Net charge tuning modulates the antiplasmodial and anticancer properties of peptides derived from scorpion venom
Cibele Nicolaski Pedron, Adriana F. Silva, Marcelo D. T. Torres, Cyntia Silva Oliveira, Gislaine Patricia Andrade, Giselle Cerchiaro, Maria Aparecida da Silva Pinhal, César de la Fuente‐Núñez, Vani Xavier Oliveira
Abstract
VmCT1, a linear helical antimicrobial peptide isolated from the venom of the scorpion Vaejovis mexicanus , displays broad spectrum antimicrobial activity against bacteria, fungi, and protozoa. Analogs derived from this peptide containing single Arg‐substitutions have been shown to increase antimicrobial and antiparasitic activities against Trypanossoma cruzi . Here, we tested these analogs against malaria, an infectious disease caused by Plasmodium protozoa, and assessed their antitumoral properties. Specifically, we tested VmCT1 synthetic variants [Arg] 3 ‐VmCT1‐NH 2 , [Arg] 7 ‐VmCT1‐NH 2 , and [Arg] 11 ‐VmCT1‐NH 2 , against Plasmodium gallinaceum sporozoites and MCF‐7 mammary cancer cells. Our screen identified peptides [Arg] 3 ‐VmCT1‐NH 2 and [Arg] 7 ‐VmCT1‐NH 2 as potent antiplasmodial agents (IC 50 of 0.57 and 0.51 μmol L −1 , respectively), whereas [Arg] 11 ‐VmCT1‐NH 2 did not show activity against P. gallinaceum sporozoites. Interestingly, all peptides presented activity against MCF‐7 and displayed lower cytotoxicity toward healthy cells. We demonstrate that increasing the net positive charge of VmCT1, through arginine substitutions, modulates the biological properties of this peptide family yielding novel antiplasmodial and antitumoral molecules.