Structural characterization of a novel peptide with antimicrobial activity from the venom gland of the scorpion Tityus stigmurus: Stigmurin

Abstract

A new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5μM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug.

Keywords: Amphipathic peptide; Antimicrobial peptide (AMP); Circular dichroism (CD); Non-disulfide-bridged peptide (NDBP); Scorpion venom; Tityus stigmurus.