Fig. 6

a Inhibition of cytopathic effect of B.t.LDC 501 parasporal protein on HCT 116 cells at aminopeptidase N (APN) inhibitor concentrations of 5 and 50 μM. No APN inhibition was observed in cells treated with activated proteins from BGSC-4Q2. b Cell viability assay showing approximately 85 % viable HCT 116 cells following treatment with APN inhibitor at various concentrations (5–50 μM) and B.t.LDC 501 protein; treated proteins from BGSC-4Q2 displayed only approximately 4 % of cell viability, independent of the APN inhibitor concentration. Each point represents mean ± SE (n = 3). Different lowercase letters above symbols indicate statistical significance at p ≤ 0.05 between the respective groups by the Tukey test