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1
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Overexpression of genes involved in phytochelatin biosynthesis in Escherichia coli: effects on growth, cadmium accumulation and thiol level.

100%
Wawrzyńska A., Wawrzyński A., Gaganidze D., Kopera E., Piątek K., Bal W., Sirko A.
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2005
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vol. 52
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issue 1
109-116
EN
In Escherichia coli, heterologous production of Schizosaccharomyces pombe phytochelatin synthase (PCS) along with overproduction of E. coli serine acetyltransferase (SAT) and γ-glutamylcysteine synthase (γECS) was achieved and resulted in the accumulation of phytochelatins in bacterial cells. Overproduction of either γECS alone or simultaneous production of all three proteins in bacterial cells were accompanied by reduced growth rate in liquid cultures. Interestingly, bacteria overproducing either γECS or both SAT and γECS (with elevated level of γ-glutamylcysteine but not of phytochelatins) were able to accumulate more cadmium per dry weight than the control. However, the most efficient cadmium accumulation was observed in bacteria with elevated levels of all three proteins: SAT, γECS and PCS. Therefore, "pushing" the entire pathway might be the most promising approach in modification of bacteria for potential bioremediation purposes because the level of intermediates, cysteine and glutathione, can limit the rate of production of phytochelatins. However, in such bacteria other metabolic process might become limiting for efficient growth.
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In vitro inhibition of topoisomerase IIα by reduced glutathione

100%
Delwar Z., Vita M., Siden Å., Cruz M., Yakisich J.
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2011
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vol. 58
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issue 2
265-267
EN
In most cells, the major intracellular redox buffer is glutathione (GSH) and its disulfide-oxidized (GSSG) form. The GSH/GSSG system maintains the intracellular redox balance and the essential thiol status of proteins by thiol disulfide exchange. Topoisomerases are thiol proteins and are a target of thiol-reactive substances. In this study, the inhibitory effect of physiological concentration of GSH and GSSG on topoisomerase IIα activity in vitro was investigated. GSH (0-10 mM) inhibited topoisomerase IIα in a concentration-dependent manner while GSSG (1-100 µM) had no significant effect. These findings suggest that the GSH/GSSG system could have a potential in vivo role in regulating topoisomerase IIα activity.
3
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Transport of organic anions by multidrug resistance-associated protein in the erythrocyte.

88%
Rychlik B., Pułaski Ł., Sokal A., Soszyński M., Bartosz G.
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2000
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vol. 47
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issue 3
763-772
EN
The active transport of oxidized glutathione and glutathione S-conjugates has been demonstrated for the first time in erythrocytes and this cell remained the main subject of research on the "glutathione S-conjugate pump" for years. Further studies identified the "glutathione S-conjugate pump" as multidrug resistance-associated protein (MRP). Even though cells overexpressing MRP and isolated MRP provide useful information on MRP structure and function, the erythrocyte remains an interesting model cell for studies of MRP1 in its natural environment, including the substrate specificity and ATPase activity of the protein.
4
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The influence of single application of paracetamol and/or N-acetylcysteine on rats in subchronic exposition to trichloroethylene vapours. II. Effect on hepatic glutathione level

