My brother has broken his arm twice already. Each time he went to the hospital to get an X-ray so doctors could see exactly where the fracture was. This radiation is great for showing us an image of our bones. But did you also know that X-rays can damage DNA?
Scientists have already uncovered several mechanisms for how X-rays cause DNA damage. Little is currently known about one of these mechanisms: damage via unpaired electrons. They form because X-rays first release electrons from molecules in our cells. This creates a cascade effect, and the loose electrons will in turn lose other electrons.
Most electrons find their place again after a while, but some can temporarily bind to DNA. These are unpaired electrons, so the name refers to this temporary bond. They occur not only on DNA, but actually in many molecules. For example, when a spaceship returns to Earth at high speed, the outer surface becomes very warm due to air resistance and millions of unbound electrons are formed. Unbound electrons usually leave the DNA without causing any damage. But sometimes it remains long enough to lead to rupture. If the cell does not repair this break, a cancerous tumor can eventually develop from it.
How does my research fit into this?
My research is the basis of the prevention method: I look for the position of the unbound electron in the hope that I can get information from this about exactly how the break occurs. I am not currently examining DNA molecules because they are too large, instead I am looking at a group of smaller molecules called chloroethenes. They can also contain unbound electrons that can cause an interruption. Recently I was able to locate the unpaired electrons of these molecules.
The next steps then are to characterize increasingly larger molecules, with the ultimate goal of calculating electron positions in DNA molecules. The road to preventing DNA damage caused by unpaired electrons is still a long way off. Once my part of the research is completed, medical scientists can begin working on finding an effective preventive method.
How exactly do I do this, determine the location of the electrons?
I can’t look at electrons with my naked eye or even with a magnifying glass or microscope because they are so small and move so fast. What I do is use calculations to build a model of molecules and their electrons. A regular laptop, like mine, is often not powerful enough to do this. That’s why I use a supercomputer! This consists of a series of individual but very powerful computers that work together to perform calculations.
From my laptop, I connect to this supercomputer and send it instructions. Small calculations are completed in a few minutes, while larger calculations take hours or even days. It then sends me the results back in the form of a text file containing a lot of data. Then it is up to me to process and interpret it. This branch of chemical research is also called computational chemistry, because computers are used instead of experiments. In my case, the end result is an image of the molecule, showing where the electrons are most often located.
What about unpaired electrons?
This process is difficult for unpaired electrons. The temporary binding of these electrons is difficult to describe using the most commonly used models, and often the result is that the electron has already left the molecule. It is as if the electron is trying to hide its temporary whereabouts.
My research consists of testing and extending existing but rarely used models. One of the advantages of computational chemistry is that we can modify the molecules in our models in ways that are not possible in experiments with real molecules. I change the properties of molecules in such a way that they exert a greater attraction on the unpaired electron. As a result, temporary bonds are no longer temporary but permanent.
In this way, the researchers could have already identified the energy difference in the molecule due to the unpaired electron. After expanding on this method and working for a long time, I also succeeded in determining the position of the unpaired electron, which was the first achievement in my research! A free preview version of this can be found at .
I’m excited to continue exploring and learning more about these fascinating unpaired electrons, and I hope you are too.
