Production And Characterization Of Monoclonal Antibodies Against Tityus serrulatus Scorpion Toxins

Alvarenga, L.M.¹; Martins, M.S.²; Bertelli, M.¹; Machado de Ávila, R.A.¹; Granier, C.³; Chávez-Olórtegui, C.¹

1 Departamento de Bioquímica e Imunologia, 2 Departamento de Parasitologia, ICB, Universidade Federal de Minas Gerais CEP: 31270901, Belo Horizonte-MG, Brasil. 3 CNRS UMR5094^,, Institut Biotechnologie et Pharmacologie, Université de Montpellier I Montpellier-France.

Scorpion neurotoxins that act on ion channels share some structural features but differ in antigenic and immunogenic properties. They are highly structured peptides, 60-70 amino acids long. The development of monoclonal antibodies (mAb) against these toxins may help us to understand the fine antigenic specificity of these molecules and it’s mechanisms of neutralization. To obtain the mAbs, a toxic fraction (TstFG50) of the Tityusvenom (this G50 chromatography fraction represents most of the toxicity of the crude venom) conjugated to bovine serum albumin (BSA) with glutaraldehyde was used to immunize BALB/c mice. TstFG50 coupled to BSA yielded a thoroughly detoxified immunogen. The mAbs (16) were screened by enzyme-linked immunosorbent assay (ELISA) using TstFG50, and scorpion pure proteins such as TsNTxP (non toxic protein of Ts) and TsVII (b-toxin of the venom of scorpion Ts). We have used the Spot method of multiple peptide synthesis to prepare sets of immobilized overlapping peptides of uniform size (15 and 25 mer), covering the complete amino acid sequences of TsNTxP a non-toxic and immunogenic protein and TsVII thus to determine the epitope specificities recognized for the monoclonal antibodies. Two mAbs (4A11A6 and 4H9G10) presented neutralizing properties. The results indicated that the epitopes recognized by the two antibodies are probably conformation-dependents and are located in the active surface of toxins (both a and b toxins), which may suggest the protective character of both.

Supported by: CNPq, INSERM, FAPEMIG

Correspondence to: lari_alvarenga@yahoo.com.br