[Structures and functions of animal toxins].

This brief review is devoted to the presentation of the major toxic proteins found in venoms of animals from five phyla. It is shown that various groups of venomous animals, including scorpions and snakes, produce toxins that exert different functions although they adopt a similar structure, suggesting that these toxins result from a divergent evolution. On the opposite, it is shown that toxins produced by animals from different phyla can exert similar functions even though they adopt unrelated structures, suggesting a convergent evolution. Finally, this review describes, at the molecular level, the functional and structural properties, including the dynamical characteristics, of a snake toxin which binds to the peripheral nicotinic acetylcholine receptor.