superoksididismutaasille

Superoksididismutaasi, often abbreviated as SOD, is a crucial enzyme found in nearly all aerobic organisms, including humans. Its primary function is to catalyze the dismutation of the superoxide radical (O2•−) into oxygen (O2) and hydrogen peroxide (H2O2). The superoxide radical is a highly reactive and potentially damaging molecule that is a byproduct of normal aerobic metabolism. Without SOD, superoxide could accumulate and lead to oxidative stress, damaging cellular components like DNA, proteins, and lipids.

There are several different types of SOD, classified based on the metal cofactor they utilize. The most common are copper-zinc SOD (Cu/Zn-SOD), manganese SOD (Mn-SOD), and iron SOD (Fe-SOD). Cu/Zn-SOD is typically found in the cytoplasm of eukaryotic cells, while Mn-SOD is located in the mitochondria. Fe-SOD is prevalent in bacteria and some plant tissues. The dismutation reaction catalyzed by SOD is a vital defense mechanism against the harmful effects of reactive oxygen species.

The hydrogen peroxide produced by SOD is still a reactive species, but it is significantly less toxic than superoxide. It can then be further broken down into harmless water and oxygen by other enzymes, such as catalase and glutathione peroxidase. Therefore, SOD plays a central role in the cellular antioxidant defense system, protecting organisms from the damaging consequences of oxidative stress, which has been implicated in aging and various diseases.