title: Dinucleotide analogues as novel inhibitors of RNA-dependent RNA polymerase of hepatitis C Virus.
abstract: Replication of hepatitis C virus (HCV) RNA is catalyzed by the virally encoded RNA-dependent RNA polymerase NS5B. It is believed that the viral polymerase utilizes a de novo or primer-independent mechanism for initiation of RNA synthesis. Our previous work has shown that dinucleotides were efficient initiation molecules for NS5B in vitro (W. Zhong, E. Ferrari, C. A. Lesburg, D. Maag, S. K. Ghosh, C. E. Cameron, J. Y. Lau, and Z. Hong, J. Virol. 74:9134-9143, 2000). In this study, we further demonstrated that dinucleotide analogues could serve as inhibitors of de novo initiation of RNA synthesis directed by HCV NS5B. Both mononucleotide- and dinucleotide-initiated RNA syntheses were affected by dinucleotide analogues. The presence of the 5'-phosphate group in the dinucleotide compounds was required for efficient inhibition of de novo initiation. Optimal inhibitory activity also appeared to be dependent on the base-pairing potential between the compounds and the template terminal bases. Because the initiation process is a rate-limiting step in viral RNA replication, inhibitors that interfere with the initiation process will have advantages in suppressing virus replication. The use of dinucleotide analogues as inhibitor molecules to target viral replication initiation represents a novel approach to antiviral interference.
authors.affiliation: Drug Discovery, Ribapharm, Inc., Costa Mesa, California 92626, USA. wzhong@ribapharm.com
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhong
authors.forename: Haoyun
authors.initials: H
authors.lastname: An
authors.forename: Dinesh
authors.initials: D
authors.lastname: Barawkar
authors.forename: Zhi
authors.initials: Z
authors.lastname: Hong
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors*; D015195:Drug Design; D016174:Hepacivirus / Q000187:drug effects / Q000201:enzymology*; D009711:Nucleotides / Q000138:chemical synthesis / Q000494:pharmacology*; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D013329:Structure-Activity Relationship; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D009711:Nucleotides; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases