Enzyme insights could lead to better sunburn treatments

Insects, fish, amphibians, marsupials and even bacteria have something that mammals lack, and it's an enzyme that we humans could use during these hot summer days. It's called photolyase and it repairs DNA after it's been damaged by ultraviolet rays. Researchers at the Ohio State University have been working for about 10 years on figuring out exactly how photolyase does its magic. In the Proceedings of the National Academy of Sciences, they discuss how they have, at last, witnessed the entire process in a lab. This knowledge, they say, could lead to better drugs or lotions to heal sunburns in people.

Here's what they did. Dongping Zhong, an Ohio State professor, and his colleagues took a movie of the enzyme using a kind of superfast strobe light that froze the action in time scales of between a few pico-seconds to nearly a nano-second. They discovered the secrets behind a two-step process by which photolyase fixes sunburned DNA by tearing it open in two places and reforming it into its original shape.

"The enzyme needs to inject an electron into damaged DNA--but how?" Zhong said in a statement. "There are two pathways. One is direct jump from the enzyme across the ring from one side to the other, which is a short distance. But instead the electron takes the scenic route. We found that along the way, there is another molecule that acts as a bridge to speed the electron flow, and in this way, the long route actually takes less time."

The researchers said their work could lead to development of a synthetic form of photolyase to treat humans' sunburns.

- read the release from Ohio State
- and the abstract in PNAS