Purification, amino-acid sequence and partial characterization of two toxins with anti-insect activity from the venom of the South American scorpion Tityus bahiensis (Buthidae).

• Autor(a) principal: Pimenta, Adriano Monteiro de Castro
• Data de Publicação: 2001
• Outros Autores: Eauclaire, Marie France Martin, Rochat, Hervé, Figueiredo, Suely Gomes de, Kalapothakis, Evanguedes, Afonso, Luís Carlos Crocco, Lima, Maria Elena de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFOP
• Texto Completo: http://www.repositorio.ufop.br/handle/123456789/4617; https://doi.org/10.1016/S0041-0101(00)00240-3
• topic: Tityus bahiensis; Toxin; Anti-insect activity; Three-dimensional models

We report here the isolation by a two-step chromatographic procedure of two new toxins from the South American scorpion Tityus bahiensis. Their amino-acid sequences and some of their biological features were established. The two toxins have different biological properties. Toxin TbIT-I had almost no activity or pharmacological effects in vertebrate tissues whereas it was lethal to house ¯ies (LD50 80.0 ng/house ¯y). In contrast, Tb2-II was active against both mammals (intracerebroventricular injection of 100 ng/mouse was lethal) and insects (LD50 40.0 ng/house ¯y). The amino-acid sequences of these toxins were established and found to be similar (60±95%) to previously described b-toxins from the Tityus genus. Based on the available comparative information, this study attempts identify possible structure±function relationships that may be responsible for the differences in bioactivity displayed by these toxins.