Antimyotoxic Activity of Synthetic Peptides Derived from Bothrops atrox Snake Gamma Phospholipase A2 Inhibitor Selected by Virtual Screening

Background: Several studies have aimed to identify molecules that inhibit the toxic actions of snake venom phospholipases A(2) (PLA(2)s). Studies carried out with PLA(2) inhibitors (PLIs) have been shown to be efficient in this assignment. Objective: This work aimed to analyze the interaction of peptides derived from Bothrops atrox PLI gamma (atPLI gamma) with a PLA(2) and to evaluate the ability of these peptides to reduce phospholipase and myotoxic activities. Methods: Peptides were subjected to molecular docking with a homologous Lys49 PLA(2) from B. atrox venom modeled by homology. Phospholipase activity neutralization assay was performed with BthTX-II and different ratios of the peptides. A catalytically active and an inactive PLA(2) were purified from the B. atrox venom and used together in the in vitro myotoxic activity neutralization experiments with the peptides. Results: The peptides interacted with amino acids near the PLA(2) hydrophobic channel and the loop that would be bound to calcium in Asp49 PLA(2). They were able to reduce phospholipase activity and peptides DFCHNV and ATHEE reached the highest reduction levels, being these two peptides the best that also interacted in the in silico experiments. The peptides reduced the myotubes cell damage with a highlight for the DFCHNV peptide, which reduced by about 65%. It has been suggested that myotoxic activity reduction is related to the sites occupied in the PLA(2) structure, which could corroborate the results observed in molecular docking. Conclusion: This study should contribute to the investigation of the potential of PLIs to inhibit the toxic effects of PLA(2)s.