SOD catalyzes the conversion of superoxide radicals to O2 and H2O2, while CAT, POD and APX catalyze dismutation reactions of H2O2 into H2O (Mittler 2002).
It was well known that Fe2+ can alternately catalyze dismutation of the hydrogen peroxide (H2O2) into other reactive hydroxyl radical according to Fenton reaction [31].
Extracellular superoxide dismutase (ecSOD, SOD3) is the major SOD in the vascular extracellular space that catalyzes dismutation of superoxide anion (O2−) to H2O2 [14].
The superoxide dismutase protects organisms against oxygen toxicity by catalyzing dismutation of the reactive radical to hydrogen peroxide and oxygen.
SOD is an important antioxidant enzyme that can decrease the destruction of the superoxide radical by catalyzing dismutation and H2O2 formation.
Catalase and GSHPx catalyze dismutation of the superoxide anion (O2-) into hydrogen peroxide (H2O2) which then converting H2O2 to water thus providing protection against ROS [ 28].
It is the primary antioxidant enzyme that protects cells from oxidative stress by catalyzing dismutation of superoxide to hydrogen peroxide and oxygen in the mitochondria of eukaryotic cells.
SOD (including 3 forms: cytosolic - SOD1, mitochondrial - SOD2 and extracellular - SOD3) catalyze dismutation of superoxide anion into hydrogen peroxide, whereas Cat and GPxs reduce hydrogen peroxide, thus preventing production of highly toxic hydroxyl radical [ 13].
The SOD activity of the complex has been evaluated by the nitro blue tetrazolium assay and the complex catalyzed the dismutation of superoxide at pH 7.8 with an IC50 value of 0.36 μmol dm−3.
SOD is an important component of the antioxidant defense system in plants and catalyzes dismutation of superoxide into oxygen and hydrogen peroxide.
ecSOD is the enzyme that catalyzes dismutation of O2− to produce H2O2 in the extracellular space by anchoring to ECs surface or extracellular matrix through HBD [14].
