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Poster 103. Congresso da Sociedade Brasileira de Toxinologia, 8., Symposium of the Pan American Section of the International Society on Toxinology, 8., 2004, Angra dos Reis, Brasil. Abstracts... J. Venom. Anim. Toxins incl.Trop. Dis., 2004, 10, 3, p.462. |
The role of Natterin 2 in nociception and edema induced by Thalassophryne nattereri venom
1Bruni, F.M.: 1Magalhães G.S.: 1Moura-da-Silva A.M.: and 1Lopes-Ferreira, M.
1 Laboratório de Imunopatologia, Instituto Butantan, São Paulo, Brasil.
The accidents caused by the fish Thalassophryne nattereri (niquim) a serious medical, economic and social problem in the North and Northeast of Brazil. The venom induces severe edema and pain followed by a fast setting necrosis, both in human victims and experimental models. Recently a cDNA library was constructed with the glands of the fish. In this library, sequences of five most abundant clones were sequenced and identified as Natterins 1, 2, 3 and 4. Natterin 2 was cloned into expression vector and obtained as inclusion body, which was subsequently purified and used in immunization of rabbits. The anti-Natterin 2 antibody levels were assessed by ELISA using T.nattereri venom (1:256000) and Natterin 2 (1:512000) as antigens. The specificity was analyzed by Western Blotting recognizing total venom major bands of approximately 38 kDa. To assess the neutralization ability, the IgG fraction was isolated by Protein-A-Sepharose chromatography and it was pre-incubated with venom (3 mg of venom/30 mL of IgG for nociceptive and edematogenic activities, and 30 mg of venom/ 100 mL of IgG for necrosis activity) and then injected into mice. Our results showed that the IgG fraction anti-Natterin 2 neutralized 64% of nociception and 80% of edema but did not neutralize necrosis. These results show the important role of Natterin 2 in inducing nociception and edema in mice and point out the potential of recombinant proteins in producing efficient antivenoms.
Correspondence to: februni@hotmail.com