A study led by UK researchers found that the toxins that make snake and lizard venom deadly can evolve back into completely harmless molecules, raising the possibility that they could be developed into drugs.
Snake venom contains a huge variety of lethal molecules called toxins which target normal biological processes in snakes' prey such as blood clotting or nerve cell signalling, stopping them from working properly.
Scientists have long recognised that the way that toxins work makes them useful targets for drug discovery but the fact that they're harmful poses a problem. This means that drug developers have had to modify toxins to retain their potency and make them safe for drug use.
The new discovery that there may be many harmless versions of these toxins throughout a snake's body opens the door to a whole new era of drug discovery.
"Our results demonstrate that the evolution of venoms is a really complex process. The venom gland of snakes appears to be a melting pot for evolving new functions for molecules, some of which are retained in venom for killing prey, while others go on to serve new functions in other tissues in the body," lead researcher Dr Nicholas Casewell from Liverpool School of Tropical Medicine, said.
Casewell and colleagues from Bangor University and the Australian National University used recently published gene sequences from the Garter snake and the Burmese python in their study.
They compared these sequences with those from venom glands in a wide range of snakes and lizards, constructing an evolutionary tree to work out the relationships between the various sequences.
"Many snake venom toxins target the same physiological pathways that doctors would like to target to treat a variety of medical conditions. Understanding how toxins can be tamed into harmless physiological proteins may aid development of cures from venom," Dr Wolfgang W
