Study Spotlights a Natural Infection Fighter
THURSDAY, Jan. 3 -- The human body makes its own hydrogen peroxide --- the same disinfectant found in many first-aid kits and bathroom cabinets -- to help fight infections and keep cells healthy.
But when levels of hydrogen peroxide in the body get too high, this can endanger cell structures.
Now, researchers at Wake Forest University School of Medicine, in Winston-Salem, N.C., have released a detailed description of the way in which two proteins work together to keep hydrogen peroxide levels where they should be.
Writing in the Jan 3 issue of Nature, they describe the activity of a molecule called peroxiredoxin (Prx), which helps keep hydrogen peroxide levels below the amount that would cause damage to cellular structures. According to the researchers, Prx turns extra hydrogen peroxide into water, but when levels of the compound are very high, Prx starts calling on other proteins to help with the task.
"It basically acts as a sensor and warns the cell that levels are too high, and that the cell needs to respond," lead author Thomas J. Jonsson, a postdoctoral fellow at Wake Forest, said in a prepared statement. "Once that threat is gone, Prx needs to go back to its normal state."
The question the team wanted to answer was how Prx returned to its normal state. Previous research indicated that a protein called sulfiredoxin (Srx) participated in that process. The team used X-ray crystallography to understand how Srx worked with Prx. The technology allowed the team to capture the process in three dimensions.
What the research team found is a process they refer to as an "embrace": Prx unfolds, flips around and attaches itself to the back of Srx. That embrace creates a chemical reaction that repairs Prx.
According to the researchers, understanding the ways in which proteins work to keep cells healthy may give insight into the way in which damage occurs when the process does not work correctly.
Posted: January 2008