scholarly journals Glutathione S-transferases of mouse lung. Selective binding of benzo[a]pyrene metabolites by the subunits which are preferentially induced by t-butylated hydroxyanisole

1987 ◽  
Vol 243 (2) ◽  
pp. 351-358 ◽  
Author(s):  
S V Singh ◽  
G Creadon ◽  
M Das ◽  
H Mukhtar ◽  
Y C Awasthi

Six isoenzymes of glutathione S-transferase (GST) present in mouse lung have been purified and characterized. GST I (pI 9.8) is a dimer of Mr-26,500 subunits and GST II is a heterodimer of Mr-26,500 and -22,000 subunits, and GST III (pI 7.9) and IV (pI 6.4) are dimers of Mr-24,500 subunits. GST V (pI 5.7) is a heterodimer of Mr-24,500 and -23,000 subunits, whereas GST VI (pI 4.9) is a dimer of Mr-23,000 subunits. Immunological studies indicate that the Mr-24,500 subunits present in GST III (pI 7.9) are distinct from those present in GST IV (pI 6.4) and V (pI 5.7). Structural and immunological studies provide evidence that at least five distinct types of subunits in their different binary combinations give rise to various GST isoenzymes of mouse lung. These isoenzymes express varying degrees of catalytic activities towards a wide range of electrophilic substrates including benzo[a]pyrene 7,8-oxide and benzo[a]pyrene 4,5-oxide. The dietary antioxidant t-butylated hydroxyanisole (BHA) preferentially induces GST II and III. Also, these two isoenzymes selectively bind benzo[a]pyrene (B[a]P) metabolites, indicating that they play an important physiological role in the detoxification of B[a]P metabolites. The preferential induction of the GST isoenzymes involved in the detoxification of activated B[a]P metabolites indicates that the anti-neoplastic activity of BHA against B[a]P-induced neoplasia in mouse lung [Wattenberg (1973) J. Natl. Cancer Inst. 50, 1541-1544] may be due to the enhanced detoxification of B[a]P metabolites.

1989 ◽  
Vol 263 (2) ◽  
pp. 393-402 ◽  
Author(s):  
L I McLellan ◽  
J D Hayes

A novel cytosolic Alpha class glutathione S-transferase (GST) that is not normally expressed in mouse liver was found to be markedly induced (at least 20-fold) by the anti-carcinogenic compound butylated hydroxyanisole. This enzyme (designated GST Ya1 Ya1) did not bind to either the S-hexylglutathione-Sepharose or the glutathione-Sepharose affinity matrices, and purification was achieved by using bromosulphophthalein-glutathione-Sepharose. The purified isoenzyme, which comprises subunits of Mr 25,600, was characterized, and its catalytic, electrophoretic, immunochemical and structural properties are documented. GST Ya1 Ya1 was shown to be distinct from the Alpha class GST that is expressed in normal mouse liver and is composed of 25,800-Mr subunits; the Alpha class isoenzyme that is constitutively expressed in the liver is now designated GST Ya3 Ya3. Hepatic concentrations of GST Ya3 Ya3 were not significantly affected when mice were treated with butylated hydroxyanisole. Both Pi class GST (subunit Mr 24,800) and Mu class GST (subunit Mr 26,400) from female mouse liver were induced by dietary butylated hydroxyanisole. By contrast, hepatic concentrations of microsomal GST (subunit Mr 17,300) were unaffected.


FEBS Letters ◽  
1992 ◽  
Vol 313 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Piotr Zimniak ◽  
Michael A. Eckles ◽  
Manju Saxena ◽  
Yogesh C. Awasthi

2021 ◽  
Vol 9 (9) ◽  
pp. 1025
Author(s):  
Chiara Lauritano ◽  
Ylenia Carotenuto ◽  
Vittoria Roncalli

