Navigation Links
Researchers find new way to study how enzymes repair DNA damage
Date:1/28/2010

COLUMBUS, Ohio -- 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.


'/>"/>

Contact: Dongping Zhong
Zhong.28@osu.edu
614-292-3044
Ohio State University
Source:Eurekalert

Related medicine news :

1. UCLA researchers image earliest signs of Alzheimers, before symptoms appear
2. Researchers find leukemia cells metabolize fat to avoid cell death
3. Hair Cloning Not Yet Recommended by Researchers Who Developed the Technique
4. Researchers develop new tool for gene delivery
5. Researchers at Meharry Medical College Find Green Tea Extract Showing Promise for Treatment of Uterine Fibroids
6. Researchers welcome new multiple sclerosis drug
7. Barrow researchers receive more than $2 million in NIH grants for nicotine studies
8. Researchers discover method to objectively identify PTSD
9. Researchers find a treatment for deadly brain tumor
10. Researchers find new insights into inherited retinal disease
11. Pitt researchers raise concern over frequency of surveillance colonoscopy
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/23/2017)... ... ... The physicians of KSF Orthopaedic Center PA are proud to announce the opening ... at 2255 E. Mossy Oaks Rd., Suite 440, Spring, Texas 77389 inside the new ... in the north Houston area (The Woodlands, Conroe, Magnolia, Kingwood, Humble) with an even ...
(Date:3/23/2017)... ... March 23, 2017 , ... PAINWeekEnd ... at 10 North Broadway Avenue, will be an educational and exciting program providing ... in the management of chronic pain. , Oklahoma is in a healthcare crisis. ...
(Date:3/23/2017)... ... ... of adults are unaware of the dangers that infectious bacteria play in mouth disease, while ... a day that dentists recommend. The ramifications of improper oral upkeep go far beyond bad ... 164 million hours of work each year due to dental issues. That is why Mediaplanet ...
(Date:3/23/2017)... ... March 23, 2017 , ... Benefits delivery trailblazer, ... mobile app and centralized benefits dashboard solving one of the top frustrations in ... locations. For the first time, employees can access up-to-date information and account balances ...
(Date:3/23/2017)... Malvern, PA (PRWEB) , ... March 23, 2017 ... ... a comprehensive educational training program owned and organized by HMP Communications Holdings, LLC, ... training program for physicians within its nationwide network of wound centers interested in ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... The key factors driving the growth of dialysis ... growth and increasing healthcare expenditure. Some of the noteworthy trends ... ESRD patients, rising demand for home PD treatment and huge ... market is hindered by high treatment costs and stringent regulations. ... Complete ...
(Date:3/23/2017)... March 23, 2017  Transportation Insight, a multi-modal lead ... supply chain management firm with expertise serving clients in ... Rick Zaffarano was named a 2017 ... Chain by the only publication exclusively dedicated to covering ... chain. "Rick has brought to Transportation Insight ...
(Date:3/23/2017)... INDIANAPOLIS , March 23, 2017  Eli ... the William Sansum Diabetes Center have established a research ... by diabetes through enhanced research, education and care. ... disease bears a disproportionate weight on Latino families in ... David Kerr , M.D., FRCPE, director of Innovation and ...
Breaking Medicine Technology: