1,5-benzodiazepines, a novel class of hepatitis C virus polymerase nonnucleoside inhibitors.
The exogenous control of hepatitis C virus (HCV) replication can be mediated through the inhibition of the RNA-dependent RNA polymerase (RdRp) activity of NS5B. Small-molecule inhibitors of NS5B include nucleoside and nonnucleoside analogs. Here, we report the discovery of a novel class of HCV polymerase nonnucleoside inhibitors, 1,5-benzodiazepines (1,5-BZDs), identified by high-throughput screening of a library of small molecules. A fluorescence-quenching assay and X-ray crystallography revealed that 1,5-BZD 4a bound stereospecifically to NS5B next to the catalytic site. When introduced into replicons, mutations known to confer resistance against chemotypes that bind at this site were detrimental to inhibition by 1,5-BZD 7a. Using a panel of enzyme isolates that covered genotypes 1 to 6, we showed that compound 4a inhibited genotype 1 only. In mechanistic studies, 4a was found to inhibit the RdRp activity of NS5B noncompetitively with GTP and to inhibit the formation of the first phosphodiester bond during the polymerization cycle. The specificity for the HCV target was evaluated by profiling the 1,5-BZDs against other viral and human polymerases, as well as BZD receptors.
Tibotec BVBA, Generaal de Wittelaan L11B 3, 2800 Mechelen, Belgium. onyangui@its.jnj.com
Origène
O
Nyanguile
Frederik
F
Pauwels
Walter
W
Van den Broeck
Carlo W
CW
Boutton
Ludo
L
Quirynen
Tania
T
Ivens
Liesbet
L
van der Helm
Geneviève
G
Vandercruyssen
Wendy
W
Mostmans
Frédéric
F
Delouvroy
Pascale
P
Dehertogh
Maxwell D
MD
Cummings
Jean-Francois
JF
Bonfanti
Kenneth A
KA
Simmen
Pierre
P
Raboisson
D000998:Antiviral Agents / Q000378:metabolism / Q000494:pharmacology; D001569:Benzodiazepines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D017361:Viral Nonstructural Proteins; D001569:Benzodiazepines; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase