EPITOPE MAPPING AND SYNTHESIS OF PEPTIDES DERIVED FROM TSNTxP FOR THE PRODUCTION OF NEUTRALIZING ANTIBODIES AGAINST Tityus serrulatus SCORPION VENOM

Alvarenga, L., Machado, C., Granier, C., Chávez-Olórtegui, C.

Fundação Ezequiel Dias, Belo Horizonte, MG, Brasil and Institut de Biotechnologieet Pharmacologie, CNRS UMR 5094 Faculté de Pharmacie, Montpellier -France.

A non–toxin protein (TsNTxP) isolated from the venom of scorpion Tityus serrulatus(Ts) induces which antibodies cross-react with several toxins from the venom, in contrast to anti-toxin antibodies which are toxin specific. The use of defined synthetic epitopes could be used for the antivenom preparation and production of vaccines against scorpionism.

Objective: Use of Spot method of multiple peptide synthesis to identify epitopes derived from toxins of the Ts venom for the preparation of neutralizing antivenoms.

Materials and methods: The Spot-method was used to prepare immobilized overlapping peptides  covering the amino acid sequence of TsNTxP and TsIV, an a-type toxin of  the Ts venom. Rabbit  sera  anti-TsNTxP and anti-Ts IV were produced and their binding in the membrane was detected by using a alkaline-phosphatase conjugate anti-rabbit. The reactive peptides were synthesized as soluble peptides and coupled to KLH for use as immunogens.

Results: Three antigenic regions were discovered with anti-TsNTxP, one N-terminal, one central and the C-terminal part. One epitopein the C-terminal of Ts IV was identified and used for production of antibodies. Quantities of venom equivalent to 13.5 LD₅₀  were neutralized by 1 ml of the anti-peptide serum. The anti-peptide antibodies had a high reactivity against Ts venom, moderate binding for T. bahiensis, T. cambridgei, T. stimurus and were unable to recognize Androctonus australisand Centrutoides sculpturatus venoms.

Conclusion: These results show that peptides derived from the sequence of scorpion toxins appear to be an alternative for the antivenom preparation against  scorpionism.

Supported by: CNPq, INSERM. 

CORRESPONDENCE TO:

LarissaMagalhães Alvarenga, Rua Cardeal Stepnac 210/201, Belo Horizonte, MG, CEP: 31 170 220, Brasil, Email: lari_alvarenga@yahoo.com.br