All plants and most animals have photolyase to repair severe sun damage. Everything from trees to bacteria to insects enjoys this extra protection. Only mammals lack the enzyme.
Humans do possess some enzymes that can undo damage with less efficiency. But we become sunburned when our DNA is too damaged for those enzymes to repair, and our skin cells die. Scientists have linked chronic sun damage to DNA mutations that lead to diseases such as skin cancer.
Now that researchers know the mechanism by which photolyase works, they might use that information to design drugs or lotions that heal sun damage, Zhong said.
Normal sunscreen lotions convert UV light to heat, or reflect it away from our skin. A sunscreen containing photolyase could potentially heal some of the damage from UV rays that get through.
Perhaps ironically, photolyase captures light of a different wavelength -- visible light, in the form of photons -- to obtain enough energy to launch the healing electron and proton into the DNA that has been damaged by UV light.
Researchers knew that visible light played a role in the process -- hence the term "photo" in the enzyme's name -- but nobody knew exactly how, until now.
|Contact: Dongping Zhong|
Ohio State University