88%
Plewka D., Plewka A., Kowalówka-Zawieja J., Zielińska-Psuja B., Przystanowicz J.
Medycyna Środowiskowa - Environmental Medicine
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2012
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vol. 15
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issue 3
91-95
EN
Background: Feature of modern existing hazards both environmental and occupational is cumulative exposure often leading to unexpected response of the organism resulting, among other things, in interactions with cytochrome P450 system involved in biotransformation of trichloroethylene and paracetamol. Hepatotoxity of paracetamol is closely connected with hepatic glutathione level. „In therapy of acute paracetamol poisoning application of N-acetylcysteine as a factor, which protects GSH level in cells, is recommended.” Materials and method: Tests were performed on rats which were treated with trichloroethylene, paracetamol and/or N-acetylcysteine. In rat liver total level of glutathione was determined i.e. reduced and oxidized form. Results: Paracetamol just after completion of the exposure affected the glutathione level. Trichloroethylene throughout the period of observation stimulated growth of glutathione level in liver. N-acetylcysteine didn’t have any influence on the level of investigated tripeptyde. Conclusions: N-acetylcysteine removes negative effect of paracetamol especially when it’s applied with 2-hour delay. After exposure for trichloethylene immediate application of N-acetylcysteine caused noticeable lowering of glutathione level. Cumulative exposure for three xenobiotics had positive influence for glutathione level in rat liver.
PL
Wstęp: Cechą współcześnie występujących zagrożeń, zarówno środowiskowych jak i zawodowych jest narażenie łączne, wielokrotnie prowadzące do nieprzewidzianej odpowiedzi biologicznej organizmu, wynikającej między innymi z oddziaływań na układ cytochromu P450 biorący udział w biotransformacji trichloroetylenu i paracetamolu. Hepatotoksyczność paracetamolu jest między innymi ściśle związana z wątrobowym poziomem glutationu. W terapii zatruć ostrych paracetamolem zalecane jest podawanie N-acetylocysteiny jako czynnika ochraniającego poziom GSH w komórkach. Materiał i metody: Badania wykonano na szczurach, które traktowano trichloroetylenem, paracetamolem i/lub N-acetylocysteiną. W wątrobie szczura oznaczano poziom całkowity glutationu, tj. formę zredukowaną i utlenioną. Wyniki: Paracetamol tuż po zakończeniu ekspozycji negatywnie wpływał na poziom glutationu. Trichloroetylen przez cały czas obserwacji stymulował wzrost poziomu glutationu w wątrobie. N-acetylocysteina nie miała żadnego wpływu na poziom badanego tripeptydu. Wnioski: N-acetylocysteina usuwała negatywny wpływ paracetamolu, szczególnie wtedy, kiedy podano ją z 2-godzinnym opóźnieniem. Po narażeniu na trichloroetylen natychmiastowe podanie N-acetylocysteiny niosło za sobą wyraźnie obniżenie poziomu glutationu. Narażenie łączne na trzy oceniane ksenobiotyki.
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Depletion of intracellular glutathione and increased lipid peroxidation mediate cytotoxicity of hematite nanoparticles in MRC-5 cells

88%
Radu M., Munteanu M. C., Petrache S., Serban A. I., Dinu D., Hermenean A., Sima C., Dinischiotu A.
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2010
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vol. 57
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issue 3
355-360
EN
Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe2O3 nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 µg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72h. Exposure to α-Fe2O3 nanoparticles increased lipid peroxidation by 81%, 189% and 110% after 24, 48 and 72h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2% and 51.4% after 48 and 72h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.
6
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Potentiometric determination of cysteine with thiol sensitive silver-mercury electrode

88%
Drożdż R., Naskalski J., Ząbek-Adamska A.
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2007
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vol. 54
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issue 1
205-211
EN
A potentiometric procedure for cysteine thiol group concentration monitoring in media generating free radicals was developed using a thiol specific silver-mercury electrode. Electrolytic deposition of mercury on a silver wire and treatment with 20 mM cysteine in 0.5 M NaOH were used to produce the electrode. A silver-chloride electrode in saturated KCl was the reference. A glass capillary with 1 M KNO3 in 1% agarose gel was the liquid junction. The electrode responded to cysteine concentration in the range from 0.01 to 20 mM yielding a perfect linear relationship for the dependence of log [cysteine] versus electrode potential [mV], with b0 (constant) = -373.43 [mV], b1 (slope) = -53.82 and correlation coefficient r2 = 0.97. The electrode potential change per decade of cysteine concentration was 57 mV. The minimal measurable signal response was at a cysteine concentration of 0.01 mM. The signal CV amounted to 4-6% for cysteine concentrations of 0.01 to 0.05 mM and to less than 1% for cysteine concentrations of 0.5 to 20 mM. The response time ranged from about 100 s for cysteine concentrations of 0.01 to 0.1 mM to 30 s at higher cysteine concentrations. The standard curve reproducibility was the best at cysteine concentrations from 0.1 to 20 mM. In a reaction medium containing cysteine and copper(II)-histidine complex ([His-Cu]2+) solution in 55 mM phosphate buffer pH 7.4 the electrode adequately responded to changes in cysteine concentration. Beside cysteine, the silver-mercury electrode responded also to thiol groups of homocysteine and glutathione, however, the Nernst equation slope was about half of that for cysteine.
7
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Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases.

