-- Brown recluse spider venom is powerful enough to destroy human tissue, at times leading to gangrenous lesions. Now, after figuring out the venom's ingredient list, scientists are an important step closer to finding an antidote.
Spider venom concoctions have inspired everything from environment-friendly pesticides to treatments for arthritis and erectile dysfunction, so it's likely the newly identified recipe will have pharmacological applications beyond the cure for bites.
The study, published in this week's Proceedings of the National Academy of Sciences, found that brown recluse spider venom contains both big and small molecules.
Enzymes and proteins make up most of the "big" compounds, but lead author Frank Schroeder told Discovery News that he and his team identified "additional components that have been previously overlooked."
Schroeder, a scientist at Cornell's Boyce Thompson Institute and Department of Chemistry and Chemical Biology, and his colleagues discovered a new family of chemicals in the venom known as sulfated nucleosides.
These compounds, he explained, are based on one of the building blocks of RNA, a molecule in living cells that helps build proteins. A seemingly minor switch in an RNA component appears to contribute to the venom's toxic properties.
The researchers made the discovery after analyzing venom samples from more than 70 different types of spiders, including black widows and three members of the deadly recluse family: the Arizona, desert and brown recluse spiders. To obtain their samples, the researchers electrically stimulated a gland in the spiders that allowed the scientists to "milk" the venom.
The scientists then employed two high-tech methods -- proton nuclear magnetic resonance spectrometry and mass spectrometry -- that enabled them to look at the molecular structure of compounds, in this case, right down to their most basic components.
Although black widow and recluse spiders equally terrify most people, the scientists found that their venoms are very different.
"Our results show that black widow venom does not contain sulfated nucleosides," said Schroeder.
Instead, it seems that one of the hourglass-marked spider's most important venom ingredients is the deadly neurotoxin latrotoxin, which can invade a bite victim's cardiovascular system, as well as the muscles and nervous system.
The research "nicely demonstrates that molecules can be identified from mixtures without the often large amount of work involved in purification," said Arthur Edison, director of the Advanced Magnetic Resonance Imaging and Spectroscopy Facility and an associate professor at the University of Florida.
In fact, he pointed out that conventional purification methods would destroy the newly identified compounds, so the spectrometry method may be the best, and only, way to study such venoms.
Schroeder, who said he had spiders crawling on his laboratory notebooks during the research, can now create synthetic versions of the venoms, which will be used in future studies.
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