Toxins from scorpions could lead to new drugs for neuromuscular disorders and cardiovascular disease.
Life-saving scorpions. I’m Bob Hirshon and this is Science Update.
Sodium ions are important to nerve function, and some toxins from venomous creatures bind to nerve cells, change how they interact with sodium, and either block nerves or overexcite them. In the wild, this can mean death or paralysis. But in the lab, these toxins are invaluable to learning about nerve function and producing life-saving drugs. In the Journal of General Physiology, Johns Hopkins researcher Frank Bosmans and his colleagues describe using scorpion toxin and a new sensor chip to identify promising drug candidates.
You can test thousands of compounds in a day, and if there’s one compound there that can displace the scorpion toxin, we could theoretically find a new drug.
Revealing which compounds target the same nerve site as the scorpion toxin could lead to new therapies for heart disease and neuromuscular disorders. I’m Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
The use of venom in medicine has been going on for centuries, back to Mithradates of Pontus, whose Black Sea empire challenged Roman power in the first century BCE. Mithradates and his team of investigators sought a universal antidote to neutralize all poisons, by ingesting a cocktail of tiny doses of toxins and antidotes. His regimen calls to mind the principles of immunization.
These days, scientists are studying the chemical properties of venom to determine whether or not they can be used to treat sodium channel diseases and disorders such as heart disease and epilepsy. One hurdle scientists are seeking to overcome is the size of the proteins that make up a sodium channel, which controls the flow of charged particles in and out of the cell. When these channels malfunction, they can cause serious problems, ranging from heart defects to epilepsy.
In research published in January 2014, Dr. Bosmans found that "helper" proteins that interact with sodium channels play a crucial role because they are capable of changing the response of the channel to certain compounds and they can be considered as drug targets. However, these proteins are large and complex, making them difficult to study.
To try to deal with this problem, Dr. Frank Bosmans and his colleagues at Johns Hopkins and Aix Marseilles University in France are conducting research to find out if scorpion venom can help find new drugs to correct sodium channel function. “Our idea was, can we take out just a little piece of that big molecule and study that in isolation,” explains Bosmans. “We needed a molecule that also interacts with that small region. For that we chose these scorpion toxins because they have evolved for millions of years to very specifically target a certain region within this sodium channel.”
By focusing on just that section, the team was able to search for other molecules that target the same area. The scientists were able to reproduce many copies of the fragment and attach them to sensor chips, which were used to screen potential drug molecules to see if any were capable of interacting with that part of the sodium channel and altering its activity. This process helps the team determine if the drugs would be useful in treating medical conditions caused by a malfunction of the sodium channels.
Now try and answer these questions:
- Why are scientists studying the chemical properties of venom?
- What does a sodium channel do?
- What can happen when a sodium channel malfunctions?
- Why are the "helper" proteins difficult to study?
- How did Dr. Bosmans and his colleagues try to deal with this problem?
- How do you think the techniques used by Dr. Bosmans and his colleagues can help advance the treatment of disease?
You may want to check out these other Science Updates to learn more about how scientists study animals to better understand humans:
- Dolphin Healing explores how dolphins heal remarkably well after massive shark bites.
- In Hamsters, learn how scientists are studying hamsters to learn about the roots of aggression.
The ideas in this Science Update are somewhat complicated, but if your students have studied human biology and cells, they should be able to visualize the sodium channels the scientists are studying. You may want to remind students that the things these scientists are studying are microscopic and require the use of microscopes and other technology. This Scorpion Venom image may help your students understand the concepts presented in this Science Update.
You can extend on the concepts in this resource by helping your students explore how scientists are looking to animals for clues on how to combat osteoporosis in Bear Bones.