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oxidative stress: the importance of glutathione S-transferase and glutathione peroxidase activities in auxin heterotrophic and autotrophic calli . J. Plant Physiol. 161 , 691 – 699 . 2
redox states of ascorbate and glutathione in wheat leaves . Acta Physiol. Plant. 37 : 200 . Dalton , D.A. , Russell , S.A. , Hanus , F.J. , Pascoe , G.A. , Evans , H
Abou Ghalia, A. H., Fouad, I. M. (2000) Glutathione and its metabolizing enzymes in patients with different benign and malignant diseases. Clin. Biochem. 33 , 657
Igarashi, T., Satoh, T., Ueno, K., Kitagawa, H. (1983) Species differences in glutathione level and glutathione related enzyme activities in rats, mice, guinea pigs, and hamsters. J. Pharmacobiodyn. 6, 941. Species differences in
., Wurm, W. H., Greenblatt, D. J. (1997) Differential effect of central versus parenteral administration of morphine sulfate on regional concentrations of reduced glutathione in rat brain. Pharmacology 54 , 92
In recent years, the importance of the endogenous plant tripeptide glutathione (GSH) has been increasingly recognized in plant-pathogen interactions due to its contribution to various signaling and defense mechanisms. In this paper the recent developments in the research for possible roles of GSH in infected plants are summarized. GSH participates not only in antioxidative and detoxification reactions but also in redox regulation of the expression of protective genes in infected cells. Several lines of evidence suggest that glutathione S-transferase (GST) isoenzymes also have an important role in plant disease resistance, but their exact functions have remained elusive.
Yeast protein sequence-based homology search for glutathione (GSH) metabolic enzymes and GSH transporters demonstrated that Aspergillus nidulans has a robust GSH uptake and metabolic system with several paralogous genes. In wet laboratory experiments, two key genes of GSH metabolism, gcsA, and glrA, encoding γ-l-glutamyl-l-cysteine synthetase and glutathione reductase, respectively, were deleted. The gene gcsA was essential, and the ΔgcsA mutant required GSH supplementation at considerably higher concentration than the Saccharomyces cerevisiae gsh1 mutant (8–10 mmol l−1 vs. 0.5 μmol l−1). In addition to some functions known previously, both genes were important in the germination of conidiospores, and both gene deletion strains required the addition of extra GSH to reach wild-type germination rates in liquid cultures. Nevertheless, the supplementation of cultures with 10 mmol l−1 GSH was toxic for the control and ΔglrA strains especially during vegetative growth, which should be considered in future development of high GSH-producer fungal strains. Importantly, the ΔglrA strain was characterized by increased sensitivity toward a wide spectrum of osmotic, cell wall integrity and antimycotic stress conditions in addition to previously reported temperature and oxidative stress sensitivities. These novel phenotypes underline the distinguished functions of GSH and GSH metabolic enzymes in the stress responses of fungi.
Abstract
Lead(II) complexes of reduced glutathione (GSH) of general composition [Pb(L)(X)]H2O (where L=GSH; X=Cl, NO3, CH3COO, NCS) have been synthesized and characterized by elemental analyses, infrared spectra and electronic spectra. Thermogravimetric (TG) and differential thermal analytical (DTA) studies have been carried out for these complexes. Infrared spectra indicate deprotonation and coordination of cysteinyl sulphur with metal ion. It indicates the presence of water molecule in the complexes that has been supported by TG/DTA. The thermal behaviour of complexes shows that water molecule is removed in first step-followed removal of anions and then decomposition of the ligand molecule in the subsequent steps. Thermal decomposition of all the complexes proceeds via first order kinetics. The thermodynamic activation parameters, such as E*, A, ΔH*, ΔS* and ΔG* have been calculated. The geometry of the metal complexes has been studied with the help of molecular modeling for energy minimization calculation.
To study the possible effects of different inclusion levels of distillers dried grain with solubles (DDGS) on the lipid peroxidation and glutathione redox status of chickens, 200 three-week-old Ross 308 cockerels were assigned to four treatment groups of 50 birds each. The groups were fed a control and three experimental, isocaloric and isonitrogenous grower diets containing 15, 20 and 25% DDGS, respectively, combined with lysine (Lys) and methionine (Met) supplementation until 6 weeks of age. It was found that DDGS inclusion increased the ether extract content of the diets which resulted in higher reduced glutathione (GSH) content and elevated glutathione peroxidase activity (GSHPx) in the liver. However, DDGS addition with Lys and Met supplementation did not influence the malondialdehyde content of the blood and the liver. The oleic acid proportion of the diet showed a close positive correlation with GSH content of the liver. A smaller ratio of methionine and cysteine in the diet with DDGS resulted in significantly higher liver GSH content. GSHPx activity increased parallel with the elevated GSH content of the liver homogenate, suggesting that the enzyme is activated by the actual supply of its co-substrate. In conclusion, the results show that DDGS, even at a high inclusion level combined with Lys and Met supplementation, has no initiative effect on lipid peroxidation in the blood and liver of broiler chickens.
References 1. Adamis , P. D. , Mannarino , S. C. , Eleutherio , E. C. ( 2009 ) Glutathione and gamma-glutamyl transferases are involved in the formation of
