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Selenium independent glutathione peroxidase activity associated with cationic forms of glutathione transferase in human heart
- Source :
- Journal of Molecular and Cellular Cardiology. 18:983-991
- Publication Year :
- 1986
- Publisher :
- Elsevier BV, 1986.
-
Abstract
- Glutathione peroxidase activity with both hydrogen peroxide and cumene hydroperoxide was measured in the cytosolic fractions prepared from five human hearts obtained from post-mortem victims. In all the samples the activity with cumene hydroperoxide was higher than that obtained with hydrogen peroxide, suggesting that the selenium-independent glutathione peroxidase could also be present in this tissue. To determine its presence in heart tissue we fractionated the cardiac cytosol fraction on a column of Sephadex G-100 and measured glutathione peroxidase activity with both the substrates. Glutathione transferase activity was measured with 1-chloro-2,4-dinitrobenzene in the fractionated cytosol. The results indicated that a selenium-independent glutathione peroxidase activity was present (about 30% of total activity). Fractionation of the cytosol by gel filtration showed that peroxidase activity co-eluted with glutathione transferase activity. Subsequently the fractions containing glutathione transferase and selenium-independent glutathione peroxidase activity obtained from gel filtration experiments were passed through an affinity column and analyzed by isoelectric focusing. It was found that the selenium-independent glutathione peroxidase copurified with three isoenzymes of glutathione transferase which had a pI of 9.2, 8.9 and 8.6 respectively. In contrast the acidic isoenzymes of glutathione transferase lacked peroxidase activity. It is suggested that the selenium-independent glutathione peroxidase may play an important role in neutralizing oxygen toxicity in heart when the selenium-dependent glutathione peroxidase activity is impaired.
- Subjects :
- GPX1
GPX3
Glutathione reductase
GPX4
Chromatography, Affinity
GPX6
Substrate Specificity
Selenium
Cytosol
Humans
Settore BIO/10
Glutathione transferase activity
Molecular Biology
Glutathione Transferase
chemistry.chemical_classification
Chromatography
Glutathione Peroxidase
biology
Chemistry
Myocardium
Glutathione peroxidase
Liver
Isoenzymes
Isoelectric Focusing
Affinity
Biochemistry
biology.protein
Cardiology and Cardiovascular Medicine
Peroxidase
Subjects
Details
- ISSN :
- 00222828
- Volume :
- 18
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular and Cellular Cardiology
- Accession number :
- edsair.doi.dedup.....df41f50546e05ac7b7bce8e83fcb5d1c