Scientists at Ohio State University have made a novel discovery that could one day lead to new therapies for healing sunburned skin.
In nature, DNA avoids damage by converting UV rays into heat. Sunscreen lotions protect us by reflecting sunlight away from the skin, and also by dissipating UV as heat.
Ultraviolet (UV) light damages skin by causing chemical bonds to form in the wrong places along the DNA molecules in our cells. Normally, other, even smaller molecules called photolyases heal the damage.
Sunburn happens when the DNA is too damaged to repair, and cells die.
Photolyases have always been hard to study, because they work in tiny fractions of a second.
In the new study, lead researcher Dongping Zhong and his colleagues used ultra-fast pulses of laser light to spy on a photolyase while it was healing a strand of DNA.
They were able to see the enzyme's motion to help the healing process as it happens in nature.
"Now that we have accurately mapped the motions of a photolyase at the site of DNA repair, we can much better understand DNA repair at the atomic scale, and we can reveal the entire repair process with unprecedented detail," said Zhong.
The findings could be used to design drugs to heal sun damage.
The study appears in Proceedings of the National Academy of Sciences.