Selenium-independent glutathione peroxidase activity associated with glutathione S-transferase from the housefly, Musca domestica

Simmons, Thomas W.; Jamall, Ijaz S.; Lockshin, Richard A.

doi:10.1016/0305-0491(89)90350-7

Cited by 34 publications

(24 citation statements)

References 24 publications

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“…Not only was the relationship not antagonistic, the two compounds had a significant potentiation effect, causing much greater toxicity that we would have expected from their individual toxicities. We speculate that the reason for the potentiation rather than antagonism may be because of the lack of Sedependent glutathione peroxidase in some insects (Simmons et al 1989), which acts as an important component of the antioxidant system in mammals. This potentiation that we observed between selenate and methylmercury was also evident in the decreased developmental rate of M. scalaris.…”

Section: Discussionmentioning

confidence: 94%

Individual and Joint Actions of Selenate and Methylmercury on the Development and Survival of Insect Detritivore Megaselia scalaris (Diptera: Phoridae)

Jensen

Johnson

Trumble

2006

Arch Environ Contam Toxicol

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Abstract. Despite the important roles played by insects in most ecosystems, surprisingly little is known about how anthropogenic pollutants or their mixtures interact to affect insect populations. The independent and joint actions of selenate and methylmercury on a ubiquitous insect detritivore, Megaselia scalaris (Loew), were determined in this study. Ovipositing females did not distinguish between untreated food sources and those contaminated with toxic concentrations of selenate, methylmercury, or both chemicals in combination. Even at the highest concentrations of pollutants, no negative effects were observed for the egg stage. However, larval survival was significantly decreased and development significantly prolonged by selenate and methylmercury individually at low or intermediate ecologically relevant treatment levels. Potentiation was strongly evident because mixtures containing concentrations as little as only 1% of the respective individual median lethal tolerances (LC 50 s) caused significantly more mortality and delayed larval development than would be expected from the responses selenate and methylmercury elicit individually. However, survival and pupal development was not affected at any rate tested. Female fecundity was significantly decreased by methylmercury but not by selenate or mixture treatments. The relative toxicity to M. scalaris of each of the individual and joint treatments was selenate (LC 50 = 260 lg/g) < methylmercury (LC 50 = 22 lg/g) < the mixture at approximately 5% of the LC 50 concentration of each of the components (12 lg/g selenate plus 1.0 lg/g methylmercury). The increased mortality and delayed larval development within sites contaminated by selenate, methylmercury, or combination of the two have substantial implications for the ecology, population dynamics, and sustainability of M. scalaris populations. If these results can be extrapolated to other arthropod detritivores, ecosystem food-web function may be substantially affected.As a class, insects dominate the world in which we live. More than 70% of all known species are insects, and

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Section: Discussionmentioning

confidence: 94%

Individual and Joint Actions of Selenate and Methylmercury on the Development and Survival of Insect Detritivore Megaselia scalaris (Diptera: Phoridae)

Jensen

Johnson

Trumble

2006

Arch Environ Contam Toxicol

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“…Characterisation of GSTX2-2 GST activity against 1-choro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) was measured according to the method of Habig et al (1974). Glutathione peroxidase activity was determined at 340 nm by coupling the reduction of cumene hydroperoxide (CHP) by GSH to the oxidation of nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH) by oxidised GSSG with glutathione reductase as described previously (Simmons et al, 1989). DDT-dehydrochlorinase activity was determined by conversion of DDT to DDE detected by high-performance liquid chromatography (HPLC) as described previously (Prapanthadara et al, 2000).…”

Section: Maldi-tof Mass Spectrometry Analysismentioning

confidence: 99%

The Aedes aegypti glutathione transferase family

Lumjuan

Stevenson

Prapanthadara

et al. 2007

Insect Biochemistry and Molecular Biology

118

117

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“…The results obtained by this method were initially confirmed by an HPLC-based enzyme assay (Kreuz et al, 1989). GSH peroxidase activity was measured according to the method of Simmons et al (1989). The hydroperoxides of linolenic acid and arachidonic acid used as GSH peroxidase substrates were prepared by the method of Graff et al (1990).…”