88%
Czuczejko J., Zachara B. A., Staubach-Topczewska E., Halota W., Kędziora J.
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EN
Disturbances in the antioxidant system could play a role in pathogenesis of chronic liver disease. The aim of our study was to evaluate the levels/activities of antioxidants in blood of patients with chronic liver disease. We estimated selenium and glutathione concentrations and glutathione peroxidase activities in blood of 59 patients with chronic hepatitis B or C virus infection (group 1) and 64 patients with alcoholic, autoimmune or cryptogenic chronic liver disease (group 2). The results were compared with 50 healthy controls. Whole blood and plasma selenium and red cell glutathione concentrations were significantly lower in the patients compared with the controls. Red cell glutathione peroxidase activity was slightly reduced in both subgroups of group 1 and in group 2 with normal alanine aminotransferase values. Plasma glutathione peroxidase activity was slightly but significantly higher in patients with elevated aminotransferase values. The findings suggest that disturbances in antioxidant parameters in blood of patients with chronic liver disease may be the cause of the peroxidative damage of cells.
8
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Evaluation of plasma concentrations of selected antioxidant parameters in patients with active Crohn’s disease

75%
Szczeklik K., Krzyściak W., Cibor D., Kozioł K., Pocztar H., Pytko-Polończyk J., Mach T., Owczarek D.
Folia Medica Cracoviensia
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2018
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vol. 58
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issue 2
9
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Changes in GSH-antioxidant system induced by daunorubicin in human normal and diabetic fibroblasts.

75%
Zatorska A., Maszewski J., Jóźwiak Z.
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2003
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vol. 50
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issue 3
825-835
EN
We investigated the effect of daunorubicin on glutathione content and activity of GSH-related enzymes in cultured normal and diabetic human fibroblasts. Cells were incubated with 4 μM daunorubicin (DNR) for 2 h followed by culture in drug-free medium for up to 72 h. Treatment of diabetic cells with the drug caused a time-dependent depletion of intracellular GSH and a decrease of the GSH to total glutathione ratio. GSH depletion was accompanied by apoptotic changes in morphology of the nucleus. Analysis of GSH-related enzymes showed a significant increase of the activities of Se-dependent and Se-independent peroxidases and glutathione S-transferase. In contrast, glutathione reductase activity was reduced by 50%. Significant differences between normal and diabetic cells exposed to DNR were observed in the level of GST and Se-dependent glutathione peroxidase activities. These findings indicated that daunorubicin efficiently affects the GSH antioxidant defense system both in normal and diabetic fibroblasts leading to disturbances in glutathione content as well as in the activity of GSH-related enzymes.
10
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Glutathione and GSH-dependent enzymes in patients with liver cirrhosis and hepatocellular carcinoma

