Featured Research

from universities, journals, and other organizations

New way to study how enzymes repair DNA damage

Date:
February 8, 2010
Source:
Ohio State University
Summary:
Researchers have found a new way to study how enzymes move as they repair DNA sun damage -- and that discovery could one day lead to new therapies for healing sunburned skin. Ultraviolet (UV) light damages skin by causing chemical bonds to form in the wrong places along the DNA molecules in our cells.

Dongping Zhong.
Credit: Image courtesy of Ohio State University

Researchers at Ohio State University have found a new way to study how enzymes move as they repair DNA sun damage -- and that discovery could one day lead to new therapies for healing sunburned skin.

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, in part because they work in tiny fractions of a second. In this week's online edition of the Proceedings of the National Academy of Sciences, Ohio State physicist and chemist Dongping Zhong and his colleagues describe how they used ultra-fast pulses of laser light to spy on a photolyase while it was healing a strand of DNA.

This is the first time that anyone has observed this enzyme motion without first attaching a fluorescent molecule to the photolyase, which disturbs its movements. 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 Robert Smith Associate Professor of Physics, and associate professor in the departments of chemistry and biochemistry at Ohio State.

Such small motions are very hard to study. Typically, researchers deal with the problem by attaching tiny bits of fluorescent molecules to the enzymes they are trying to study. But adding an extra molecule to an enzyme such as photolyase could change how it moves.

"Once you tag it, you can't be sure that the motions you detect are the true motions of the molecule as it would normally function," Zhong explained.

So instead of using tags, he and his team took laser "snapshots" of a single photolyase in action in the laboratory. They mapped the shape and position of the photolyase molecule as it broke up the harmful chemical bonds in DNA caused by UV light. The whole reaction lasted only a few billionths of a second.

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.

Sunburn happens when the DNA absorbs the UV energy instead of converting it to heat. This is due in part to the random position of the DNA molecule within our cells when the UV hits it. When the UV energy is absorbed, it triggers chemical reactions that form lesions -- errant chemical bonds -- along the DNA strand.

If photolyases are unable to completely repair the lesions, the DNA can't replicate properly. Badly damaged cells simply die -- that's what gives sunburn its sting. Scientists also believe that chronic sun damage creates mutations that lead to diseases such as skin cancer.

The work in Zhong's lab is fundamental to the understanding of how those molecules interact. Other researchers could use this information to design drugs to heal sun damage.

"Of course, the ultimate goal of studying DNA repair is to help design artificial systems to mimic it," he said.

This work was funded by the National Science Foundation, the National Institute of Health, the Packard Foundation and the Sloan fellowship.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "New way to study how enzymes repair DNA damage." ScienceDaily. ScienceDaily, 8 February 2010. <www.sciencedaily.com/releases/2010/01/100128165129.htm>.
Ohio State University. (2010, February 8). New way to study how enzymes repair DNA damage. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2010/01/100128165129.htm
Ohio State University. "New way to study how enzymes repair DNA damage." ScienceDaily. www.sciencedaily.com/releases/2010/01/100128165129.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins