Cell Penetrating Peptides and Cationic Antibacterial Peptides: two sides of the same coin [Computational Biology]

April 5th, 2014 by Rodriguez Plaza, J. G., Morales-Nava, R., Diener, C., Schreiber, G., Gonzalez, Z. D., Lara Ortiz, M. T., Ortega Blake, I., Pantoja, O., Volkmer, R., Klipp, E., Herrmann, A., Del Rio, G.

Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet, it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) since it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs.