Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Crude cell-free extracts of nine strains of Streptomyces tested for nitroalkane-oxidizing activity showed production of nitrous acid from 2-nitropropane, 1-nitropropane, nitroethane, nitromethane, and 3-nitropropionic acid. These substrates were utilized in most strains but to a decreasing extent in the order given, and different strains varied in their relative efficiency of oxidation. p-Nitrobenzoic acid, p-aminobenzoic acid, enteromycin, and omega-nitro-l-arginine were not attacked. d-Amino acid oxidase, glucose oxidase, glutathione S-transferase, and xanthine oxidase, enzymes potentially responsible for the observed oxidations in crude cellfree extracts, were present at concentrations too low to play any significant role. A nitroalkane-oxidizing enzyme from streptozotocin-producing Streptomyces achromogenes subsp. streptozoticus was partially purified and characterized. It catalyzes the oxidative denitrification of 2-nitropropane as follows: 2CH(3)CH(NO(2))CH(3) + O(2) --> 2CH(3)COCH(3) + 2HNO(2). At the optimum pH of 7.5 of the enzyme, 2-nitropropane was as good a substrate as its sodium salt; t-nitrobutane was not a substrate. Whereas Tiron, oxine, and nitroxyl radical acted as potent inhibitors of this enzyme, superoxide dismutase was essentially without effect. Sodium peroxide abolished a lag phase in the progress curve of the enzyme and afforded stimulation, whereas sodium superoxide did not affect the reaction. Reducing agents, such as glutathione, reduced nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide phosphate, reduced form, as well as thiol compounds, were strongly inhibitory, but cyanide had no effect. The S. achromogenes enzyme at the present stage of purification is similar in many respects to the enzyme 2-nitropropane dioxygenase from Hansenula mrakii. The possible involvement of the nitroalkane-oxidizing enzyme in the biosynthesis of antibiotics that contain a nitrogen-nitrogen bond is discussed.
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PMID:Nitroalkane oxidation by streptomycetes. 3 65

Activation of glutathione transferase activity in rat liver microsomes under a variety of conditions producing oxidative stress was investigated. Neither hydrogen peroxide (10 mM) (added or produced endogenously by glucose + glucose oxidase) nor duroquinone together with an NADPH-regenerating system (which generates the superoxide anion radical) had any significant effect on the glutathione transferase activity towards 1-chloro-2,4-dinitrobenzene. On the other hand, incubation of microsomes with 1 mM noradrenaline (which autooxidizes and generates superoxide anion radical) gave a 160% activation, as shown earlier (Aniya and Anders, J Biol Chem 264: 1998-2002, 1989). This was taken as an indication that microsomal glutathione transferase could be activated by oxidative stress. Here, we demonstrate that activation by this compound is due to covalent binding (presumably of the quinone formed during autooxidation). The xanthine/xanthine oxidase system, which generates the superoxide anion radical and hydrogen peroxide, increases microsomal glutathione transferase activity, but this activation was not dependent on the presence of xanthine. Western blots of microsomes treated with xanthine oxidase revealed that activation was due to proteolysis (presumably by contaminating proteases in the xanthine oxidase). In conclusion, there is no firm evidence that rat liver microsomal glutathione transferase is activated directly by reduced oxygen species in the microsomal system. The possibility remains that oxidative stress triggers secondary mechanisms such as generation of reactive intermediates and/or activation of proteolysis, which can in turn increase enzyme activity.
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PMID:Mechanism of activation of rat liver microsomal glutathione transferase by noradrenaline and xanthine oxidase. 157 69

