Table 1.
Activity of PR-39 derived peptides against B. globigii and E. coli.
Figure 1.
PR-39 derived peptides are active against Bacillus globigii.
Peptides were incubated for 3×106 CFU/ml B. globigii in phosphate buffer (10 mM, pH 7; 1/100 TSB). Bacteria were serially diluted, plated on TSA plates and counted after 24 h. Shown are mean ± SEM of n≥3. For clarity, the data of 8 peptides is divided over 2 figures.
Figure 2.
PR-39 derived peptides cause release of bacterial ATP.
Bacteria were incubated for 5 µM peptides. ATP in supernatant and cell pellet were determined using a luciferase bioluminescence kit. A: E. coli, B: B. globigii. Shown are mean ± SEM of at least three independent experiments in triplicate. *: p<0.05 compared to the no-peptide control.
Figure 3.
PR-39 is most active in disrupting the membrane potential of B. globigii.
The membrane potential sensitive dye DiSC3(5) was incubated with bacteria until a stable baseline was formed. Fluorescence increase upon addition of peptide was measured at Excitation/Emmission 640/670 nm. Shown are representative curves of:PR-39: 2.5 µM, PR-39(1–26): 2.5 µM; PR-39(1–22): 2.5 µM; PR-39(1–18): 2.5 µM; PR-39(1–15): 5 µM; PR-39(16–39): 10 µM; PR-39(20–39): 20 µM; PR-39 (24–39): 10 µM.
Figure 4.
PR-39 derived peptides have low cytotoxicity.
Porcine macrophages (3D4/31 cells) were incubated for 24 h with 0–40 µM peptide. Metabolic activity was determined using WST-1 reagent. For clarity, the metabolic activity compared to the control (no peptide, 100%) is shown only for 5 (grey) and 40 µM (black) peptide. Shown are mean ± SEM of at least three independent experiments. For full data set please see Table S2.
Figure 5.
PR-39, but not shorter PR-39 derived peptides induce IL-8 production.
Porcine macrophages (3D4/31 cells) were incubated with 20 µM peptides for 4 (white bars) or 24 h (black bars). A) IL-8 and B) TNF-α production in the cell supernatant was determined using ELISA. Shown are mean ± SEM of at least three independent experiments. *: p<0.05 compared to the no peptide control.