Proteomic characterization of Tityus championi venom and recombinant expression of its major neurotoxin.

BACKGROUND

Tityus championi is a species endemic to the southern Talamanca Mountain Range, along the border region between Costa Rica and Panama, and has been associated with severe clinical cases. Despite its medical relevance, the composition of its venom remains poorly studied. The present study aimed to characterize the proteomic composition of T. championi venom, identify its main toxin families, and recombinantly produce one of its most abundant and lethal toxins for potential use in antivenom development.

METHODS

Venom composition was analyzed by tandem mass spectrometry (MS/MS), enabling the identification of venom proteins. Subsequently, one of its primary lethal toxins (Tcham27) was identified and recombinantly expressed.

RESULTS

Proteomic analysis revealed that the most abundant family in the venom corresponded to metalloproteases, with 43 protein groups (17% of the total identifications), which are associated with processes such as hemorrhage, edema, inflammation, hypotension, and necrosis. CIIMET family toxins comprised 27 protein groups (11%). Among ion channel-acting toxins, 18 protein groups (7%) corresponded to sodium channel toxins and 14 (6%) to potassium channel toxins, homologous to components from geographically proximate species such as Tityus discrepans, Tityus cf. asthenes, and Tityus jaimei. Other relevant families included cysteine-rich secretory proteins (CRISPs; 6 proteins, 3%), serine proteases (5 proteins, 2%), and lectins (5 proteins, 2%). In addition, low-abundance components such as insulin-like growth factors, nucleotide pyrophosphatases, hyaluronidase, α-amylase, lipolysis-activated toxins, and chitinase were detected, contributing to the functional diversity of the venom.

CONCLUSIONS

Proteomic characterization of T. championi venom demonstrates that metalloproteases constitute a major protein family alongside neurotoxins. Recombinant production of its most abundant toxic peptide, which is identical to toxins in the venom of geographically proximate Tityus species, provides a key tool for developing specific antivenoms.