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.

• Authors: Emerson J Venancio, Fernanda C V Portaro, Alexandre K Kuniyoshi, Daniela Cajado Carvalho, Giselle Pidde-Queiroz, Denise V Tambourgi
• Journal: Toxicon : official journal of the International Society on Toxinology (Toxicon) Vol. 69 Pg. 180-90 (Jul 2013) ISSN: 1879-3150 [Electronic] England
• PMID: 23506858 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical References

• Antivenins
• Dipeptides
• Scorpion Venoms
• arginylarginine
• leucylarginine
• Phospholipases
• Hyaluronoglucosaminidase
• Metalloproteases

Topics

• Animals
• Antivenins (pharmacology)
• Brazil
• Chromatography, High Pressure Liquid
• Dipeptides (metabolism)
• Enzyme-Linked Immunosorbent Assay
• Hyaluronoglucosaminidase (metabolism)
• Incidence
• Metalloproteases (metabolism)
• Neutralization Tests (methods)
• Phospholipases (metabolism)
• Scorpion Stings (drug therapy, epidemiology)
• Scorpion Venoms (toxicity)
• Scorpions (classification)
• Species Specificity