Figure 2.

Screening assays for ZIKV NS5 MTase inhibitors and identification of the hit compound theaflavin. (A) Inhibition of MTase by the positive control sinefungin. Two-fold dilutions (0.75-24 μM) of sinefungin were used. The MTase activity of the DMSO control was set as 100%. (B) Z’ factor of the luminescence-based assay. MTase was incubated with 20 μM positive control sinefungin or 1% DMSO for 1 h at room temperature. Then the luminescence intensity was measured and Z’ factor was calculated as described. (C) Structure of theaflavin. (D) WT-MTase and mutant MTases inhibition assays. Half maximal inhibition concentration (IC₅₀) values were calculated from dose-response curves in three independent experiments using GraphPad 6.0.