Recent evidence supports the concept that Adriamycin cytotoxicity may be mediated by drug semiquinone free radical and oxyradical generation. We tested this hypothesis further by exposing drug-sensitive (WT) and 500-fold Adriamycin-resistant MCF-7 human breast tumor cells (ADRR) to exogenous superoxide- and hydrogen peroxide-generating systems and subsequently monitored cell proliferation as a measure of cytotoxicity. The ADRR tumor cells tolerated a 4-fold greater exposure than sensitive cells to superoxide generated by the xanthine/xanthine oxidase system. Likewise, exposure to hydrogen peroxide produced by the action of glucose oxidase on glucose revealed a 4-fold diminished susceptibility of the drug-resistant cells to this reduced form of oxygen. Similar results were obtained by the direct application of hydrogen peroxide to cells. For both cell lines, cytotoxicity was dependent upon the magnitude and the duration of reactive oxygen exposure. When WT and ADRR cells were cultured under hyperoxia (95% O2:5% CO2), in order to stimulate the intracellular production of oxyradicals, proliferation was inhibited to a greater extent in the drug-sensitive cell line. Additionally, hyperoxia potentiated the cytotoxicity of Adriamycin to both sensitive and drug-resistant cells, but the effect depended upon the concentration of the drug. Under hyperoxic conditions, Adriamycin caused oxygen radical-dependent cytotoxicity to the WT tumor cells at clinically relevant drug concentrations as low as 2 to 3 nM. With ADRR tumor cells, hyperoxia increased the cytotoxicity of Adriamycin at concentrations above 5 microM. Paradoxically, both the WT and the ADRR tumor cells were equally susceptible to the cytotoxic effects of gamma irradiation. It is known that the Adriamycin-resistant MCF-7 cells greatly overexpress glutathione peroxidase and glutathione transferase activities; however, other biochemical defenses against reactive drug intermediates and oxygen radicals have been reported to be similar in the two cell lines. We have reexamined those observations in this report. The resistance of ADRR breast tumor cells to Adriamycin appears to be associated with a developed tolerance to superoxide, most likely because of a twofold increase in superoxide dismutase activity, and a decreased susceptibility to hydrogen peroxide, most likely because of 12-fold augmented selenium-dependent glutathione peroxidase activity. Acting in concert, these two enzymes would decrease the formation of hydroxyl radical from reduced molecular oxygen intermediates.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Differential oxygen radical susceptibility of adriamycin-sensitive and -resistant MCF-7 human breast tumor cells. 253 95

To compare the protein complement of royal jelly (RJ) from high RJ producing honeybees ( Apis mellifera L.), a strain of A. mellifera artificially selected for increased RJ production from Italian honeybees in China for more than two decades was compared to those of native Italian honeybees ( A. mellifera L.) and Carnica honeybees ( A. mellifera C.); the protein in RJ from these three strains of honeybees was partially identified by using a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS), and a protein engine identification tool applied to the honeybee genome. The results showed that 152, 157, and 137 proteins were detected in the three species of RJ; among which 57, 57, 51 high abundant proteins ere identified, respectively. Most identifited spots, 45, 45, 41, were assigned to major royal jelly proteins (MRJPs). Remarkable differences were found in the heterogeneity of the MRJPs, in particular, MRJP3. Also, 3-glucose oxidase, 1-peroxiredoxin (PRDX), and 1-glutathione S-transferase (GST) S1 were identified in three RJ samples. Furthermore, during the determination of the peptides mass fingerprinting (PMF) of each spot, for the first time, PRDX and GST S1 proteins have been identified in RJ. Thus, the results suggest that the protein complement of high RJ producing honeybees is not different compared to native Italian honeybees, while a difference remains between Carnica honeybees.
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PMID:Proteomic analysis of royal jelly from three strains of western honeybees (Apis mellifera). 1792 47

