Cell-penetrating peptides are arginine-and lysine-rich cationic peptides that can readily
enter cells not only by themselves but also carrying other macromolecular cargos. In fact, we
have reported that polycationic polymer such as poly-l-lysine (PLL) and poly-l-arginine
(PLA) translocate through negatively charged phospholipid liposome membranes. In this
work, we made a comparative study of the interaction of PLL or PLA with lipid membranes
consisting of negatively charged phospholipids to understand the role of basic amino acid …