Fig 3. Inhibitor experiments.

Different protease inhibitors—phenanthroline, AEBSF, E-64 and pepstatin A—were tested for their ability to inhibit protease activity responsible for PFU-093 cleavage. Individual working concentrations are indicated in brackets. Pitcher fluid from N. mirabilis without any inhibitor was used as a control (from left, first bar). Additional controls were carried out with the particular solvents of the inhibitors (DMSO, MeOH, H₂O). Statistics was done using one-way ANOVA, All Pairwise Multiple Comparison Procedures (Student-Newman-Keuls Method), P<0.05; different letters indicate significant differences.