Biomaterial Database

Microplate superoxide dismutase assay employing a nonenzymatic superoxide generator. 1995

J F Ewing, and D R Janero

NitroMed, Inc., NitroMed Research Laboratories, Boston, Massachusetts 02118, USA.

The antioxidant enzyme superoxide dismutase (EC 1.15.1.1) (SOD) catalyzes the conversion of superoxide anion radical (O2.-) to hydrogen peroxide and molecular oxygen. SOD helps prevent tissue damage by O2.- and its metabolites, and augmentation of tissue SOD is a useful therapeutic strategy in certain diseases having an oxidative-injury component. Routine application of direct SOD assays is not technically facile, since the short half-life of the O2.- substrate and its free radical nature necessitate specialized analytical equipment to detect and measure O2.- chemically. Consequently, indirect SOD assays which monitor some change in an indicator substance reacting with O2.- are routinely used, particularly for biological samples. Limitations of indirect test systems utilizing heme-based indicators for the presence of O2.- and/or enzymatic O2.- generators led us to develop a SOD microassay based on spectrophotometric assessment of O2.- mediated nitro blue tetrazolium reduction by an aerobic mixture of NADH and phenazine methosulfate, which produces superoxide chemically at nonacidic pH (Rao, Free Radical Biol. Med. 7, 513-519, 1989). The proposed SOD assay system is formatted for use in an automated 96-well microplate reader and has the virtues of a nonheme indicator, a nonenzymatic O2.- source, physiological pH, and economy of time and materials. The assay has been applied to measure purified and tissue SOD (Cu,Zn- and Mn-types) activity as well as O2.- turnover by small-molecule "SOD mimetics."

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D008175	Lung Neoplasms	Tumors or cancer of the LUNG.	Cancer of Lung,Lung Cancer,Pulmonary Cancer,Pulmonary Neoplasms,Cancer of the Lung,Neoplasms, Lung,Neoplasms, Pulmonary,Cancer, Lung,Cancer, Pulmonary,Cancers, Lung,Cancers, Pulmonary,Lung Cancers,Lung Neoplasm,Neoplasm, Lung,Neoplasm, Pulmonary,Pulmonary Cancers,Pulmonary Neoplasm
D008297	Male		Males
D008773	Methylphenazonium Methosulfate	Used as an electron carrier in place of the flavine enzyme of Warburg in the hexosemonophosphate system and also in the preparation of SUCCINIC DEHYDROGENASE.	Phenazine Methosulfate,5-Methylphenazinium Methyl Sulfate,5 Methylphenazinium Methyl Sulfate,Methosulfate, Methylphenazonium,Methosulfate, Phenazine,Methyl Sulfate, 5-Methylphenazinium,Sulfate, 5-Methylphenazinium Methyl
D008832	Microchemistry	The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D009363	Neoplasm Proteins	Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.	Proteins, Neoplasm
D009580	Nitroblue Tetrazolium	Colorless to yellow dye that is reducible to blue or black formazan crystals by certain cells; formerly used to distinguish between nonbacterial and bacterial diseases, the latter causing neutrophils to reduce the dye; used to confirm diagnosis of chronic granulomatous disease.	Nitro-BT,Nitrotetrazolium Blue,Tetrazolium Nitroblue,Blue, Nitrotetrazolium,Nitroblue, Tetrazolium,Tetrazolium, Nitroblue
D009928	Organ Specificity	Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.	Tissue Specificity,Organ Specificities,Specificities, Organ,Specificities, Tissue,Specificity, Organ,Specificity, Tissue,Tissue Specificities
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction