We identified Tf2, the first β-scorpion toxin from the venom of the Brazilian scorpion Tityus fasciolatus. Tf2 is identical to Tb2-II found in Tityus bahiensis. We found that Tf2 selectively activates human (h)Nav1.3, a neuronal voltage-gated sodium (Nav) subtype implicated in epilepsy and nociception. Tf2 shifts hNav1.3 activation voltage to more negative values, thereby opening the channel at resting membrane potentials. Seven other tested mammalian Nav channels (Nav1.1-1.2; Nav1.4-1.8) expressed in Xenopus oocytes are insensitive upon application of 1 μM Tf2. Therefore, the identification of Tf2 represents a unique addition to the repertoire of animal toxins that can be used to investigate Nav channel function.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4470819 | PMC |
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128578 | PLOS |
Biomedicines
June 2020
Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
Na1.3 is a subtype of the voltage-gated sodium channel family. It has been implicated in the pathogenesis of neuropathic pain, although the contribution of this channel to neuronal excitability is not well understood.
View Article and Find Full Text PDFToxins (Basel)
August 2018
Laboratório de Neurofarmacologia, Departamento de Ciências Biológicas, Universidade de Brasília, Brasília 70910-900, Distrito Federal, Brazil.
Scorpion venoms are a complex mixture of components. Among them the most important are peptides, which presents the capacity to interact and modulate several ion channel subtypes, including voltage-gated sodium channels (Na). Screening the activity of scorpion toxins on different subtypes of Na reveals the scope of modulatory activity and, in most cases, low channel selectivity.
View Article and Find Full Text PDFJ Venom Anim Toxins Incl Trop Dis
January 2018
1Laboratory of Pharmacology, Butantan Institute, Av. Dr. Vital Brasil, 1500, São Paulo, SP 05503-900 Brazil.
In Brazil, the scorpion species responsible for most severe incidents belong to the genus and, among this group, , , and are the most dangerous ones. Other species such as , , , , are also found in the country, but the incidence and severity of accidents caused by them are lower. The main effects caused by scorpion venoms - such as myocardial damage, cardiac arrhythmias, pulmonary edema and shock - are mainly due to the release of mediators from the autonomic nervous system.
View Article and Find Full Text PDFPLoS One
March 2016
Departamento de Ciências Fisiológicas, Laboratório de Toxinologia, Universidade de Brasília, Brasília, DF, Brazil.
We identified Tf2, the first β-scorpion toxin from the venom of the Brazilian scorpion Tityus fasciolatus. Tf2 is identical to Tb2-II found in Tityus bahiensis. We found that Tf2 selectively activates human (h)Nav1.
View Article and Find Full Text PDFToxicon
June 2015
Departamento de Bioquímica-Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, CEP: 31270-901 Belo Horizonte, MG, Brazil. Electronic address:
This communication describes the general characteristics of the venom from the Brazilian scorpion Tityus fasciolatus, which is an endemic species found in the central Brazil (States of Goiás and Minas Gerais), being responsible for sting accidents in this area. The soluble venom obtained from this scorpion is toxic to mice being the LD50 is 2.984 mg/kg (subcutaneally).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!