Characterization of the first two toxins isolated from the venom of the ancient scorpion Tityus (Archaeotityus) mattogrossensis (Borelli, 1901)

Abstract

Background: Almost all Tityus characterized toxins are from subgenera Atreus and Tityus , there are only a few data about toxins produced by Archaeotityus , an ancient group in Tityus genus. Methods: Tityus (Archaeotityus) mattogrossensis crude venom was fractionated by high performance liquid chromatography, the major fractions were tested in a frog sciatic nerve single sucrose-gap technique. Two fractions (Tm1 and Tm2) were isolated, partially sequenced by MALDI-TOF/MS and electrophysiological assayed on HEK293 Nav 1.3, HEK293 Nav 1.6, DUM and DRG cells. Results: The sucrose-gap technique showed neurotoxicity in four fractions. One fraction caused a delay of action potential repolarization and other three caused a reduction in amplitude. An electrophysiological assay showed that Tm1 is active on HEK293 Nav 1.3, HEK293 Nav 1.6, DUM and DRG cells, and Tm2 on HEK293 Nav 1.3 and DRG cells, but not in HEK293 Nav 1.6. In addition, Tm1 and Tm2 did promote a shift to more negative potentials strongly suggesting that both are α-NaScTx. Conclusion: Although Tityus (Archaeotityus) mattogrossensis is considered an ancient group in Tityus genus, the primary structure of Tm1 and Tm2 is more related to Tityus subgenus. The patch clamp electrophysiological tests suggest that Tm1 and Tm2 are NaScTx, and also promoted no shift to more negative potentials, strongly suggesting that both are α-NaScTx. This paper aimed to explore and characterize for the first time toxins from the ancient scorpion Tityus (Archaeotityus) mattogrossensis.

Venomics of the Scorpion Tityus ocelote (Scorpiones, Buthidae): Understanding Venom Evolution in the Subgenus Archaeotityus

“…In T. (Archaeotityus) clathratus, two toxin transcripts belonging to the β-toxin family of Na + channel modulating peptides, have been identi ed (Borges et al, 2012). Two other NaTxs have been isolated from the venom of T. (Archaeotityus) mattogrossensis, a species distributed in the Brazilian Cerrado ecosystem (de Oliveira et al, 2021). These four peptides share amino acid sequence homology with toxins from members of the subgenus T. (Tityus) (in particular, members of the T. bahiensis group sensu Lourenço, 2006Lourenço, , 2015 although they also show close identity with peptides reported in T. (Atreus) species (de Oliveira et al, 2021).…”

“…Two other NaTxs have been isolated from the venom of T. (Archaeotityus) mattogrossensis, a species distributed in the Brazilian Cerrado ecosystem (de Oliveira et al, 2021). These four peptides share amino acid sequence homology with toxins from members of the subgenus T. (Tityus) (in particular, members of the T. bahiensis group sensu Lourenço, 2006Lourenço, , 2015 although they also show close identity with peptides reported in T. (Atreus) species (de Oliveira et al, 2021). In both reports, no other components are mentioned, contributing to the assumption that Archaeotityus venoms are relatively simple in composition.…”