The glutathione S-transferase (GST) is a complex family of phase II detoxification enzymes, known for their ability to catalyze the conjugation of the reduced form of glutathione (GSH) to a wide variety of endogenous and exogenous electrophilic compounds for detoxification purposes. In marine environments, copepods are constantly exposed to multiple exogenous stressors, thus their capability of detoxification is key for survival. Full identification of the GST family in copepods has been limited only to few species. As for insects, the GST family includes a wide range of genes that, based on their cellular localization, can be divided in three classes: cytosolic, microsomal, and mitochondrial. The role of GSTs might have class-specific features, thus understanding the nature of the GST family has become crucial. This paper covers information of the GST activity in marine copepods based on studies investigating gene expression, protein content, and enzymatic activity. Using published literature and mining new publicly available transcriptomes, we characterized the multiplicity of the GST family in copepods from different orders and families, highlighting the possible role of these genes as biomarker for ocean health status monitoring.


1976 ◽  
Vol 160 (2) ◽  
pp. 223-229 ◽  
Author(s):  
B F Hales ◽  
A H Neims

The glutathione S-transferases are a group of proteins with overlapping substrate specificities and ligand-binding capacities. This report examines certain approaches to the measurement of transferase B (ligandin) in the rat liver. The ratio of catalytic activities toward 1-chloro-2,4-dinitrobenzene and 1,2-dichloro-4-nitrobenzene gives some indication of the relative proportions of the various transferases present in 100 000 g supernatants. The fraction of catalytic activity towards 1-chloro-2,4-dinitrobenzene, due to transferase B, was best measured by immunoprecipitation with anti-(transferase B). Male rat liver exhibited three times more activity towards 1,2-dichloro-4-nitrobenzene than female tissue; however, the activities towards 1-chloro-2,4-dinitrobenzene were almost identical. By assuming a specific activity of 11 mumol/min per mg, immunoprecipitable transferase B comprised 4.5 +/- 0.2% of total protein in the 100 000 g supernatant of female rat liver, and 70% of the transferase activity towards 1-chloro-2,4-dinitrobenzene. The amount of transferase B in the 100 000 g supernatant from male rat liver is significantly lower with respect to both fraction of total protein (3.3 +/- 0.2%) and overall transferase activity towards 1-chloro-2,4-dinitrobenzene (48%). Hypophysectomy eliminated this sex difference in the hepatic concentration of glutathione S-transferase B.


2019 ◽  
Vol 2 (2) ◽  
pp. 1-21 ◽  
Author(s):  
Elina Mitra ◽  
Bharati Bhattacharjee ◽  
Palash Kumar Pal ◽  
Arnab Kumar Ghosh ◽  
Sanatan Mishra ◽  
...  

Cadmium (Cd) is a notorious environmental pollutant known for its wide range of toxicities to organisms. Thus, the present study is designed to examine whether melatonin, a potent antioxidant, protects against Cd-induced oxidative damage in the heart, liver and kidney of rats. Cd treatment at a dose of 0.44 mg/kg for 15 days caused severe damage in all these organs. These included significantly increased activities of SGPT, SGOT, lactate dehydrogenase- 1 and 5 and ALP and levels of total lactate, creatinine, lipid peroxidation, protein carbonyl content and reduced glutathione while the activities of superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase along with mitochondrial pyruvate dehydrogenase, isocitrate dehydrogenase, α-keto glutarate dehydrogenase, succinate dehydrogenase, NADH-cytochrome-c-oxidoreductase and cytochrome-c-oxidase were significantly reduced by Cd. However, if melatonin was given orally 30 min before Cd injection, all these alterations induced by Cd were significantly preserved by melatonin. Histological observations also demonstrated that Cd exposure caused cellular lesions, promoting necrotic or apoptotic changes. Notably, all these changes were significantly protected by melatonin. The results suggest that melatonin is a beneficial molecule to ameliorate Cd-induced oxidative damage in the heart, liver and kidney tissues of rats with its powerful antioxidant capacity, heavy metal chelating activity and competition of binding sites with Cd to the GSH and catalase.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 629
Author(s):  
Aniello Costantini ◽  
Valeria Califano

