BIOTECHNOLOGICAL APPLICATIONS OF INSECTICIDAL TOXINS FROM THE VENOM OF THE BROWN SPIDER Loxosceles intermedia

CASTRO, C.S.(1), SILVESTRE, F.G.(2), RIBEIRO, B.M.(2), MANGILI, O.C.(3), CHÁVEZ-OLÓRTEGUI, C.(4), GOMEZ, M.V.(1), KALAPOTHAKIS, E.(1)

(1)Laboratório de Biologia Molecular de Toxinas, Departamento de Farmacologia, ICB, UFMG, Belo Horizonte, MG, (2)Laboratório de Microscopia Eletrônica, Departamento de Biologia Celular, ICC, UnB, Brasília, DF, (3)Departamento de Patologia Básica, Setor de Ciências Biológicas, UFPR, Curitiba, PR, (4)Departamento de Bioquímica e Imunologia, ICB, UFMG, Belo Horizonte, MG.

It is estimated that, every year, 40% of the world’s agricultural production is lost due to the attack of pests. Although efficient and easily accessible to farmers, chemical insecticides can favor the development of resistant insects populations besides causing damage to the environment as well as men. Bioinsecticides represent an alternative for the reduction of agricultural losses, providing advantages concerning costs, ecology and human health. Our group, aiming the production of highly efficient bioinsecticides, has characterized toxins with possible insecticidal activity from a Loxosceles intermedia venom gland cDNAlibrary. The practical limitations to get from the crude venom high yields of previously identified neurotoxins made necessary the use of heterologous expression systems. In this work, cDNAs from two new putative insecticidal toxins, called LiTx1 e LiTx2, were identified, characterized and cloned in the transfer vector pSynXIVVI⁺ of the Baculovirus expression system. This is one of the most powerful and versatile eukaryotic expression systems available. Its advantages includes functional activity of the recombinant protein, post-translational modifications and high expression levels, among others. Sequencing analysis confirmed the success of all the procedures conducted so far to obtain the recombinant Baculovirus. Bioassays with the new recombinant toxins will be a important step in discovering new tools for pest control.

Supported by: CNPq, PADCT, PIBIC, Pronex, FAPEMIG.

CORRESPONDENCE TO:

CibeleSoares de Castro, Rua Fluorina, 1286/301, Belo Horizonte, MG, CEP: 30270-380, Brasil, Email: cscastro@brfree.com.br