The bacterium Deinococcus radiodurans can withstand extreme cold, acidity, complete dehydration, and incredible doses of radiation. Due to its astonishing resilience, researchers have nicknamed it "Conan the Bacterium" in honor of the immortal character from the fantasy film, as reported by ScienceAlert.
The secret of micro-Conan lies in its arsenal of highly effective antioxidants that eliminate oxygen radicals. These radicals can damage proteins that are critically important for the cell's repair process.
A team of scientists from Northwestern University and the U.S. University of Military Services (USU) decided to delve deeper into how these substances provide such high levels of protection.
As is known, radiation overloads the bonds in our biological mechanism, causing it to break down. Most living organisms on the planet have fairly effective repair mechanisms that eliminate damage in the most vital systems, such as genetic materials.
After bombardment by ionizing energy or dehydration, cells begin to rapidly fill with a toxic form of oxygen molecules. Such "superoxide radicals" can disrupt any repair mechanisms, leading to the accumulation of damage.
D. radiodurans, like many other organisms, tackles this problem using a blend of antioxidants. Some of these are based on the element manganese, which combines with other materials like phosphate. This cocktail effectively addresses the issue.
In earlier studies, scientists discovered a manganese-phosphate peptide, which they named MDP. It turned out to be one of the components of the organisms' protective shield. As a result, this peptide has been used in vaccines requiring gamma irradiation for sterilization.
The researchers aimed to better understand how the manganese-phosphate peptide remains so effective. They found that the triple structure of the combination of manganese, phosphate, and peptide surpasses all others.
"We have long known that manganese ions and phosphate together form a powerful antioxidant, but discovering the third element in this equation was a breakthrough. The research results provide a key to understanding why this combination is so powerful," say the authors of the study.
The scientists cite D. radiodurans, which can recover after absorbing 140,000 grays (a unit of measurement for the amount of energy absorbed by a substance due to radiation exposure). For comparison, it takes only 100 grays to send a human to the grave.
It is possible that the results of this discovery could be used in the future not only for drug development. Such advancements may help humans endure the stresses of traveling to Mars and beyond.
Additionally, another secret of the elusive "indestructible" tardigrades has been revealed. These tiny resilient creatures continue to amaze scientists—this time, they have learned how tardigrades search for mates and reproduce.