Like snakes, some types of lizards are venomous. Because snake venom are already being investigated for their uses as pain relievers and clot busting drugs, researchers are now turning to lizard venoms to see what they can find that might have pharmaceutical potential.
Researchers at Aarhus University in Sweden have now made the first comprehensive description of all the proteins in the venom of gila monsters, the lizards commonly found in Mexico and the American Southwest. The study of all the proteins in a creature or in a substance such as venom is called proteomics.
A chemical called exendin-4 has already been extracted from gila monster venom. It is marketed as Byetta and is used in the management of type 2 diabetes. Other chemicals in the venom are being studied because they have been shown to affect memory and may be of use in treating Alzheimer's disease. By conducting a complete proteomic study of gila monster venom, other possible drugs may be identified. The work was complicated by the fact that the genome-the entire gene structure-of gila monsters has not been mapped as yet.
The Aarhus researchers have identified 19 proteins that were not previously known to exist in gila monster venom.
Gil monsters are the only venomous lizards in the United States. Unlike snakes, which can inject venom from fangs, gila monsters have their venom in their saliva. Their venom is quite poisonous, but there is relatively little venom in their bites so these bites are almost never deadly. Gila monsters are little threat to humans because they are also slow-moving creatures and easy to avoid. Gila monsters use their venom defensively and bit only when disturbed, unlike snakes which use their venom to attack and paralyze prey.
Similar proteomic work is being done on the venoms of spiders.