Figure 6.

The exonuclease activity of nsp14–nsp10 is inhibited by the presence of drugs and drug-like compounds. (A) Increasing concentrations (as indicated, in μM) of drug and drug-like compounds were incubated with 100 nM nsp14–nsp10 (room temperature, 10 min), before initiation of nuclease reaction by the addition of ssRNA (37°C, 45 min). Products were analysed by 20% denaturing PAGE. A decrease in the generation of nucleolytic reaction products and a concomitant increase in undigested substrate indicates inhibition of nuclease activity. – indicates no enzyme. Gels are representative of at least three biological repeats. (B) IC₅₀ values as calculated by quantification of gel digestion products (100 nM nsp14–nsp10) and dose-response curves were determined by nonlinear regression. The mean ± s.e.m. were calculated from ≥3 biological repeats. Precise IC₅₀ values should be regarded as preliminary due to the nature of the assay.