FIGURE 3.

Antimicrobial activity of Ang4 against Salmonella typhimurium LT2 is independent of RNase activity. (A) RNase activity of Ang4 and H12A determined by measuring the absorbance of perchloric acid soluble RNA fragments after 2 h incubation of assay mixtures at 37°C. (B) Growth profile of bacteria incubated with or without Ang4 or H12A at 37°C for 2 h. (C) Killing percentage of bacteria that were treated with PBS alone, Ang4, or H12A for 2 h before plating on LB agar plates. (D) Binding of Ang4 and H12A to bacteria was evaluated by ELISA. (E) The permeability of the bacterial outer membrane induced by Ang4 or H12A was assessed by measuring the fluorescence of NPN. (F,G) Flow cytometry to detect the inner membrane permeability of bacteria exposed to Ang4 or H12A using PI. All data are shown as mean ± SD from three independent experiments. P-values were determined by two-tailed unpaired t-test or one-way ANOVA with Tukey’s multiple comparisons test; ns > 0.05, ^***P < 0.001 vs. WT Ang4.