Biomaterial Database

The reduction of dithiobis(2-nitrobenzoate) by rat liver mitochondria. 1986

P C Jocelyn, and A D Cronshaw

5,5'-Dithiobis(2-nitrobenzoate) (DTNB) is reduced in mitochondrial suspensions to 5-mercapto-2-nitrobenzoate (MNB) by 3-hydroxybutyrate and isocitrate. Although most of the MNB produced is found in the suspension medium, there is also some within the particles. The amount of MNB found in these fraction varies with the DTNB concentration used and is much lower if mitochondrial glutathione (GSH) is depleted with 1-chloro-2,4-dinitrobenzene. If hydroxybutyrate is present, the reduction of DTNB is increased by ATP and oligomycin. The pellet contains only a little MNB and GSH but these are considerably elevated by antimycin and rotenone as well as by ATP and oligomycin. If isocitrate is present, the reduction of DTNB is greatly stimulated by valinomycin, triethyltin and, to a lesser extent, oligomycin. MNB in the pellet falls and GSH concentrations are unchanged. The results suggest that with hydroxybutyrate (an NAD reducing substrate), the rate of reduction of DTNB is limited by the rate of regeneration of GSH while with isocitrate (an NADP reducing substrate) it is limited by the rate of export of MNB from the matrix.

UI	MeSH Term	Description	Entries
D007523	Isocitrates	Derivatives of isocitric acid, a structural isomer of CITRIC ACID, including its salts and esters.
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D009579	Nitrobenzoates	Benzoic acid or benzoic acid esters substituted with one or more nitro groups.	Nitrobenzoic Acids,Acids, Nitrobenzoic
D009840	Oligomycins	A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).	Oligomycin
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
D010416	Pentachlorophenol	An insecticide and herbicide that has also been used as a wood preservative. Pentachlorphenol is a widespread environmental pollutant. Both chronic and acute pentachlorophenol poisoning are medical concerns. The range of its biological actions is still being actively explored, but it is clearly a potent enzyme inhibitor and has been used as such as an experimental tool.	Sodium Pentachlorophenate,Pentachlorophenate, Sodium
D004137	Dinitrochlorobenzene	A skin irritant that may cause dermatitis of both primary and allergic types. Contact sensitization with DNCB has been used as a measure of cellular immunity. DNCB is also used as a reagent for the detection and determination of pyridine compounds.	1-Chloro-2,4-Dinitrobenzene,2,4-Dinitrochlorobenzene,Benzene, 1-Chloro-2,4-Dinitro-,Chlorodinitrobenzene,DNCB,1 Chloro 2,4 Dinitrobenzene,2,4 Dinitrochlorobenzene
D004228	Dithionitrobenzoic Acid	A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.	5,5'-Dithiobis(2-nitrobenzoic Acid),DTNB,Ellman's Reagent,5,5'-Dithiobis(nitrobenzoate),Acid, Dithionitrobenzoic,Ellman Reagent,Ellmans Reagent,Reagent, Ellman's
D005978	Glutathione	A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.	Reduced Glutathione,gamma-L-Glu-L-Cys-Gly,gamma-L-Glutamyl-L-Cysteinylglycine,Glutathione, Reduced,gamma L Glu L Cys Gly,gamma L Glutamyl L Cysteinylglycine
D006885	Hydroxybutyrates	Salts and esters of hydroxybutyric acid.	Hydroxybutyric Acid Derivatives,Hydroxybutyric Acids,Acid Derivatives, Hydroxybutyric