The availability of an enzyme, known as the Lon protease, that protects cells from oxidative damage, declines as the body ages, a new study has found. The finding may help explain why humans lose energy with age and could point medicine toward new diets or pharmaceuticals to slow the aging process.
The researchers showed that when oxidative agents attack the power centers of young cells, the cells respond by calling up reinforcements of the enzyme, which breaks up and removes damaged proteins. As the cells age, they lose the ability to mobilize large numbers of Lon, the researchers reported.
Lon protects the mitochondria - tiny organisms in the cell that convert oxygen into energy. The conversion is never perfect: Some oxygen leaks and combines with other elements to create damaging oxidants. Oxidation is the process behind rust and food spoilage. In the body, oxidation can damage or destroy almost any tissue. Lon removes oxidized proteins from the mitochondria and also plays a vital role in helping to make new mitochondria.
"We know that mitochondrial function declines with age, which is a major limitation to cells. One of the components of that decline is the loss of Lon," said Senior author Kelvin J. A. Davies, a professor at the USC Leonard Davis School of Gerontology.
The ability of Lon to be induced by (oxidative) stress is a very important component of overall stress resistance," he added. The study has been published in The Journals of Gerontology .