Fig. 4From: SHTXTHHly, an extracellular secretion platform for the preparation of bioactive peptides and proteins in Escherichia coliBioactivities determination of the produced AMPs. Different concentrations (0–4000 nM) of cCeA and rCeA (A), or cLL37 and rLL37 (B), were incubated with E. coli 25,922 at 37 °C for 18 h, then the OD600 values were detected. Different concentrations (0–64 μM) of cA12 and rA12 (C) were incubated with U87 MG cells for 8 h, and the number of live cells was measured with the CCK-8 reagent. In other experiments, the concentration of A12 and the incubation time were set at 10 μM and 4 h, then the tumor lysis (D) and pro-apoptosis (E) effect were verified with a fluorescence microscope or an Annexin V-FITC/PI dyeBack to article page