Lipases are ubiquitous enzymes whose physiological role is the hydrolysis of triacylglycerol into fatty acids. They are the most studied and industrially interesting enzymes, thanks to their versatility to promote a plethora of reactions on a wide range of substrates. In fact, depending on the reaction conditions, they can also catalyze synthesis reactions, such as esterification, acidolysis and transesterification. The latter is particularly important for biodiesel production. Biodiesel can be produced from animal fats or vegetable oils and is considered as a biodegradable, non-toxic and renewable energy source. The use of lipases as industrial catalysts is subordinated to their immobilization on insoluble supports, to allow multiple uses and use in continuous processes, but also to stabilize the enzyme, intrinsically prone to denaturation with consequent loss of activity. Among the materials that can be used for lipase immobilization, mesoporous silica nanoparticles represent a good choice due to the combination of thermal and mechanical stability with controlled textural characteristics. Moreover, the presence of abundant surface hydroxyl groups allows for easy chemical surface functionalization. This latter aspect has the main importance since lipases have a high affinity with hydrophobic supports. The objective of this work is to provide an overview of the recent progress of lipase immobilization in mesoporous silica nanoparticles with a focus on biodiesel production.


2011 ◽  
Vol 7 (2-4) ◽  
pp. 199-203 ◽  
Author(s):  
Farah Lotfi Kashani ◽  
Dor Mohammad Kordi-Tamandani ◽  
Roya Sahranavard ◽  
Mohammad Hashemi ◽  
Farzaneh Kordi-Tamandani ◽  
...  

Glutathione S-transferases (GSTs) are major intracellular antioxidants, which, impaired in their function, are involved in the progress of schizophrenia (SCZ). The aim of this case-control study was to investigate the association between the polymorphism of glutathione S-transferases M1 (GSTM1), T1 (GSTT1), the glutathione S-transferase P1 gene (GSTP1) and SCZ. We isolated genomic DNA from peripheral blood of 93 individuals with SCZ and 99 healthy control subjects' genotypes analyzing them for GSTM1, GSTT1 and GSTP1 using polymerase chain reaction. The analysis of the gene–gene interaction between GSTs indicated that the magnitude of the association was greater for the combined AG/GSTT1 & GSTM1 genotypes (OR = 2.51; 95% CI: 1.13–5.63, P = 0.02). The AG and combined AG + GG genotypes of GSTP1 increased the risk of SCZ (OR = 1.83; 95% CI: 0.94–3.75 and OR = 1.71; 95% CI: 0.92–3.19, respectively). The genotypes of GSTT/NULL, NULL/GSTM and NULL/NULL increased the risk of SCZ (OR = 2.05; 95% CI: 0.9–4.74; OR = 2.0; 95% CI: 1.68–2.31; and OR = 1.8; 95% CI: 0.57–2.46, respectively). The present study supports previous data that suggest that impairment in the function of GSTs genes may increase the risk of SCZ.


Author(s):  
Saira Nawaz ◽  
Hafiz Muhammad Tahir ◽  
Muhammad Asif Mahmood ◽  
Muhammad Summer ◽  
Shaukat Ali ◽  
...  

Abstract Aedes aegypti (Linnaeus, 1762) is a major vector responsible for dengue transmission. Insecticides are being used as the most effective tool to control vector populations in Lahore, Pakistan. Control of Ae. aegypti is threatened by the development of resistance against insecticides. The current status of insecticide resistance was evaluated against pyrethroids (deltamethrin, cypermethrin, and lambda-cyhalothrin) in different populations of Lahore (Model Town, Mishri Shah, Sadar Cantt, Walton, and Valencia). The susceptibility of the larval and adult populations was tested following the standard WHO guidelines. Moderate to high levels of resistance were found against pyrethroids in the larval (RR50: 3.6–27.2 and RR90: 5–90) and adult populations (percentage mortality < 98%). Biochemical assays revealed a statistically significant increase in the enzyme level in all field populations compared to the laboratory strain. The value of esterase was one-fold higher, monooxygenase was 3.9- to 4.7-fold higher, and glutathione S-transferases was 1.9- to 2.6-fold higher in field populations compared to the laboratory strain. These results depict the presence of resistance against deltamethrin, cypermethrin, and lambda-cyhalothrin in field populations of Lahore mediated by metabolic enzymes i.e. esterases, monooxygenases, and glutathione S-transferase.


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