75%
Czeczot H., Ścibior D., Skrzycki M., Podsiad M.
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2006
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vol. 53
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issue 1
237-242
EN
We investigated glutathione level, activities of selenium independent GSH peroxidase, selenium dependent GSH peroxidase, GSH S-transferase, GSH reductase and the rate of lipid peroxidation expressed as the level of malondialdehyde in liver tissues obtained from patients diagnosed with cirrhosis or hepatocellular carcinoma. GSH level was found to be lower in malignant tissues compared to adjacent normal tissues and it was higher in cancer than in cirrhotic tissue. Non-Se-GSH-Px activity was lower in cancer tissue compared with adjacent normal liver or cirrhotic tissue, while Se-GSH-Px activity in cancer was found to be similar to its activity in cirrhotic tissue and lower compared to control tissue. An increase in GST activity was observed in cirrhotic tissue compared with cancer tissue, whereas the GST activity in cancer was lower than in adjacent normal tissue. The activity of GSH-R was similar in cirrhotic and cancer tissues, but higher in cancer tissue compared to control liver tissue. An increased level of MDA was found in cancer tissue in comparison with control tissue, besides its level was higher in cancer tissue than in cirrhotic tissue. Our results show that the antioxidant system of cirrhosis and hepatocellular carcinoma is severely impaired. This is associated with changes of glutathione level and activities of GSH-dependent enzymes in liver tissue. GSH and enzymes cooperating with it are important factors in the process of liver diseases development.
11
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Hydrogen sulfide generation from l-cysteine in the human glioblastoma-astrocytoma U-87 MG and neuroblastoma SHSY5Y cell lines

75%
Bronowicka-Adamska P., Bentke A., Wróbel M.
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2017
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vol. 64
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issue 1
171-176
EN
Hydrogen sulfide (H2S) is endogenously synthesized from l-cysteine in reactions catalyzed by cystathionine beta-synthase (CBS, EC 4.2.1.22) and gamma-cystathionase (CSE, EC 4.4.1.1). The role of 3-mercaptopyruvate sulfurtransferase (MPST, EC 2.8.1.2) in H2S generation is also considered; it could be important for tissues with low CTH activity, e.g. cells of the nervous system. The expression and activity of CBS, CTH, and MPST were detected in the human glioblastoma-astrocytoma (U-87 MG) and neuroblastoma (SHSY5Y) cell lines. In both cell lines, the expression and activity of MPST were the highest among the investigated enzymes, suggesting its possible role in the generation of H2S. The RP-HPLC method was used to determine the concentration of cystathionine and alpha-ketobutyrate, products of the CBS- and CTH-catalyzed reactions. The difference in cystathionine levels between cell homogenates treated with totally CTH-inhibiting concentrations of dl-propargylglycine and without the inhibitor was used to evaluate the activity of CBS. The higher expression and activity of CBS, CTH and MPST in the neuroblastoma cells were associated with more intensive generation of H2S in the presence of 2 mM cysteine. A threefold higher level of sulfane sulfur, a potential source of hydrogen sulfide, was detected in the astrocytoma cells in comparison to the neuroblastoma cells.
12
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Recent advances in understanding plant response to sulfur-deficiency stress

75%
Lewandowska M., Sirko A.
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2008
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vol. 55
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issue 3
457-471
EN
Sulfur is an essential macronutrient for all living organisms. Plants are able to assimilate inorganic sulfur and incorporate it into organic compounds, while animals rely entirely on organic sources of sulfur. In the last decades sulfate availability in soils has become the major limiting factor for plant production in many countries due to significant reduction of anthropogenic sulfur emission forced by introducing stringent environmental legislation. The sulfur flux after transferring plants from optimal conditions to sulfur deficiency is regulated on multiple levels including transcription, translation and activity of enzymes needed for sulfate assimilation and synthesis of sulfur-containing metabolites. Most of these regulatory steps are not yet fully characterized. Plant responses to sulfur limitation are complex and can be divided into phases depending on the degree of sulfur shortage. The initial responses are limited to adaptations within sulfur metabolic pathway, while multiple metabolic pathways and developmental process are affected when sulfur shortage becomes more severe. The major aim of this work is a comprehensive review of recent progress in understanding the regulation of plant adaptations to sulfur deficit.
13
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Developmental changes in the levels and redox potentials of main hemolymph thiols/disulfides in the Jamaican field cricket Gryllus assimilis

