Poster 053 - Proteomic analysis of the venom from the Amazonian scorpion Tityus cambridgei

Poster 53. 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.412.

1 Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico. 2 Department of Physiology, Medical School, National Autonomous University of Mexico, Ciudad Universitaria, Mexico D.F. 04510, Mexico. 3 Istituto di Biofisica, C.N.R., via De Marini 6, 16149 Genova, Italy.

Scorpion venoms are complex mixtures of peptides, known to cause impairment of ion-channel function in biological membranes. The chemical composition of T. cambridgei venom until recently was poorly known, despite the fact that it is the most dangerous Amazonian scorpion and many serious envenomation cases of humans have been reported. The purpose of this study is to perform a large-scale protein characterization and evaluate the pharmacological properties from the T. cambridgei venom components. In this work, the venom components were separated by HPLC to homogeneous form and analyzed by automatic Edman degradation and mass spectrometry. Electrophysiological measurements were performed using the patch clamp technique with different types and sub-types of K⁺ and Na⁺ ion channels. The mass fingerprint obtained by both, ESI-MS and MALDI-TOF/MS technologies, revealed more than one hundred different molecular masses varying from 255.1 to 27058.7 a.m.u. in this venom (J. Chromat B, 2004, 803, 55-66). Automatic Edman degradation and MS/MS allow us to obtain partial amino acid sequence of 26 toxins, and full sequence of seven different toxins. Electrophysiological measurements showed selective and potent action in both K⁺ and Na⁺ channels. Tityuscambridgei venom, like others Tiytus species, present a very complex mixture of peptides and proteins with a wide range of molecular weights and pharmacological activities, constituting a rich source of compounds of biotechnology interest as well as models to design new drugs.

Support: CONACYT 40251-Q, DGAPA-UNAM IN20600-3 and Laboratorios Silanes S.A.de C.V.