Protein changes in fresh royal jelly (RJ) were compared when stored at -20, 4 degrees C, and room temperature (RT) for 12 months. Protein was partially identified using combinations of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS), gel filtration chromatography, nanoLC MS/MS, and a protein engine identification tool applied to the honeybee genome. Significantly more protein spots were found in fresh (85 spots) and -20 degrees C (81 spots) stored RJ than in samples stored at 4 degrees C (73 spots) and at RT (70 spots) for 1 year. Most identified spots, 56, 57, 51, 46, corresponding to RJ sample of the fresh, -20 degrees C, 4 degrees C, and RT, were assigned to major royal jelly proteins (MRJPs). Marked differences were found in the heterogeneity of the MRJPs, in particular, MRJP3. The quantity of MRJP1 decreased significantly following the temperature trend in all images, but MRJP 2 and -3 did not increase or decrease following the temperature trend, thus, suggesting that MRJP 1-3 are sensitive to temperature. However, MRJP4, 5, glucose oxidase (GOD), peroxiredoxin (PRDX), and glutathione S-transferase (GST) S1 were clearly absent in all images in samples held at RT for 1 year. This indicates that they are the proteins most sensitive to storage temperature and protein markers for freshness of RJ. Combining chromatography and nanoLC MS/MS results, we tentatively conclude that MRJP5 is a reliable freshness marker and that the best way to maintain quality of RJ is under freezing conditions.
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PMID:Proteomics analysis of major royal jelly protein changes under different storage conditions. 1859 15

In this study, we compared royal jelly (RJ) produced by Apis mellifera ligustica and Apis cerana cerana in production, protein profiles, and abundances using proteomic approaches. The RJ proteome was displayed using two-dimensional gel electrophoresis (2DGE), and proteins were identified using MALDI-TOF MS and LC-Chip/ESI-QTOF MS. Differences in the RJ proteome between the two bee species were validated using western-blot analysis. RJ production by A. cerana cerana (3.21 +/- 0.43 g) is significantly lower than that of A. mellifera ligustica (80.5 +/- 7.83 g). The 2DGE based MS approach identified 52 and 60 proteins in the RJ of A. mellifera ligustica and A. cerana cerana, respectively. The majority of the identified proteins were major royal jelly proteins (MRJPs). Peroxiredoxin 2540, glutathione S-transferase S1, and MRJP5 were detected only in the RJ of A. mellifera ligustica, and MRJP1 was the most abundant MRJP. In contrast, MRJP7 was found only in the RJ of A. cerana cerana. But, similar to A. mellifera ligustica, MRJP1 was found most abundantly in this case too. In this study, glucose oxidase was identified for the first time in the A. cerana cerana RJ. Comparing the protein levels of MRJP1, 2, 3, 4, and 5 between the two species, they were significantly higher in the RJ of A. mellifera ligustica than in A. cerana cerana. This observation was supported by Western blot analysis using anti-MRJP1, 2, 3 antibodies. The result suggested that A. mellifera ligustica needs more nutrition to nurse the developing larvae and queens as compared to that of A. cerana cerana. This study improved our understanding of protein composition of RJ from Western and Eastern honeybees. RJ produced by A. mellifera ligustica exceeds the RJ from A. cerana cerana both in terms of production and health purposes.
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PMID:Royal jelly proteome comparison between A. mellifera ligustica and A. cerana cerana. 2030 72

Commercially and traditionally managed bees were compared for oxidative stress (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and malondialdehyde (MDA)), the prevalence of parasites (Lotmaria passim, Crithidia mellificae and Nosema ceranae/apis) and social immunity (glucose oxidase gene expression). The research was conducted on Pester plateau (Serbia-the Balkan Peninsula), on seemingly healthy colonies. Significant differences in CAT, GST and SOD activities (p < 0.01), and MDA concentrations (p < 0.002) were detected between commercial and traditional colonies. In the former, the prevalence of both L. passim and N. ceranae was significantly (p < 0.05 and p < 0.01, respectively) higher. For the first time, L. passim was detected in honey bee brood. In commercial colonies, the prevalence of L. passim was significantly (p < 0.01) lower in brood than in adult bees, whilst in traditionally kept colonies the prevalence in adult bees and brood did not differ significantly. In commercially kept colonies, the GOX gene expression level was significantly (p < 0.01) higher, which probably results from their increased need to strengthen their social immunity. Commercially kept colonies were under higher oxidative stress, had higher parasite burdens and higher GOX gene transcript levels. It may be assumed that anthropogenic influence contributed to these differences, but further investigations are necessary to confirm that.
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PMID:Oxidative Stress, Endoparasite Prevalence and Social Immunity in Bee Colonies Kept Traditionally vs. Those Kept for Commercial Purposes. 3234 95