REACTIVITY OF NEUTRALIZING ANTIBODIES ELICITED BY NATURAL AND RECOMBINANT TsNTxP (Tityus serrulatus non toxic protein)

Mendes, T. M.(1), Kalapothakis, E.(1), Guatimosin, S. C.(1), Maria, W. S.(2), Granier C.(3) Chávez-Olórtegui, C.(2)

(1)Laboratório de Biologia Molecular de Toxinas, Departamento de Farmacologia, ICB, UFMG, BH, MG, Brasil, (2)FUNED, BH, MG, Brasil. (3)Institut Biotechnonogie et Pharmacologie, Université Montpellier, France

Inoculation of scorpion venom exerts noxious effects in experimental animals and in victims of scorpion stings. This venom elicits a complex patter of clinical signs and symptoms that can lead to death. The fractionation of the venom of T. serrulatus leads to the isolation of lethal, toxic and non-toxic components. Previously we have shown that the TsNTxPa non-toxic protein purified from the Tityus venom or the recombinant TsNTxp (recTsNTxp), can induce an increase in the level of circulating antibodies sufficient to neutralize the toxic effects of the venom. However, small differences between the antibodies generated against TsNTxp and recTsNTxp were observed. Thus, in order to identify the epitopes recognized by anti-TsNTxP native and anti-recTsNTxP antibodies, we prepared by methods of multiple peptide synthesis sets of overlapping continuous and discontinuous peptides corresponding to the amino acid sequence of TsNTxP.  At the end of the synthesis, the peptides remain covalently bound to the membrane and are simultaneously assayed for antibody reactivity. The pattern of binding given by antibodies generated with TsNTxP native or recombinant using mice, rabbit and sheep, showed to be different by the identification of distinct antigenic regions of the TsNTxP sequence. In conclusion, the results suggest that the structure adopted by recTsNTxP-MBP fusion protein does not resemble completely the conformation of the native protein. However, the antibodies generated against recTsNTxp were able to neutralize the venom of Tityus serrulatus.

Supported by: FAPEMIG, CNPq, Pronex, PADCT.

CORRESPONDENCE TO:

Thais Melo Mendes, Rua Líguria, 155, Belo Horizonte, MG, CEP: 31.340-360, Brasil, Email: taiamm@hotmail.com