U.K.-led scientists have made a
discovery about snake venom that could lead to the development of new drugs to
treat a range of life-threatening conditions like cancer, diabetes, and high
blood pressure.
Most venom contains a huge
variety of lethal molecules called toxins, which have evolved from harmless
compounds that used to do different jobs elsewhere in the body. These toxins
target normal biological processes in snakes’ prey such as blood clotting or
nerve cell signaling, stopping them from working properly.
Now researchers have discovered
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.
NERC-funded researcher and lead
author of the study, Nicholas Casewell from Liverpool School of Tropical Medicine,
explains, “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.”
Scientists have long recognized
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.
But the researchers’ 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.
Snake researchers were aware that
venom toxins evolve from harmless molecules that do fairly mundane jobs
elsewhere in the body. But until now they had assumed that this was a one-way
process.
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.
Wolfgang Wüster from Bangor
University, a co-author of the study says, “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.”
The researchers’ findings are
published in Nature Communications.
Source: Bangor University
Filed Under: Drug Discovery
