CHARACTERIZATION OF STRUCTURE AND BIOLOGICAL ACTIVITIES OF NOVEL CROTAMINE ISOFORM ISOLATED FROM CROTALUS DURISSUS CASCAVELLA (MARACAMBOIA)

Toyama, M.H.(1), Oliveira, D.G.(1), Nogueira, T.C.A.(2), Rodrigues-Simioni, L.(3), Belian, L.O.S.(4), Carneiro, E.M.(2), Monteiro, H.S.A.(5), Martins, A.M.C.(5),Boschero, A.C.(2), Marangoni, S.(1)

(1)Departamento de Bioquímica, (2)Departamento de Fisiologia e Biofísica, (3)Departamento de Farmacologia, UNICAMP, (4)Instituto Biológico de São Paulo, Campinas, (5)Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará

Objectives: In this work we analyzed four Crotalus durissus cascavella venoms provide from the northeast region of Brazil and isolated a novel crotamine-like isoform from the one rattlesnake group found in Fortaleza (Ceará State).  Its primary structure, neurotoxic, insulin secretacogue, and bactericidal characterization was present.

Method and Results: Four Crotalus durissus cascavella rattlesnake venoms were analyzed in the molecular exclusion and reverse-phase HPLC.  The analysis of the venom reveled some differences between then, but the most significant differences it was found to venom from the Fortaleza. This venom showed a high content of crotamine and the Convulxinis not the major fraction. Its novel protein showed a 90% of homology with other small basic neurotoxins as crotamine isolated from Crotalus durissus terrificus.  It showed pH values of 9.5 and a molecular mass of 4.4 kDa.  This protein it was characterized by strong facilitation and pre-synaptic effect at doses of 1mg, 3mg and 5mg and 10 mg/ml (maximum response).  Using doses of 5mg this protein induced a strong insulin secretion in nom stimulated and stimulated state.  The neurotoxic as well insulin secretion was strongly inhibited by TTX.  This protein showed strong bactericidal effect in the both Gram-positive as well as in the Gram-Negative bacteria.

Conclusions: The geographical variation is very common to the Bothrops venom but there are lithe work described to Crotalic venom. C. durissus cascavella showed a significant variation to Convulxin content, the crotamine probably has important role to rattlesnake venoms found in Ceará and Crotoxin do not exhibit variation in its content but its subunits present significant variation.  This novel crotamine acts on the sodium channel of the nerve and other excitatory cell as B-cell isolated from the Langerhans islet from rodents.  Probably the bactericidal effect found to this crotamine is involving the sodium channel.

CORRESPONDENCE TO:

NOGUEIRA, T.C.A., Department of Physiology and Biophysics, Institute of Biology, State University of Campinas, Campinas, SP, Brasil, Email: tcan@bol.com.br