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Studies of the action of the natural toxin ricin decrypted
Some plants contain dangerous toxins that can endanger the health of humans and animals. The plant poison called ricin is one of the most toxic occurring in nature proteins. Even the smallest doses of ricin may cause death. The extremely dangerous poison is produced by the plant Ricinus communis. Researchers now succeeded in deciphering the mode of action of ricin in an investigation. With the new research results, the scientists developed for the first time approaches for an effective antidote for ricin.
Researchers at the Institute of Molecular Biotechnology (IMBA) in Vienna have now succeeded in developing approaches for an antidote for one of the most toxic proteins (ricin) in nature. The physicians published the results of their study in the journal "Cell Research".
For poisoning with ricin, there is still no antidote that can prevent the death of those affected. Scientists now succeeded for the first time to understand the mode of action of the deadly toxin. This could lead to initial approaches to the development of an antidote. (Image: Herrndorff / fotolia.com) Small amounts of ricin can cause death within 72 hours
Ricin is a very toxic monosubstance, which naturally occurs in the plant Ricinus communis (also called Rizinusstaude or Wunderbaum). Ricin is so toxic that even the smallest doses can kill within 36 to 72 hours. Surely we surprise some people that such a poisonous plant is growing in many of our public parks and gardens.
Physicians are investigating rare disease that makes those affected resistant to ricin
Researchers have now been able to decode the effects of ricin. For the first time, the experts were able to develop the approaches for a possible antidote. They succeeded in doing so by studying an extremely rare disease that occurs in very few people, and apparently makes them resistant to the dangerous toxin ricin. The toxin ricin has been used several times in attacks as a biological weapon. For example, ricin was found on letters addressed to Barak Obama dating back to 2014.
Ricin destroys the ribosomes in the body
So far, there is no antidote for ricin. However, this could change in the near future. By deciphering the action of ricin, the experts have come a step closer to an antidote. As soon as ricin enters the organism, the toxin unfolds its complete toxic effect there. The poison begins to destroy the so-called ribosomes (cells in the protein factories). This attack ends fundamental processes of life, researchers say. It is then only a matter of time before death occurs.
Ricin needs sugar to develop its deadly effect
For several years, doctors have been looking for ways to make an effective antidote for ricin. The scientists now found that ricin needs some sort of sugar access code to develop its toxic effects. Two special genes have been identified that make ricin such a poisonous bioweapon. The genes Fut9 and Slc35c1 are involved in the regulation of a particular sugar metabolism in the cell, the researchers say.
What effect does fucose have on our proteins??
Fucose binds to existing proteins. Important: It is not fructose (fructose). Thus, the essential simple sugar fucose can change the shape and function of the affected proteins. Fucose also binds to the proteins of the cell wall. That's why sugar influences the communication and transport between the cells and their environment.
Researchers find out about which contact points cell toxins penetrate into the cells
By researching ricin and other cell toxins, researchers can gain important insights into the molecular characteristics of a cell. For example, the doctors found out which contact points use cytotoxins such as ricin to penetrate the cells in the body. In addition, it has been possible to observe how a cell poison reaches its exact location in the cell, where it then begins to prevent the vital processes. By understanding the effects of ricin, it may be possible to develop ways to protect cells from the effects of ricin, say the researchers.
Is it possible to block certain genes to prevent the effects of ricin??
If the two genes, called Fut9 and Slc35c1, are responsible for the lethal effects of ricin, blockage of these genes might prevent the damage by ricin, the researchers say. If the toxin gets into the cells through these genes and influences the transport system there, in order to get to the ribosomes and destroy them, a blockage could annul the entire process, explain the experts. The poison needs sugar to get to the ribosomes and do its fatal damage there. A characteristic sugar signature on the cell wall is needed by the poison to bind to the cell wall, explains co-author Jasmin Taubenschmid from the Institute of Molecular Biotechnology (IMBA) in Vienna.
The interaction between sugar and proteins should be investigated more closely
In the current study, scientists also found new information about the relationship between sugar and proteins, for which a variety of fundamental biological processes play an important role. In the past, proteins and sugars were researched separately in different studies. In view of the new results, it is now clear that, above all, the interaction between sugar and proteins has to be analyzed. Johannes Stadlmann.
Without sugar, ricin is not toxic to the body
In order to understand the mechanism of action behind ricin, various specialists from the University of Münster and the University of Heidelberg worked together. The cell samples used came from a patient with a very rare genetic defect, in which the so-called fucose metabolism does not work properly, explain the experts. Without sugar, ricin is therefore not toxic to the body. The research of rare diseases often leads to such amazing findings, which could help a large number of people in the future, adds author Josef M. Penninger. The rare disease of fucose metabolism researched in the study occurs only in three known cases worldwide. (As)