Mechanism and spectrum of inhibition of a 4′-cyano modified nucleotide analog against diverse RNA polymerases of prototypic respiratory RNA viruses

作者：Calvin J. Gordon, Simon Walker, Egor P. Tchesnokov, Dana Kocíncová, Jared Pitts, Dustin S. Siegel, Jason K. Perry, Joy Y. Feng, John P. Bilello, Matthias Götte · 发表于：Journal of Biological Chemistry · 年份：2024 · DOI：10.1016/j.jbc.2024.107514 · 被引用次数：13 · 研究领域：Viral gastroenteritis research and epidemiology、Respiratory viral infections research、Viral Infections and Immunology Research

The development of safe and effective broad-spectrum antivirals that target the replication machinery of respiratory viruses is of high priority in pandemic preparedness programs. Here, we studied the mechanism of action of a newly discovered nucleotide analog against diverse RNA-dependent RNA polymerases (RdRps) of prototypic respiratory viruses. GS-646939 is the active 5'-triphosphate metabolite of a 4'-cyano modified C-adenosine analog phosphoramidate prodrug GS-7682. Enzyme kinetics show that the RdRps of human rhinovirus type 16 (HRV-16) and enterovirus 71 incorporate GS-646939 with unprecedented selectivity; GS-646939 is incorporated 20-50-fold more efficiently than its natural ATP counterpart. The RdRp complex of respiratory syncytial virus and human metapneumovirus incorporate GS-646939 and ATP with similar efficiency. In contrast, influenza B RdRp shows a clear preference for ATP and human mitochondrial RNA polymerase does not show significant incorporation of GS-646939. Once incorporated into the nascent RNA strand, GS-646939 acts as a chain terminator although higher NTP concentrations can partially overcome inhibition for some polymerases. Modeling and biochemical data suggest that the 4'-modification inhibits RdRp translocation. Comparative studies with GS-443902, the active triphosphate form of the 1'-cyano modified prodrugs remdesivir and obeldesivir, reveal not only different mechanisms of inhibition, but also differences in the spectrum of inhibition of viral...