Identification of AP80978, a novel small-molecule inhibitor of hepatitis C virus replication that targets NS4B.
A small-molecule inhibitor of hepatitis C virus (HCV) designated AP89652 was identified by screening a compound library with an HCV genotype 1b subgenomic replicon assay. AP89652 contains two chiral centers, and testing of two syn enantiomers revealed that activity in the replicon assay resided with only one, AP80978, whose 50% effective concentration (EC50) (the concentration at which a 50% reduction in Renilla luciferase levels was observed relative to an untreated control) was 630 nM. AP80978 was inhibitory against HCV genotypes 1a and 1b but not genotype 2a. In a replicon clearance assay, the potency and clearance rate of AP80978 were similar to those of telaprevir (VX950) and cyclosporine (CsA). AP80978 was nontoxic when tested against a panel of human cell lines, and inhibitory activity was HCV specific in that there was limited activity against negative-strand viruses, an alphavirus, and flaviviruses. By selection of resistant replicons and assessment of activity in genotype 1b/2a intergenotypic replicons, the viral protein target of this compound was identified as NS4B. NS4B F98V/L substitutions were confirmed by site-directed mutagenesis as AP80978 resistance-associated mutations. When tested against HCV produced in cell culture, the compound was significantly more potent than other HCV inhibitors, including VX950, CsA, and 2'-C-methyladenosine (2'C-meA). In addition, AP80977, the enantiomer that was inactive in the replicon assay, had activity against the virus, although it was lower than the activity of AP80978. These results suggest that AP80978 has the potential to be optimized into an effective antiviral drug and is a useful tool to further study the role of NS4B in HCV replication.
Apath, LLC, Brooklyn, New York, USA.
Jodi
J
Dufner-Beattie
Apath, LLC, Brooklyn, New York, USA.
Andrew
A
O'Guin
Apath, LLC, Brooklyn, New York, USA.
Stephanie
S
O'Guin
Apath, LLC, Brooklyn, New York, USA.
Aaron
A
Briley
Apath, LLC, Brooklyn, New York, USA.
Bin
B
Wang
Apath, LLC, Brooklyn, New York, USA.
Jennifer
J
Balsarotti
Apath, LLC, Brooklyn, New York, USA.
Robert
R
Roth
Apath, LLC, Brooklyn, New York, USA.
Gale
G
Starkey
Apath, LLC, Brooklyn, New York, USA.
Urszula
U
Slomczynska
Apath, LLC, Brooklyn, New York, USA.
Amine
A
Noueiry
Apath, LLC, Brooklyn, New York, USA.
Paul D
PD
Olivo
Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York, USA ricec@mail.rockefeller.edu.
Charles M
CM
Rice
D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology*; D001681:Biological Assay; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology; D005663:Furans / Q000494:pharmacology*; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics; D006526:Hepatitis C / Q000188:drug therapy* / Q000821:virology; D057166:High-Throughput Screening Assays; D006801:Humans; D049410:Luciferases, Renilla; D016297:Mutagenesis, Site-Directed; D009842:Oligopeptides / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D012093:Replicon / Q000187:drug effects; D013876:Thiophenes / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors*; D014779:Virus Replication / Q000187:drug effects
C569537:2'-C-methyladenosine; C000617453:AP80978; D000998:Antiviral Agents; D005663:Furans; C080107:NS4B protein, flavivirus; D009842:Oligopeptides; D011725:Pyridines; D013876:Thiophenes; D017361:Viral Nonstructural Proteins; C486464:telaprevir; D016572:Cyclosporine; D049410:Luciferases, Renilla; D000241:Adenosine