called radiation-resistant bacteria Deinococcus radiodurans It can withstand radiation doses thousands of times higher than what would kill a human. The secret behind this resistance is the existence of a collection of simple metabolites that combine with manganese to form a powerful antioxidant. Now, Northwestern University professor Brian Hoffman and his colleagues have discovered how this antioxidant works.
First discovered in 1956, Deinococcus radiodurans It is one of the most radiation-resistant organisms known.
It was isolated in an experiment aimed at determining whether high doses of gamma rays could be used to sterilize canned food.
In a new study, Professor Hoffman and co-authors characterized a synthetic designer antioxidant called MDP. Deinococcus radiodurans'Resilience.
They show that the components of MDP, manganese ions, phosphates, and small peptides, form a ternary complex that is a much more powerful protector from radiation damage than when manganese is combined with other individual components alone. I discovered that.
This discovery could ultimately lead to new synthetic antioxidants specifically tailored to human needs.
Applications include protecting astronauts from intense space radiation during deep space missions, preparing for radiation emergencies, and producing radiation-inactivated vaccines.
“This ternary complex is MDP's excellent shield against the effects of radiation,” said Professor Hoffman.
“It has long been known that manganese ions and phosphates together make a powerful antioxidant, but now we discover and understand the 'magical' potency brought about by the addition of a third ingredient. That's a breakthrough.”
“This study provided the key to understanding why this combination is such a powerful and promising radioprotector.”
In a previous study, researchers found that: Deinococcus radiodurans It can withstand 25,000 Grays (or units of X-rays and gamma rays).
But in a 2022 study, Professor Hoffmann and his team found that this bacterium, when dried and frozen, can withstand 140,000 Gy of radiation, 28,000 times the dose that would kill humans. did.
Therefore, if there are dormant frozen microbes buried on Mars, they may have survived the onslaught of galactic cosmic radiation and solar protons to this day.
In an effort to understand radioresistance in microorganisms, researchers investigated a designer decapeptide called DP1.
When combined with phosphate and manganese, DP1 forms the free radical scavenger MDP, which protects cells and proteins from radiation damage.
Professor Michael Daly, from Uniformed Services University, said: “This new understanding of MDP could lead to the development of even more powerful manganese-based antioxidants with applications in areas such as medicine, industry, defense and space exploration. Yes,” he said.
of result will appear in Proceedings of the National Academy of Sciences.
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Hao Yang others. 2024. A ternary complex of Mn2+, synthetic decapeptide DP1 (DEHGTAVMLK), and orthophosphate is an excellent antioxidant. PNAS 121 (51): e2417389121;doi: 10.1073/pnas.2417389121
Source: www.sci.news
