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Enzymes

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Description	Biochem/physiol Actions	Product #
Catalase from bovine liver aqueous suspension, 40,000-60,000 units/mg protein (E1%/405)	Activates the decomposition of hydrogen peroxide, Natural antioxidant used to study roles of reactive oxygen species in gene expression and apoptosis.	C100
Catalase from bovine liver aqueous solution, ≥40,000 units/mg protein (E1%/405)	Activates the decomposition of hydrogen peroxide, Natural antioxidant used to study roles of reactive oxygen species in gene expression and apoptosis.	C3155
Glutathione Peroxidase from human erythrocytes lyophilized powder, >30 units/mg protein		G4013
Glutathione Peroxidase from bovine erythrocytes lyophilized powder, 300-700 units/mg protein		G6137
O⁶-Methlyguanine-DNA Methyltransferase human ≥90% (SDS-PAGE), recombinant, expressed in Escherichia coli, buffered aqueous glycerol solution, ≥10,000 units/mg protein	O⁶-Methylguanine-DNA methyl transferase (MGMT), containing 207 amino acids, is a ubiquitous DNA repair enzyme that removes O⁶-alkyl-guanine, primarily O⁶-methylguanine, lesions from damaged DNA. O⁶-Methylguanine-DNA methyl transferase (MGMT), containing 207 amino acids, is a ubiquitous DNA repair enzyme that removes O⁶-alkyl-guanine, primarily O⁶-methylguanine, lesions from damaged DNA. It is a major contributor to cellular protection from the mutagenic, carcinogenic, and cytotoxic effects of DNA alkylation. Its action is based on the transfer of the alkyl group from the DNA to a unique acceptor cysteine residue in the protein, forming a stable thioether linkage. The cysteine sulfhydryl moiety is not regenerated and therefore, MGMT is frequently classified as a suicide enzyme. Since the reactionirreversibly inactivates the enzyme, the repair capacity for O⁶-methylguanine is dependent on the number of MGMT molecules in the cell. There is a correlation between the occurrence of cancer in various tissues and the lack of the MGMT enzyme. High levels of MGMT result in reduced tumor events and resistance of tumors to alkylating agents.	M8065
Myeloperoxidase from human leukocytes lyophilized powder, ≥50 units/mg protein	Catalyzes oxidations by hydrogen peroxide, including cytotoxic actions on bacteria, fungi, and tumor cells. Also catalyzes cross-linking of immune complexes and inactivates chemotactic factors.	M6908
Nitrate Reductase (cytochrome) from Escherichia coli lyophilized powder, ≥5 units/g solid		N0519
Peroxidase from horseradish Type VI, essentially salt-free, lyophilized powder, 250-330 units/mg solid (using pyrogallol)		P8375
Peroxidase from horseradish Type VI-A, essentially salt-free, lyophilized powder, ~1000 units/mg solid (using ABTS), 250-330 units/mg solid (using pyrogallol)		P6782
Peroxiredoxin 1 human ≥85% (SDS-PAGE), recombinant, expressed in Escherichia coli, lyophilized powder	Peroxiredoxins are a novel defined family of peroxidases of approximately 25 kDa that reduce H₂O₂ and alkyl hydroperoxides and use mainly the thioredoxin (Trx) system (Trx, thioredoxin reductase and NADPH) as electron donor. The peroxiredoxin family includes more than 30 proteins from organisms of all kingdoms. Peroxiredoxin I belongs to the Type I Peroxiredoxin family. This family consists of human natural killer cell enhancing factor (NKEFA), human proliferation associated gene (PAG), mouse macrophage stress induced protein (MSP23), mouse osteoblast specific factor (OSF-3), and rat heme-binding protein (HBP23). These proteins share about 95% homology.	P8986
Superoxide Dismutase from bovine erythrocytes lyophilized powder, 2,500-7,000 units/mg protein	Catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. Plays a critical role in the defense of cells against the toxic effects of oxygen radicals. Competes with nitric oxide (NO) for superoxide anion (which reacts with NO to form peroxynitrite), thereby SOD promotes the activity of NO.¹ SOD has also been shown to suppress apoptosis in cultured rat ovarian follicles, neural cell lines, and transgenic mice.^2,³	S2515
Superoxide Dismutase from human erythrocytes lyophilized powder, 2,500-6,000 units/mg protein	Catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. Plays a critical role in the defense of cells against the toxic effects of oxygen radicals. Competes with nitric oxide (NO) for superoxide anion (which reacts with NO to form peroxynitrite), thereby SOD promotes the activity of NO.¹ SOD has also been shown to suppress apoptosis in cultured rat ovarian follicles, neural cell lines, and transgenic mice.^2,³	S9636
Superoxide Dismutase from bovine erythrocytes 2,500-7,000 units/mg protein, lyophilized powder, cell culture tested	Catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. Plays a critical role in the defense of cells against the toxic effects of oxygen radicals. Competes with nitric oxide (NO) for superoxide anion (which reacts with NO to form peroxynitrite), thereby SOD promotes the activity of NO.¹ SOD has also been shown to suppress apoptosis in cultured rat ovarian follicles, neural cell lines, and transgenic mice.^2,³	S5395
Thioredoxin Reductase from rat liver buffered aqueous glycerol solution	Thioredoxin reductase (TrxR) is an NADPH-dependent oxidoreductase containing one FAD per subunit that reduces the active site disulfide in oxidised thioredoxin (Trx). The molecular weight of the isozymes from mammalian sources vary between 55-67 kDa as compared with 35 kDa in prokaryotes, plants or yeast. The substrate specificity of the mammalian enzyme is much broader than the prokaryotic enzyme reducing both mammalian and E. coli thioredoxins as well as well as non-disulfide substrates such selenite, lipoic acids, lipid hydroperoxides and hydrogen peroxide. Thioredoxin reductase from mammalian sources contains a selenocysteine residue that is essential for the activity of the enzyme. It is one of the antioxidant enzymes present in the mammalian cell together with catalase, glutathione peroxidase and superoxide dismutase, and helps in removal of reactive oxygen species (ROS) from the cell. An example is the removal of excess nitric oxide (NO) by the formation of a complex with glutathione forming the S-nitroso-glutathione adduct (GS-NO). This can be cleaved directly by thioredoxin reductase. Hydrogen peroxide, another deleterious oxidant in the cell, is also reduced directly by mammalian TrxR.	T9698
Thioredoxin Reductase from Escherichia coli ammonium sulfate suspension, >25 units/mg protein (Bradford)	An FAD-containing enzyme involved in the transfer of hydrogen from E. coli thioredoxin to other proteins thus providing a powerful disulfide reductase system. Thioredoxin reductase (TrxR) is an NADPH-dependent oxidoreductase containing one FAD per subunit that reduces the active site disulfide in oxidised thioredoxin (Trx). The molecular weight of the isozymes from mammalian sources vary between 55-67 kDa as compared with 35 kDa in prokaryotes, plants or yeast. The substrate specificity of the mammalian enzyme is much broader than the prokaryotic enzyme reducing both mammalian and E. coli thioredoxins as well as well as non-disulfide substrates such selenite, lipoic acids, lipid hydroperoxides and hydrogen peroxide.	T7915

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