A new chemical isolated from spider venom might one day prevent human brain cells from dying after being deprived of oxygen for short periods, a Cornell chemist believes.
Jerrold Meinwald, professor of chemistry and chemical biology, told the American Chemical Society meeting that smoke-inhalation or stroke can cause overproduction of amino-acid neurotransmitters, possibly resulting in brain damage. "What this venom could do is block the effect of the overproduction of some of the neurotransmitters," he said. "In effect, we're turning off the receiver."
The new neuroactive chemical, known as HF-7, originally was isolated from the venom of the funnel-web spider, Hololena curta. The work was a collaboration of chemists at Cornell, Leiden University in the Netherlands and Cambridge Neuroscience Inc., a pharmaceutical firm in Cambridge, Mass.
Until the discovery of HF-7, it was thought that all spider venom components were amino-acid based. However this venom is based on a nucleic acid building block, Meinwald said: "It was a genuine surprise. We had no idea at all that this toxin was made from a nucleic acid component."
Describing his search for this neuroactive chemical, Meinwald said, "Looking for a needle in a haystack is easier. There you just get a big magnet and you'll find it. Looking for this chemical, we didn't know what we'd find. We didn't know what kind of structure we were looking for."
HF-7 works in the brain by blocking one in a family of receptor molecules called kainate receptors, which act as gates in nerve cell membranes. Theoretically, during short bouts of oxygen loss, HF-7 should stave off severe brain damage. However, it is not clear if the synthesized venom can break through the blood-brain barrier.
The original characterization and synthesis of HF-7 were done at Cornell by graduate students Kevin and Jinping McCormick and elaborated by Yingbo Li, a graduate student, and Bruce Ganem, Cornell professor of chemistry.
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