / pharmacology*
  • Virus Replication / drug effects

Substances

  • DNA, Viral
  • Hepatitis B Core Antigens
  • RNA, Viral
  • RNA-Binding Proteins
  • Thiazoles
  • isothiafludine
  • Endoribonucleases
  • Phosphoprotein Phosphatases
  • PPP1R8 protein, human