FIGURE 1.

Eriodictyol acts as a reversible inhibitor of SrtA. (A) Chemical structure of eriodictyol. (B) Eriodictyol inhibited the cleavage of the Abz-LPATG-Dap (Dnp)-NH₂ substrate by SrtA in a dose-dependent manner. Each reaction condition was assayed in triplicate, and the data are presented as the mean ± SEM. (C) SrtA was treated with or without 10 × IC₅₀ of eriodictyol and then diluted; the SrtA activity was subsequently determined by FRET assay. Untreated SrtA (mock) was assumed as 100% activity. (D) Growth curves of S. aureus USA 300 and the ΔsrtA mutant strains with or without eriodictyol (128 μg/mL). (E) Percentage of viability of Vero cells was measured by the CCK-8 assay after 24 h of incubation with eriodictyol (0–512 μg/mL).