Enzymatic properties of venoms from Brazilian scorpions of Tityus genus and the neutralisation potential of therapeutical antivenoms

Abstract

Tityus scorpion stings are an important public health problem in Brazil, where the incidence of such stings exceeds the incidence of the health problems caused by other venomous animals, including snakes. In this study, we have analysed specific enzymatic activities of the venom from the Brazilian scorpions of Tityus genus, i.e., Tityus serrulatus, Tityus bahiensis and Tityus stigmurus. The data presented here revealed that Tityus spp. venoms exhibited significant hyaluronidase activity but no phospholipase activity. All the venom samples exhibited the ability to hydrolyse Abz-FLRRV-EDDnp and dynorphin 1-13 substrates. These activities were inhibited by 1,10-phenanthroline but not by PMSF, indicating the presence of metalloproteinases in the Tityus spp. venoms. The venom peptidase activity on Abz-FLRRV-EDDnp and on dynorphin 1-13 was partially inhibited by therapeutic Brazilian anti-scorpion and anti-arachnidic antivenoms. Dynorphin 1-13 (YGGFLRRIRPKLK) contains two scissile bonds between the residues Leu-Arg and Arg-Arg that are susceptible to cleavage by the Tityus venom metallopeptidase(s). Their cleavage releases leu-enkephalin, an important bioactive peptide. The detection of metalloproteinase(s) with specificity for both dynorphin 1-13 degradation and leu-enkephalin releasing can be important for the mechanistic understanding of hypotension and bradycardia induction in cases of scorpion stings, whereas hyaluronidases might contribute to the diffusion of the toxins present in these venoms. Furthermore, the limited inhibition of the toxic enzymatic activities by commercial antivenoms illustrates the necessity of improvements in current antivenom preparation.

Estudio bioquímico del veneno de Tityus kaderkai(Scorpiones: Buthidae) con notas sobre su distribución y hábitat en el Perú

“…Este resultado coincide con lo reportado para los venenos de Tityus serrulatus, T. bahiensis, T. stigmurus (Venancio et al 2013), Androctonus crassicauda, Mesobuthus eupeus (Khodadadi et al 2012) y Centruroides margaritatus (Escobar et al 2003b), en donde tampoco se ha detectado actividad de fosfolipasa. La fosfolipasa es una enzima que se encuentra ampliamente distribuida en diversos venenos de origen animal, incluído los escorpiones; sin embargo la ausencia de esta enzima parecería ser una característica común no solo de los venenos del género Tityus, sino una característica general de la familia Buthidae, pues todos los escorpiones arriba mencionados pertenecen a ésta familia.…”

Scorpionism and dangerous species of Brazil

“…All of them were treated with scorpion antivenom but died within 4 h, 8 h, and 30 h after of the accidents. T. stigmurus venom is the most toxic (DL 50 ¼ 0.773 mg/kg) when compared to T. serrulatus and T. bahiensis (Nishikawa et al 1994;Venancio et al 2013), although the proteomic profile places T. stigmurus and T. serrulatus as very close species and T. bahiensis the less related species in the Tityus genus (Nascimento et al 2006). One hundred distinct components have been described in T. stigmurus venom, showing molecular masses from 216.5 to 44,800 Da (Batista et al 2007).…”

“…The moderate envenomation or stage II is characterized with symptoms such as sweating, cramps, vomiting, hypotension, diarrhea, bradycardia, epigastric pain, pulmonary obstruction, and dyspnea (Chippaux and Goyffon 2008;Cupo et al 1994;Venancio et al 2013). Toxinology DOI 10.1007/978-94-007-6647-1_20-1 # Springer Science+Business Media Dordrecht 2014 The severe envenomation or stage III, which often occurs in children, may present several types of manifestations and is potentially lethal (Chippaux and Goyffon 2008;Cupo et al 1994;Venancio et al 2013).…”

Purificação e caracterização de peptidases presentes no veneno do escorpião <i>Tityus serrulatus</i>.

“…For instance, in snake venoms, serine peptidases can affect the coagulation cascade and kallikrein-kinin system, while metallopeptidases target components of blood coagulation and platelet aggregation, both resulting in an imbalance of the hemostatic system [10,11]. Although snake venom peptidases are the most studied, due to their abundance, proteolytic activity has recently been described in jellyfish [12], cone snail [13], wasp [14], spider [15], and scorpion [16] venoms.…”

“…venoms [6,9], although transcriptomic studies have identified other classes of enzymes as well [8,17]. Studies from our group have shown that Tsv proteases cleave mammal peptides in vitro, and that this activity is inhibited by high concentrations of commercially available antivenoms used in the treatment of envenomed patients in Brazil [16,18]. Moreover, endopeptidases, aminopeptidases, and carboxypeptidases that cleave endogenous peptides from the Tsv and inactivate human bioactive peptides have been detected [18,19].…”