Self-association of a highly charged arginine-rich cell-penetrating peptide
Résumé
Significance Arginine-rich cell-penetrating peptides are promising candidates for intracellular drug delivery. These cationic peptides spontaneously traverse biological membranes via a direct mode of entry which is not yet fully understood. In this study, we report the complex solution behavior of the cell-penetrating peptide deca-arginine. Despite its large net positive charge, deca-arginine self-associates at low-to-intermediate ionic strengths, owing to an interaction mode which is present in the structure of a significant number of proteins. Self-association may thus enhance the bioavailability of deca-arginine. Our findings provide the key to the understanding of the self-association mechanism in deca-arginine with implications for the potential biological roles of this unusual binding motif.