Superoxide Dismutase bovine recombinant, expressed in E. coli, lyophilized powder, =2500 units/mg protein, =90% (SDS-PAGE)

Synonym: CU/ZN-SOD, SOD1, SOD, Superoxide Dismutase 1 bovine, Superoxide: superoxide oxidoreductase

CAS Number: 9054-89-1

EC Number: 232-943-0

Enzyme Commission (EC) Number: 1.15.1.1

MDL Number: MFCD00132404

Analysis Note
Extinction coefficient: E^mM= 10.3 (258 nM) SOD has no significant absorbance peak at 280 nM because of the absence of tryptophan.

Other Notes
Inhibitors: cyanide, OH^- (competitive), hydrogen peroxide

Preparation Note
Produced using animal component-free materials.

Reconstitution
Reconstitute in 10 mM KPO₄, pH 7.4.

Unit Definition
One unit will inhibit reduction of cytochrome c by 50% in a coupled system with xanthine oxidase at pH 7.8 at 25°C in a 3.0 ml reaction volume. Xanthine oxidase concentration should produce an initial ?A550 of 0.025 ± 0.005 per min.

Application
Superoxide dismutase has been used in a study to investigate where lipoproteins may affect the L-arginine-nitric oxide pathway. Superoxide dismutase has also been used in a study to investigate the mass spectral evidence for carbonate-anion-radical-induced posttranslational modification of tryptophan to kynurenine in human Cu, Zn superoxide dismutase.

The product has been used to develop an SOD assay. This assay used dismutase-mediated inhibition of NADH-dependent nitroblue tetrazolium reduction.

Biochem/physiol Actions
Superoxide dismutase (SOD) catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. SOD plays a critical role in the defense of cells against the toxic effects of oxygen radicals. SOD competes with nitric oxide (NO) for superoxide anion (which reacts with NO to form peroxynitrite), thereby SOD promotes the activity of NO. SOD has also been shown to suppress apoptosis in cultured rat ovarian follicles, neural cell lines, and transgenic mice by preventing the conversion of NO to peroxynitrate, an inducer of apoptosis.

General Description
SOD from bovine erythrocytes was the first SOD to be found in mammalian tissues. Before its enzymatic activity was discovered the protein was known as haemocuprein or erythrocuprein. SOD from bovine erythrocytes is a homodimeric non-covalently bound protein with two 16.3 kDa subunits of 151 amino acids. Each monomer has one intrachain disulfide and one free sulfhydryl, one Cu⁺² atoms and one Zn⁺² atoms. There are three forms of SOD differentiated by the metal ions in the active site. These are Cu⁺²/Zn⁺², Mn⁺², and Fe⁺² SOD. In vertebrate organisms Cu/Zn-SOD is found in the cytoplasm and the mitochondrial intermembrane space, while Mn-SOD is found in the mitochondrial matrix space. Fe-SOD is found in prokaryotes and some higher plants.