Chemistry of Venom: The Box Jellyfish

About the Box Jellyfish:

According to Dr. Angel Yanagihara, a biochemist and venom expert, “The box jellyfish is the most venomous animal in the world”. One box jellyfish in particular, the Chironex fleckeri, also known as the “sea wasp”, is Australia’s most dangerous jellyfish. This box jellyfish has a body about the size the of a basketball and has 60 tentacles that are 6.5 feet, or two meters, in length but can grow up to 10 feet. Don’t let the passive pale blue color of the box jellyfish fool you – they are known to have caused deaths as fast as 2 to 5 minutes.

The venom of the box jellyfish causes excruciating pain for the victims of the sting and often the outcome only leads to death. People have described that being stung by a box jellyfish produces an intense burning sensation and it feels like you are being branded with a red hot iron. Now that’s painful. The tentacles are adherent and wraps around the afflicted area. People that survive the envenomation will have marks on their body that look like they’ve been whipped. The area that was assaulted will most likely result in a permanent scar. But more often than not, if the victim is not treated immediately, there is no chance of survival.

What makes the box jellyfish so deadly?

The tentacles of the box jellyfish are lined with nematocysts, or special capsules containing a barbed, threadlike tube that delivers a paralyzing sting when propelled into something. These capsules are known to hold extremely venomous material that is considered lethal. The way that this venom is transported through the body is quite efficient as well, because once the dart pierces the skin, the cnidocyst shoots the toxin through the needle and into the victim. The toxin then enters the blood, where it can cause a dangerous spike in blood pressure, stop theheart, and kill the victim. For jellyfish, the box jellyfish is considered a very agile swimmer. This is due in part to its 24 eyes, which gives the jellyfish a wide range of vision.

The chemical composition of this venom, while not thoroughly known, consists of multiple proteins. There were toxins and proteins, specifically isoforms of the cnidarian proteins. Through the use toxin-specific stains and phosphoprotein/glycoprotein-specific stains, it is found that glycosylation is a common toxin in the venom. Glycosylation is the reaction where a carbohydrate is attached to a hydroxyl. Glycosylation is also the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules. Toxins include CfTX-1 and CfTX-2, two additional toxins, CfTX-A and CfTX-B, and a third putative toxin, CfTX-Bt.

Recently, Dr. Yanagihara and her colleagues at the University of Hawaii have shed light on the reason for the rapid cardiac arrest that occurs after being stung by the sea wasp. The research consisted of extracting the venom from the stingers and then separating the venom into its components. Each of the different components effects were tested on mice, and the results was that the “fast acting agent” is the molecule porin. This molecule punctures red blood cells in the human blood and the holes that are created causes potassium to leak out. When the potassium content in the blood reaches levels that are above the normal amount, this is called hyperkalemia. Hyperkalemia is not deadly when it is just mild, but when there is a substantial amount of potassium in the blood hyperkalemia reaches a lethal stage. Severe hyperkalemia can lead to cardiac arrest and then death.

In addition to identifying the root cause of rapid cardiac arrest, Dr. Yanagihara also proposes a way to counteract their effects. Her studies focus on the introduction of zinc gluconate which, hopefully, will prevent potassium from spilling out of red blood cells by disrupting porins.

Customary to this blog, we will briefly discuss the treatment involved in a box jellyfish sting. Medical professionals used to condone the use of bandages as a way of applying pressure to the affected region, as it was believed that these pressure bandages would reduce the distribution of the venom through the lymph and blood circulatory system. This method actually stimulated the region, causing nematocyst discharge. Until recently, it was believed that vinegar was a suitable solution to venom. The acetic acid in vinegar would deactivate undischarged nematocysts, preventing them from opening and releasing venom. This practice is no longer recommended after it was demonstrated after later studies that while vinegar deactivates unfired nematocysts, it causes already-fired nematocysts (which still contain some venom) to release the remaining venom. I guess the only chance you have would be to wish for the best of luck, as the Chironex fleckeri venom claims on average about 100 lives a year, and has a high fatality rate.

x over bandage.JPG

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