tetano
Editor, Senior Moderator
Antimicrob Agents Chemother. 2013 Aug 5. [Epub ahead of print]
Mechanism of action of T-705 ribosyl triphosphate against influenza virus RNA polymerase.
Sangawa H, Komeno T, Nishikawa H, Yoshida A, Takahashi K, Nomura N, Furuta Y.
Source
Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama, Japan.
Abstract
T-705 (Favipiravir, 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) selectively and strongly inhibits replication of the influenza virus in vitro and in vivo. T-705 has been shown to be converted to T-705-4-ribofuranosyl-5-triphosphate (T-705RTP) by intracellular enzymes and then functions as a nucleotide analog to selectively inhibit RNA-dependent RNA polymerase (RdRp) of the influenza virus. To elucidate these inhibitory mechanisms, we herein analyzed the enzyme kinetics of inhibition using Lineweaver-Burk plots of four natural nucleoside triphosphates and conducted polyacrylamide gel electrophoresis of the primer extension products initiated from 32P-radiolabeled 5' Cap1 RNA. Enzyme kinetic analysis demonstrated that T-705RTP inhibited the incorporation of ATP and GTP in a competitive manner, which suggests that T-705RTP is recognized as a purine nucleotide by influenza virus RdRp and inhibited the incorporation of UTP and CTP in non-competitive and mixed-type manners, respectively. Primer extension analysis demonstrated that a single molecule of T-705RTP was incorporated into the nascent RNA strand of the influenza virus and inhibited the subsequent incorporation of nucleotides. These results suggest that a single molecule of T-705RTP is incorporated into the nascent RNA strand as a purine nucleotide analog and inhibits strand extension, even though the natural ribose of T-705RTP has a 3' -OH group, which is essential for forming a covalent bond with the phosphate group.
PMID:
23917318
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23917318
Mechanism of action of T-705 ribosyl triphosphate against influenza virus RNA polymerase.
Sangawa H, Komeno T, Nishikawa H, Yoshida A, Takahashi K, Nomura N, Furuta Y.
Source
Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama, Japan.
Abstract
T-705 (Favipiravir, 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) selectively and strongly inhibits replication of the influenza virus in vitro and in vivo. T-705 has been shown to be converted to T-705-4-ribofuranosyl-5-triphosphate (T-705RTP) by intracellular enzymes and then functions as a nucleotide analog to selectively inhibit RNA-dependent RNA polymerase (RdRp) of the influenza virus. To elucidate these inhibitory mechanisms, we herein analyzed the enzyme kinetics of inhibition using Lineweaver-Burk plots of four natural nucleoside triphosphates and conducted polyacrylamide gel electrophoresis of the primer extension products initiated from 32P-radiolabeled 5' Cap1 RNA. Enzyme kinetic analysis demonstrated that T-705RTP inhibited the incorporation of ATP and GTP in a competitive manner, which suggests that T-705RTP is recognized as a purine nucleotide by influenza virus RdRp and inhibited the incorporation of UTP and CTP in non-competitive and mixed-type manners, respectively. Primer extension analysis demonstrated that a single molecule of T-705RTP was incorporated into the nascent RNA strand of the influenza virus and inhibited the subsequent incorporation of nucleotides. These results suggest that a single molecule of T-705RTP is incorporated into the nascent RNA strand as a purine nucleotide analog and inhibits strand extension, even though the natural ribose of T-705RTP has a 3' -OH group, which is essential for forming a covalent bond with the phosphate group.
PMID:
23917318
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23917318