Permeabilization of mitochondria and red blood cells by polycationic peptides BTM-P1 and retro-BTM-P1

► The peptide BTM-P1, derived from Cry11Bb protoxins, was more active than retro-BTM-1. ► Biphasic “contraction-swelling” response of red blood cells to the peptide BTM-P1. ► The cell suicide mechanism increases the efficacy of polycationic peptides. ► The dipole moment of BTM-P1 as a possible factor of its high permeabilizing activity.