22 July 2007

Snail venom: Boo

Following up on the last post, the darker side of snail venom:

Powerful New Poison found in Deadly Sea Snails
By Aaron Rowe EmailJuly 11, 2007 | 8:00:00 AMCategories: Biology, Medicine & Medical Procedures

Conusparius Spies with a penchant for exotic poisons can add a new one to their list – snail venom.

For more than 23 years, Professor Baldomero M. Olivera has been studying snail venom. This week, his team at the University of Utah reported their discovery of a completely unique neurotoxin in Conus parius, a mollusk that hunts along the coast in the Philippines.

Some sea snails produce poisonous darts to hunt small fish and defend themselves. For the past 35 years, scientists have been studying these powerful neurotoxins. All of them are peptides, short strings of amino acids that make up miniature proteins.

Cone snail venoms are more than an elaborate tool for assassination. In 2004, one of those toxins was approved by the FDA to treat chronic pain. Some day, they may be used to treat a variety of neurological disorders including Alzheimer's and Parkinson's.

In the journal Biochemistry, Baldomero and his colleagues Russell Teichert and Elsie Jimenez compared this new poison to the others that have been identified in the past two decades. All of them impair the function of neuromuscular nicotinic acetylcholine receptors. In other words, they inactivate a protein found in the nerve cells that control muscle movement.

To identify the unique neurotoxin, the biologists cut out the venom ducts from several snails, froze them, pulverized them, and then extracted the peptides from the pulp with a mixture of water and the solvent acetonitrile. They purified the peptide and used a machine to determine its amino acid sequence. Later, they injected mice and goldfish with the purified peptide to prove that it is in fact the deadly poison. They were right. A tiny amount would kill goldfish within ten minutes and mice within thirty.

Perhaps this new poison will also find its way into the hospital -- or at least the next James Bond film.

HT: Slashdot