Scorpions and other venomous creatures have somewhat of a PR problem.
Staring down at a scorpion, pincers raised and tail poised for attack would strike fear in the hearts of many. But what if the venomous telson at the end of its tail held the answer to crippling diseases?
Deep in the corridors at the ANU Research School of Biology, sandwiched between experimental laboratories Professor Shin-Ho Chung and his team in the Computational Biophysics Group are using terabytes rather than test tubes to figure out the ins and outs of cell biology, including whether venom can be used for good.
The group is using the NCI’s supercomputer to understand biological ion channels – intelligent molecular gate keepers, confining some molecules inside cells and allowing others to flow through.
“It is only in the past several years that we are beginning to understand the three-dimensional structures of the protein controlling the channel, how the gate opens and closes and the way atoms navigate across when the gate is open,” explains Chung.
When these proteins malfunction, they give rise to numerous neurological, muscular and autoimmune diseases. In a case of foe becoming friend, the team is looking to venomous animals for answers. Scorpions, spiders, snakes and worm-hunting cone snails produce a vast array of toxins in their venom which target certain types of ion channels to quickly paralyse prey.
Dr Rong Chen, who joined Chung’s group last year, has been investigating the way in which these toxins interact with ion channels and plans to modify the toxin’s structure to block a specific channel type. Chen has already succeeded in creating a modified scorpion toxin which targets the ion channel known as Kv1.3 – implicated in autoimmune diseases such as rheumatoid arthritis and diabetes.
“There is a genuine possibility we will be able to find compounds, specifically targeted for certain ion channels, which can cure several debilitating disorders,” says Chung.
The understanding Chung’s team has gained in looking at how toxins affect the biological ion channels goes beyond drug discovery. Group member Dr Tamsyn Hilder is focusing on designing nanotubes – synthetic tubes, similar in diameter to biological ion channels, which have the ability to mimic some of the same functions. These exquisitely designed hollow pores have broad potential applications from ultra-sensitive biosensors to the treatment of bacterial infections.
“We have been able to design carbon nanotubes which broadly mimic some of the basic functions carried out by complex biological ion channels” explains Chung. “One such prototype nanotube only lets through positively charged ions, such as potassium and sodium. It mimics the function of antibiotic compounds produced by a type of bacteria that lives in soil, known as gramicidin.”
Hilder and Dr Dan Gordon have succeeded in designing simple nanotubes which selectively allow water molecules to pass across the cell membrane, preventing the salt from seawater getting through.
“These nanotubes may form part of a desalination membrane to more efficiently remove salt from seawater,” says Chung. “Not all research needs to be experimental. In fact, sometimes using a computational method is the best way – some experiments just aren’t practical. Computational research can be more cost effective, faster and can prevent unnecessary animal testing. We are solving real world problems virtually,” Chung concludes.
By Casey Hamilton. This article was first published in ANU Reporter.