UMR 6560, Biochimie-Ingénierie des Protéines, IFR Jean Roche, Faculté de Médecine Secteur Nord, Boulevard P. Dramard, 13916 Marseille Cedex 20, France.
It is nowadays something of a truism to state that natural toxins are considered as essential tools for the study, at the molecular level, of their pharmacological targets. This implies to first solve numerous problems concerning their purification, their mode of action and their specificity in order to get reliable results with a specific target, within a given tissue. Considering scorpion and snake venomous secretions, a few exemples will be developped leading to the characterization and the successful use of very highly toxic and specific polypeptide neurotoxins.