SOD2 In-Depth

The enzyme superoxide dismutase (SOD) is an important antioxidant defense for cells exposed to oxygen. SOD converts superoxide into less toxic substances such as hydrogen peroxide and oxygen.
SOD + (Superoxide) -> H2O2 (Hydrogen Peroxide) + O2 (Oxygen)

The enzymes catalase and glutathione peroxidase are responsible for transforming hydrogen peroxide into oxygen and water. The water formed interferes with the production of cellular energy (transfer of electrons through the mitochondria). The action of the enzymes catalase and glutathione peroxidase would be a step that could be avoided if it were possible to adopt a strategy that does not produce superoxides (free radicals), mainly through diet. Without a doubt, the SOD enzyme complex is one of the most efficient in the body, and this is enough to ensure continued stability in the health/longevity process and quality of life.

Researchers have demonstrated that cancer cells can be deactivated by these enzymes. There are several forms of the SOD enzyme. Like all enzymes, they are proteins with a reactive center (which will interact with other substances) which can be copper, zinc, manganese, iron, or nickel. Several health problems have been related to the deficiency or inactivation of the superoxide dismutase enzyme, one of which concerns people is the loss of body mass and aging that is refractory to any nutritional regime that aims to gain weight through diet. Virtually the cytoplasm of all eukaryotic cells contains copper and zinc SOD (Cu-Zn-SOD) enzymes. Copper and zinc SOD are dimers with a molecular weight of 32,500 daltons. The two subunits of this dimer are joined by hydrophobic and electrostatic reactions. Histidine (an amino acid) binds to copper or side zinc.

Most bacteria contain the manganese form of the enzyme, which is the same form found in the mitochondria of human cells. In this case, the manganese ion is linked to three side chains of histidine, one of aspartate, and one of water or hydroxyl. E. coli bacteria and many other bacteria also contain the form of the enzyme with iron in its active center (Fe-SOD). Others contain manganese (Mn-SOD); in some, there are both. The active sites of the Mn and Fe superoxide dismutase enzymes contain the same type of amino acid side chains (histidine).

Recalling that superoxide dismutase is a class of closely related enzymes that catalyze the transformation of superoxide anion into oxygen and hydrogen peroxide (H2O2). These enzymes are present in almost all cells and in extracellular fluids. Superoxide dismutase enzymes are enzymes that contain in their structure metals that can be copper, zinc, manganese, or iron in addition to nickel. In humans, copper and zinc superoxide dismutase are present in the cytoplasm, while manganese superoxide dismutase is present in the mitochondria. A third form also exists in extracellular fluids. Mitochondrial superoxide dismutase is the most biologically important of these three, and the lack of this causes death soon after birth, unlike the lack of enzymes (SOD) with the active nucleus of copper or zinc or something other than manganese.

Our enzymatic capacity begins to decline around the age of 40 due to previously adopted habits, and in any case, this condition was caused by some attitude taken in the past related to food. If we consider the amount of superoxide dismutase enzyme we have right after birth, at least theoretically our life expectancy should be 135 years of age. However, around the age of forty, the amount of superoxide dismutase enzyme is reduced by half due to oxidative stress caused by a diet that produces free radicals.

The brain is particularly vulnerable to oxidative damage due to its high need for oxygen, unlike other organs. Consequently, antioxidants are commonly used as medication to treat various forms of brain damage. The enzyme superoxide dismutase mimics, without side effects, the sodium barbiturate thiopental and the experimental drug NXY-059 that are used to treat traumatic brain damage. These compounds appear to prevent oxidative stress in neurons and prevent apoptosis (programmed cell suicide) and neurological damage, just as the dismutase enzymes do naturally. Superoxide dismutase enzymes are also being investigated for possible treatments of neurodegenerative diseases like Alzheimer's and Parkinson's disease. Superoxide is the most important reactive oxygen species, and the SOD enzyme is its natural antioxidant.

The lack or inactivation of the enzyme (SOD2 and SOD3) is related to several human diseases. SODs are used in cosmetic products to reduce the effects of skin damage caused by radiation in breast cancer patients due to their property in reducing fibrosis (scarring).

Manganese

Manganese is the element responsible for the functioning of the enzyme superoxide dismutase 2 (SOD2), which is found in the mitochondria, as it is in the active center of this enzyme. Manganese deficiency in the body causes several disorders, some of them extremely serious, such as skeletal malformations, and others such as dermatitis, arthritis, Parkinson's disease, osteoporosis, schizophrenia, and diabetes. Without the enzyme SOD2 or SODmn, biological life is not possible. Newborns lacking MnSOD die soon after birth. By the way, SOD manganese is found in leafy vegetables, nuts, whole grains, and fruits.