Scitech  Spidey senses are tingling

Spider toxin creates a new opportunity for studying ion channels in the body

Recently, researchers from the University of California, Riverside have discovered a useful tool for developing drugs to treat pain and diseases like congestive heart failure: venom from the American funnel web spider.

The team, led by Xiao Zhang, professor of tumor development at the Del Web Centre for Neuroscience, purchased their spider venom in bulk instead of using the conventional “spider milking” technique to obtain the venom. This allowed the researchers to purify large amounts of the toxin to examine the way it interacts with ion channels. The information gained from the study may lead to the development of new drugs.

Every living cell comes equipped with a set of specialized proteins that govern the flow of ions in and out of the cell membrane. These proteins, called ion channels, are essential to the functioning of every organism: they control neural synapses, or the way the brain communicates with the body. A single cell contains over 300 types of ion channels, and when one stops functioning properly, the results can be fatal.

Tetrodotoxin (TTX) – the toxin found in raw puffer fish meat – will cause vomiting, muscle paralysis, and possibly death when consumed. It works by binding to sodium channels in nerve cell membranes, stopping the transmission of electrical signals to the muscles. Venom from the American funnel web spider works similarly to TTX, but blocks the calcium channel that is used to control the heartbeat and release hormones.

Ion channels are sometimes only one or two atoms wide at their narrowest point and, because of their small size, their structure has only recently been made clear. Researchers were able to observe the way toxins block channels to gain insight into the way the channels work, and to develop drugs to treat channels that have stopped functioning properly. When a new toxin is isolated, researchers have a new tool with which to study channels; in this case, it was the calcium channel.

While researchers have suspected the channel-blocking nature of the American funnel web spider’s venom for a decade, they have been unable to convert the toxin to a usable form.  In a phone interview with The Daily, Zhang said that in purifying and isolating the toxin, the team was able to overcome a “research barrier that has been blocking progress for ten years.”

The team hopes that with the information gained from this study, they will be able to isolate new toxins, and develop better drugs for heart failure, epilepsy, and pain.