63%
Sadowska-Bartosz I., Furmaniak P., Bieszczad-Bedrejczuk E., Bartosz G., Głowacki R.
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2017
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vol. 64
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issue 3
503-506
EN
Main thiols and disulfides were determined in the hemolymph of the Jamaican field cricket Gryllus assimilis at various developmental stages. On the basis of these data, redox potentials of the glutathione, cysteine and homocysteine redox systems were calculated. The concentrations of all thiols studied decreased during development (at a stage of 6 molts) with respect to young crickets, and increased again in adult insects. Redox potentials of the glutathione and cysteine systems increased from values of -131.0±5.6 mV and -86.9±17.1 mV, respectively in young crickets to -58.0±3.6 mV and -36.1±4.2 mV, respectively, at the stage of 6 molts and decreased to values of -110.4±24.8 mV and -66.3±12.2 mV, respectively, in adult insects. Redox potentials of the glutathione and cysteine systems in the hemolymph of young and adult insects were similar to those reported for human plasma.
14
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The γ-glutamyltransferase activity and non-protein sulfhydryl compounds levels in rat kidney of different age groups.

63%
Włodek P., Sokołowska M., Smoleński O., Włodek L.
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2002
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vol. 49
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issue 2
501-507
EN
The present work was aimed to obtain information about age-dependent changes of γ-glutamyltransferase (GGT) activity and the levels of non-protein sulfhydryl compounds (NPSH) in rat kidneys. In addition, protein-bound cysteine (PB-Cys), sulfane sulfur compounds and reactive oxygen species (ROS) were estimated The results indicate that the activity of GGT and NPSH levels in the kidneys are reduced with age. At the same time, a significant increase in the level of protein-bound cysteine was observed. Simultaneously, the content of sulfane sulfur compounds was increased in the group of the oldest animals. These findings indicate that the capacity for extracellular glutathione degradation and, in consequence, the availability of cysteine for intracellular glutathione biosynthesis may be impaired. The increased PB-Cys level indicates potentiation of the thiolation reaction, i.e. development of protein-mixed disulfides. These results reveal age dependent disturbances in the thiol-disulfide equilibrium in the kidneys which leads to an imbalance between pro- and antioxidatory processes.
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Reactions of Pseudomonas aeruginosa pyocyanin with reduced glutathione

63%
Cheluvappa R., Shimmon R., Dawson M., Hilmer S. N., Le Couteur D. G.
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2008
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vol. 55
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issue 3
571-580
EN
Pseudomonas aeruginosa is the most common cause of chronic and recurrent lung infections in patients with cystic fibrosis (CF) whose sputa contain copious quantities of P. aeruginosa toxin, pyocyanin. Pyocyanin triggers tissue damage mainly by its redox cycling and induction of reactive oxygen species (ROS). The reactions between reduced glutathione (GSH) and pyocyanin were observed using absorption spectra from spectrophotometry and the reaction products analysed by nuclear magnetic resonance imaging. Pyocyanin reacted with GSH non-enzymatically at 37°C resulting in the production of red-brown products, spectophotometrically visible as a 480 nm maximum absorption peak after 24 h of incubation. The reaction was concentration-dependent on reduced glutathione but not on pyocyanin. Minimizing the accessibility of oxygen to the reaction decreased its rate. The anti-oxidant enzyme catalase circumvented the reaction. Proton-NMR analysis demonstrated the persistence of the original aromatic ring and the methyl-group of pyocyanin in the red-brown products. Anti-oxidant agents having thiol groups produced similar spectophotometrically visible peaks. The presence of a previously unidentified non-enzymatic GSH-dependent metabolic pathway for pyocyanin has thus been identified. The reaction between pyocyanin and GSH is concentration-, time-, and O2-dependent. The formation of H2O2 as an intermediate and the thiol group in GSH seem to be important in this reaction.
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