Translocation and entry of label-free AMP, PGLa, without pore formation

    Hazrat et al have published the paper entitled with ” Translocation of the Nonlabeled Antimicrobial Peptide PGLa across Lipid Bilayers and its Entry into Vesicle Lumens without Pore Formation” (BBA-Biomembranes, 1863, 183680, 2021) [Abstract]. Fluorescent-probe-labeled antimicrobial peptides (AMPs) have been used to examine the interaction of AMPs with cells and lipid vesicles, but in some cases the effect of labeling changes their interaction. Recently we have developed a new method to detect the entry of cell-penetrating peptides (CPPs) into the lumen of single giant unilamellar vesicles (GUVs) (Biochemistry, 59, 1780-1790 (2020)). In this report, using this method, we examined the interaction of an AMP, PGLa, with single GUVs. We found that PGLa entered the GUV lumen without pore formation and the rate of its entry increased with PGLa concentration. The simultaneous measurement of the PGLa-induced area increase of a GUV and the entry of PGLa into GUV lumen indicates that immediately after the translocation of PGLa across the lipid bilayer PGLa enters the GUV lumen.