Subtype Specificity of β-Toxin Tf1a from Tityus fasciolatus in Voltage Gated Sodium Channels
Daniel Oliveira da Mata,
Diogo Vieira Tibery,
Leandro Ambrósio Campos,
Thalita Soares Camargos,
Steve Peigneur,
Jan Tytgat,
Elisabeth Ferroni Schwartz
Affiliations
Daniel Oliveira da Mata
Laboratório de Neurofarmacologia, Departamento de Ciências Biológicas, Universidade de Brasília, Brasília 70910-900, Distrito Federal, Brazil
Diogo Vieira Tibery
Laboratório de Neurofarmacologia, Departamento de Ciências Biológicas, Universidade de Brasília, Brasília 70910-900, Distrito Federal, Brazil
Leandro Ambrósio Campos
Laboratório de Neurofarmacologia, Departamento de Ciências Biológicas, Universidade de Brasília, Brasília 70910-900, Distrito Federal, Brazil
Thalita Soares Camargos
Departamento de Ciências da Saúde, Centro Universitário UDF, Brasília 70390-045, Distrito Federal, Brazil
Steve Peigneur
Toxicology and Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven (KU Leuven), P.O. Box 922, Herestraat 49, 3000 Leuven, Belgium
Jan Tytgat
Toxicology and Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven (KU Leuven), P.O. Box 922, Herestraat 49, 3000 Leuven, Belgium
Elisabeth Ferroni Schwartz
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 (NaV). Screening the activity of scorpion toxins on different subtypes of NaV reveals the scope of modulatory activity and, in most cases, low channel selectivity. Until now there are approximately 60 scorpion toxins experimentally assayed on NaV channels. However, the molecular bases of interaction between scorpion toxins and NaV channels are not fully elucidated. The activity description of new scorpion toxins is crucial to enhance the predictive strength of the structural–function correlations of these NaV modulatory molecules. In the present work a new scorpion toxin (Tf1a) was purified from Tityus fasciolatus venom by RP-HPLC, and characterized using electrophysiological experiments on different types of voltage-gated sodium channels. Tf1a was able to modify the normal function of NaV tested, showing to be a typical β-NaScTx. Tf1a also demonstrated an unusual capability to alter the kinetics of NaV1.5.
