The painful toxins, controlled by a giant Australian sting tree, are surprisingly similar to the venom found in spiders and cone-shaped snails, researchers at the University of Queensland have found.
The Gympie-Gympie sting tree is one of the most poisonous plants in the world and causes extremely prolonged pain.
Associate Professor Irina Vetter, Dr. Thomas Durek and their teams from the UQ Institute of Molecular Biology have discovered a new family of toxins, which they called “hyptetides”
The scientific name of the tree is Dendrocnide, which literally means “living tree” – a member of the nettle family, which can be found in Australia from the Northern Rivers region of NSW, through the QYD of Gympie and all the way to the top of the Cape York Peninsula.
“Australian stinging tree species are particularly known for producing excruciatingly painful stings that, unlike those of their European and North American relatives, can cause symptoms that last for days or weeks.
“Like other stinging plants such as nettles, the giant stinging tree is covered with needle-like appendages called trichomes, which are about five millimeters long – trichomes look like fine hairs, but actually act like subcutaneous needles that inject toxins when in contact. with skin, “said Associate Professor Wind.
Historically, small molecules in trichomes such as histamine, acetylcholine and formic acid have been tested, but their injection does not cause severe and prolonged pain to the stinging tree, suggesting that an unidentified neurotoxin has been detected.
“We were interested in finding out if there were any neurotoxins that could explain these symptoms and why Gympie-Gympie could cause such long-term pain,” said Associate Professor Veter.
The team did discover such neurotoxins – a completely new class of miniproteins that they named “Gympietides” after the local name of the plant.
“Although derived from a plant, hympitids are similar to spider and cone snail toxins in the way they fold into their 3-D molecular structures and target the same pain receptors – this may make the hippie tree Hippie is a really “poisonous” plant.
Associate Professor Veter said that the long-lasting pain from the stinging tree can be explained by the fact that gymnasts constantly change the sodium channels in the sensory neurons, and not because of the fine hairs stuck in the skin.
“By understanding how this toxin works, we hope to provide better treatment for those who have been stung by the plant to relieve or eliminate the pain,” she said.
“We can also use the hypeptides as a skeleton for new therapeutics for pain relief.”
Since these plant and animal toxins have a common method of causing pain, the question arises when and how did these toxins develop?
Researchers point to two possibilities for the evolution of the toxin, either from the ancestral gene into an ancient shared ancestor, or from convergent evolution, where nature rediscovers the most appropriate structure to meet a common goal.
The research team hopes that gymnastics will provide new information on how pain-sensitive nerves function and contribute to the development of new painkillers.
The worst kind of pain you can imagine – what it’s like to be stung by a stinging tree
EK Gilding el al., “Neurotoxic peptides from the venom of the giant Australian sting tree,” Scientific progress (2020). advances.sciencemag.org/lookup … .1126 / sciadv.abb8828
Provided by the University of Queensland
Quote: Native stinging tree toxins coincide with the pain of spiders and scorpions (2020, September 16), extracted on September 17, 2020 from https://phys.org/news/2020-09-native-tree-toxins-pain -spiders.html
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