scholarly journals Effects of linoleic acid hydroperoxide on the formation of lipid peroxide in rat liver mitochondria

1975 ◽  
Vol 71 (4) ◽  
pp. 317-322
Author(s):  
Tadashi FUJITA ◽  
Masahide YASUDA ◽  
Kenichi MATSUMOTO
Keyword(s):  
Linoleic Acid ◽  
Rat Liver ◽  
Lipid Peroxide ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Linoleic Acid Hydroperoxide ◽  
Acid Hydroperoxide

Intracellular mechanisms for the decomposition of a lipid peroxide. II. Decomposition of a lipid peroxide by subcellular fractions

1969 ◽  
Vol 47 (5) ◽  
pp. 493-499 ◽  
Author(s):  
P. J. O'Brien ◽  
C. Little
Keyword(s):  
Linoleic Acid ◽  
Glutathione Peroxidase ◽  
Ph Dependence ◽  
Lipid Peroxide ◽  
Subcellular Fractions ◽  
Radical Mechanism ◽  
Complexing Agents ◽  
Linoleic Acid Hydroperoxide ◽  
Hydrogen Donors ◽  
Acid Hydroperoxide

The properties of subcellular fractions of rat liver in catalyzing the decomposition of linoleic acid hydroperoxide have been compared with those of transition salts, heme compounds, and nucleophiles. The properties compared included the range of products produced, the pH dependence of the reaction, and the effects of metal-complexing agents, inhibitors, and hydrogen donors. It was concluded that the decomposition of the hydroperoxide in the liver cell was due principally to reaction with the intracellular nucleophile glutathione by a mechanism catalyzed by the enzyme glutathione peroxidase. In the absence of glutathione, however, both the mitochondrial and microsomal fractions decomposed the hydroperoxide presumably by a radical mechanism probably involving the cytochromes.

scholarly journals A novel glutathione transferase (13–13) isolated from the matrix of rat liver mitochondria having structural similarity to class theta enzymes

1991 ◽  
Vol 278 (1) ◽  
pp. 137-141 ◽  
Author(s):  
J M Harris ◽  
D J Meyer ◽  
B Coles ◽  
B Ketterer
Keyword(s):  
Rat Liver ◽  
Glutathione Transferase ◽  
Ethacrynic Acid ◽  
Gel Filtration ◽  
Cumene Hydroperoxide ◽  
Structural Similarity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Linoleic Acid Hydroperoxide ◽  
The Matrix

A rat liver mitochondrial-matrix fraction was prepared and shown to have 1-chloro-2,4-dinitrobenzene(CDNB)-metabolizing glutathione transferase (GST) activity. Further fractionation by sequential gel filtration, isoelectric focusing or chromatofocusing and hydroxyapatite chromatography yielded three GSTs of pI 9.3, 8.9 and 7.5, none of which bound to a GSH-agarose affinity matrix. Most of the activity was associated with the pI-9.3 form, which was selected for further study. Its activity was tested with the following potential substrates in addition to CDNB: 1,2-dichloro-4-nitrobenzene, p-nitrobenzyl chloride, trans-4-phenylbut-3-en-2-one, 1,2-epoxy-3-(p-nitrophenoxy)propane, ethacrynic acid, menaphthyl sulphate, cumene hydroperoxide, linoleic acid hydroperoxide and 4-hydroxynon-2-enal. Appreciable activity was obtained only with CDNB and ethacrynic acid (82 and 26 mumol/min per mg of protein respectively). The apparent Km for GSH, using 1 mM-CDNB, was 1.9 mM. The enzyme is a dimer of subunit Mr 26,500. It has a free N-terminus, which has enabled the first 33 amino acids to be sequenced. This portion of primary structure has a sequence in common with members of the Theta class of GSTs (eg. 36% identity with subunit 12) and also a sequence which might function as a mitochondrial import signal. It is novel and has been named ‘GST 13-13’.

Selenium-independent glutathione peroxidase activity in rabbit liver

1980 ◽  
Vol 58 (10) ◽  
pp. 1012-1017 ◽  
Author(s):  
Paul Morrissey ◽  
Peter J. O'Brien
Keyword(s):  
Linoleic Acid ◽  
Glutathione Peroxidase ◽  
Glutathione Transferase ◽  
Lipid Peroxide ◽  
Rabbit Liver ◽  
Linoleic Acid Hydroperoxide ◽  
Glutathione Peroxidase Activity ◽  
Liver Cytosol ◽  
Acid Hydroperoxide ◽  
Rat Liver Cytosol

The reduction of linoleic acid hydroperoxide catalyzed by rat liver cytosol was previously shown to be catalyzed by a selenium-dependent glutathione peroxidase. In contrast, the activity in rabbit liver cytosol could also be attributed to a selenium-independent glutathione peroxidase present in an approximately equal amount to the selenium-dependent peroxidase. The selenium-independent peroxidase copurified with glutathione transferase B and was completely inhibited by antitransferase B antiserum and transferase substrates. These results suggest that glutathione transferase B in rabbit liver cytosol is involved in the intracellular decomposition of lipid peroxide and could explain the lower selenium requirement of rabbits in comparison with other species.

Intracellular mechanisms for the decomposition of a lipid peroxide. I. Decomposition of a lipid peroxide by metal ions, heme compounds, and nucleophiles

1969 ◽  
Vol 47 (5) ◽  
pp. 485-492 ◽  
Author(s):  
P. J. O'Brien
Keyword(s):  
Catalytic Activity ◽  
Linoleic Acid ◽  
Metal Ions ◽  
Ph Dependence ◽  
Lipid Peroxide ◽  
Transition Metal Ions ◽  
Complexing Agents ◽  
Linoleic Acid Hydroperoxide ◽  
Hydrogen Donors ◽  
Acid Hydroperoxide

Linoleic acid hydroperoxide was prepared. Two types of mechanisms for its decomposition were found. The hydroperoxide was rapidly decomposed by certain transition metal ions, heme, and hemoprotein to a complex range of products, the decomposition being accompanied by changes in ultraviolet absorption spectra. The production of radical oxidizing species may account for these products. It was also found that the hydroperoxide could be decomposed by nucleophiles presumably in a nonradical reaction to a hydroxy acid without any change in ultraviolet spectra.The kinetics, the pH dependence, and the effects of metal-complexing agents, inhibitors, and hydrogen donors on the catalytic activity of the metal ions and heme compounds were also investigated.

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