Peroxiredoxins are a group of protein-based antioxidant enzymes that are found in an organism’s cells. These enzymes facilitate the signal transduction within the organism’s cells, causing a physiological response at the organism’s cellular level. The enzymes also control the peroxide levels found in cells, by controlling other proteins known as cytokine, which ultimately produce the cells’ peroxide.
Researchers have determined that peroxiredoxins perform several vital functions in mammal organisms. In fact, lab mice that have low or no peroxiredoxins present in their blood supply have suffered as a result from anemia as well as hemopoiesis or blood-born cancers. The lower amounts of the enzyme can also effectively shorten the life of some lab mice by making them more susceptible to infection or disease. Other lab mice suffer from oxidative stress, or their bodies’ inability to remove toxins from the oxygen supplied to the cells.
Other vital functions that take place in mammals and other organisms are controlled or facilitated by peroxiredoxins. For example, the enzymes found in plants protect against oxidation in the cells that are part of the plant’s photosynthesis system. With mammals, the enzymes regulate events such as the death of cells, the production of new cells and the passing of impulses from one cell to another.
The levels of peroxiredoxins found in an organism’s cells are regulated by changes in phosphate levels or oligomer levels in the organism. Enzyme levels in an organism can also be affected by any chemical reactions in the organism that alter the oxidation state of atoms, such as when carbon is oxidized and produces carbon dioxide. An organism continues to recycle the enzymes in its cells, rather than constantly producing new enzymes.
The enzymes in the peroxiredoxins family can be found not only in mammals, but in other organisms as well. Mammals produce six different types of the enzymes in the family, while E. coli produces only three different types. In mammals, the enzymes can constitute up to one percent of the total amount of proteins found in an organism’s cells.
A organism’s body’s “clock” or circadian rhythm is also regulated by the peroxiredoxins present in the cells. The circadian rhythm is the 24 hour biological clock that drives physiological and behavioral functions in various organisms, including in mammals and plants, which are independent of environmental cues such as when the sun rises or sets. Even though other elements in a body contribute to the circadian rhythm, researchers have determined that these enzymes have regulated the circadian rhythm in mammals longer than any other known element.