Inhibition of Chikungunya virus by an adenosine analog targeting the SAM-dependent nsP1 methyltransferase.
FEBS Lett 2019;
594:678-694. [PMID:
31623018 PMCID:
PMC7164056 DOI:
10.1002/1873-3468.13642]
[Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/23/2019] [Accepted: 10/02/2019] [Indexed: 01/02/2023]
Abstract
Alphaviruses, including Chikungunya (CHIKV) and Venezuelan equine encephalitis virus (VEEV), are among the leading causes of recurrent epidemics all over the world. Alphaviral nonstructural protein 1 (nsP1) orchestrates the capping of nascent viral RNA via its S-adenosyl methionine-dependent N-7-methyltransferase (MTase) and guanylyltransferase activities. Here, we developed and validated a novel capillary electrophoresis (CE)-based assay for measuring the MTase activity of purified VEEV and CHIKV nsP1. We employed the assay to assess the MTase inhibition efficiency of a few adenosine analogs and identified 5-iodotubercidin (5-IT) as an inhibitor of nsP1. The antiviral potency of 5-IT was evaluated in vitro using a combination of cell-based assays, which suggest that 5-IT is efficacious against CHIKV in cell culture (EC50 : 0.409 µm).
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