FIGURE 4.

Cationic amino acids at the N-terminal α-helix are not responsible for binding but play a role in killing of bacteria. (A) Binding of Ang4 and its mutants to the bacterial cell membrane, as measured by ELISA at 450 nm. PBS was used as a control. (B) Salmonella growth curve after 2 h of incubation with or without Ang4 or its mutants. (C) Bacterial killing assay after 2 h of incubation with Ang4 or its mutants, as measured by colony count. (D) NPN uptake assay to identify bacterial outer membrane rupture following addition of Ang4 or its mutants. (E,F) PI staining to assess changes in bacterial cell membrane integrity after 2 h of treatment with Ang4 or its mutants. All data are presented as mean ± SD from three independent experiments. P-values were determined by one-way ANOVA with Tukey’s multiple comparisons test; ns > 0.05, ^**P < 0.01, ^***P < 0.001 vs. WT Ang4.