Section: Enzyme Assaysmentioning

confidence: 99%

An Inducible Glutathione S-Transferase in Soybean Hypocotyl Is Localized in the Apoplast

Flury¹,

Wagner²,

Kreuz³

1996

Plant Physiology

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Clutathione S-transferases (CSTs) with additional activities as fatty acid hydroperoxidases were investigated in soybean (Glycine max 1.) hypocotyls. Aside from the GSTs present in total soluble tissue extracts, enzyme activities and distinct immunoreactive GST polypeptides were also detected in the intercellular washing fluid. Whereas the intracellular isoenzymes were both constitutive and inducible, apoplastic CST and glutathione peroxidase was detectable only in tissues treated with the known GST inducer 2,3,5-triiodobenzoic acid. Monensin inhibited the induced accumulation of apoplastic CST but did not affect the intracellular isoforms. The discovery of apoplastic inducible CST will be discussed in light of the putative function of these enzymes in plants.The GSTs (EC 2.5.1.18) are a family of proteins with severa1 activities (Wilce and Parker, 1994;Marrs, 1996). GSTs catalyze the nucleophilic attack of the thiol of GSH to electrophilic substrates, typically resulting in the formation of GSH conjugates. GSTs are usually dimeric proteins with subunit molecular masses of 24 to 30 kD; they are organized in gene families that produce multiple isoenzymes in eukaryotic organisms. GSTs are mostly soluble cytoplasmic enzymes, but microsomal isoforms are also known in both plants and animals. GSTs conjugate GSH to various xenobiotics, e.g. drugs and pesticides, which is often a key step in their metabolic detoxification and elimination from the cytoplasm (Lamoureux and Rusness, 1989;Kreuz et al., 1996;Reinemer et al., 1996).The multitude of GST isoenzymes in plants and their inducibility by diverse biotic and abiotic factors has been the primary focus of research in recent years. Yet, knowledge about the physiological substrate(s) and function(s) of plant GSTs is only slowly beginning to emerge. Thus, GSTs have been implicated in the conjugation of cinnamic acid and of anthocyanins and in the binding of IAA (Edwards and Dixon, 1991;Marrs, 1996). Some GST isoenzymes display additional activities; for example, the selenium-independent GSH peroxidases catalyze the reduction of fatty acid hydroperoxides with concomitant formation of GSSG (Bartling et al., 1993). Such hydroperoxides are formed by the action of active oxygen species that are generated both as normal by-products of aerobic metabolism and as the result of pathogen infection or exposure to certain abiotic * Corresponding author; e-mail klaus-eugen.kreuz@chbs.mhs. ciba.com; fax 41-61-697-8455.agents. Organic hydroperoxides are potentially cytotoxic, and their removal by GSH peroxidase activity has thus been implicated in the protection of tissues against oxidative stress (Ketterer et al., 1990).In this report we describe the isolation and characterization of GSTs from soybean (Glycine max L.) that display high GSH peroxidase activity toward hydroperoxides of linolenic acid and arachidonic acid. In addition to the soluble intracellular isoenzymes, GST and GSH peroxidase were also found in the intercellular washing fluid of hypocotyls. These apoplastic enzyme ac...

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Selenium-independent glutathione peroxidase activity associated with glutathione S-transferase from the housefly, Musca domestica

Cited by 34 publications

References 24 publications

Individual and Joint Actions of Selenate and Methylmercury on the Development and Survival of Insect Detritivore Megaselia scalaris (Diptera: Phoridae)

Individual and Joint Actions of Selenate and Methylmercury on the Development and Survival of Insect Detritivore Megaselia scalaris (Diptera: Phoridae)

The Aedes aegypti glutathione transferase family

An Inducible Glutathione S-Transferase in Soybean Hypocotyl Is Localized in the Apoplast

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