Biochemical, pharmacological and genomic characterisation of Ts IV, an α‐toxin from the venom of the South American scorpion Tityus serrulatus

Abstract

The venom of the scorpion, Tityus serrulatus, was fractionated to investigate the chemical and pharmacological properties of its alpha-toxin content. Three alpha-toxins (Ts III, Ts IV and Ts V) were purified by conventional chromatography (gel filtration and ion-exchange chromatography), followed by immunoaffinity chromatography. Competition experiments using reference alpha- and beta-toxins suggested that these alpha-toxins were contaminated with around 0.01% of beta-toxin. The sequence of the first 30 amino acids of Ts IV was established. Using an oligonucleotide probe, a cDNA encoding its precursor was cloned from a venom gland cDNA library. The primary structure deduced from the cDNA nucleotide sequence provides possible explanations for the polymorphism of these three molecules.