scholarly journals Effects of inducers of drug metabolism on basic hepatic forms of mouse glutathione transferase

1989 ◽  
Vol 263 (3) ◽  
pp. 679-685 ◽  
Author(s):  
P Di Simplicio ◽  
H Jensson ◽  
B Mannervik
Keyword(s):  
Mouse Liver ◽  
Glutathione Transferase ◽  
Major Effect ◽  
Glutathione Transferases ◽  
Control Group ◽  
Glyoxalase I ◽  
Protein Profiles ◽  
Trans Stilbene ◽  
Cytosolic Glutathione ◽  
Gst Activity

The cytosolic glutathione transferases (GSTs) with basic pI values have been studied in mouse liver after treatment with 2,3-t-butylhydroxyanisole (BHA), cafestol palmitate (CAF), phenobarbital (PB), 3-methylcholanthrene (3-MC) and trans-stilbene oxide (t-SBO). The cytosolic GST activity was induced by all compounds except for 3-MC. Three forms of GST were isolated by means of affinity chromatography and f.p.l.c. The examination of protein profiles and enzymic activities with specific substrates showed that the three GSTs correspond to those found in control animals, i.e. GSTs MI, MII and MIII. The class Mu GST MIII accounted for the major effect of induction, whereas the class Alpha GST MI and the class Pi GST MII were unchanged or somewhat down-regulated. The greatest induction was obtained with BHA, PB and CAF. The activities of other glutathione-dependent enzymes were also studied. An increase in glutathione reductase and thioltransferase activities was observed after BHA, PB or CAF treatment; glyoxalase I and Se-dependent glutathione peroxidase were depressed in comparison with the control group in all cases studied.

scholarly journals Activation and inhibition of microsomal glutathione transferase from mouse liver

1988 ◽  
Vol 249 (3) ◽  
pp. 819-823 ◽  
Author(s):  
C Andersson ◽  
M Söderström ◽  
B Mannervik
Keyword(s):  
Molecular Mass ◽  
Mouse Liver ◽  
Glutathione Transferase ◽  
Cross Reactivity ◽  
Steep Slope ◽  
Glutathione Transferases ◽  
Inhibitor Concentration ◽  
Cytosolic Glutathione ◽  
Concentration Curves ◽  
Microsomal Glutathione

Mouse liver microsomal glutathione transferase was purified in an N-ethylmaleimide-activated as well as an unactivated form. The enzyme had a molecular mass of 17 kDa and a pI of 8.8. It showed cross-reactivity with antibodies raised against rat liver microsomal glutathione transferase, but not with any of the available antisera raised against cytosolic glutathione transferases. The fully N-ethylmaleimide-activated enzyme could be further activated 1.5-fold by inclusion of 1 microM-bromosulphophthalein in the assay system. The latter effect was reversible, which was not the case for the N-ethylmaleimide activation. At 20 microM-bromosulphophthalein the activated microsomal glutathione transferase was strongly inhibited, while the unactivated form was activated 2.5-fold. Inhibitors of the microsomal glutathione transferase from mouse liver showed either about the same I50 values for the activated and the unactivated form of the enzyme, or significantly lower I50 values for the activated form compared with the unactivated form. The low I50 values and the steep slope of the activity-versus-inhibitor-concentration curves for the latter group of inhibitors tested on the activated enzyme indicate a co-operative effect involving conversion of activated enzyme into the unactivated form, as well as conventional inhibition of the enzyme.

scholarly journals Glutathione transferases in rat hepatoma cells. Effects of ascites cells on the isoenzyme pattern in liver and induction of glutathione transferases in the tumour cells

1989 ◽  
Vol 257 (1) ◽  
pp. 215-220 ◽  
Author(s):  
M K Tahir ◽  
C Guthenberg ◽  
B Mannervik
Keyword(s):  
Glutathione Transferase ◽  
Hepatoma Cell ◽  
Normal Liver ◽  
Hepatoma Cells ◽  
Glutathione Transferases ◽  
Trans Stilbene ◽  
Cytosolic Glutathione ◽  
Fold Induction ◽  
Rat Hepatoma ◽  
Rat Hepatoma Cells

Rat hepatoma cells grown intraperitoneally as an ascites tumour were analysed with respect to their contents of cytosolic glutathione transferases. In contrast with normal liver tissue, the hepatoma cells were dominated by the class Pi glutathione transferase 7-7. All the major hepatic enzyme forms were down-regulated to almost undetectable concentrations. Livers of rats bearing ascites-hepatoma cells expressed low, but significant, amounts of protein which, by electrophoretic and immunochemical properties, appeared identical with transferase 7-7. This enzyme is not detectable in normal hepatocytes. Treatment of rats with trans-stilbene oxide induced the expression of transferase 7-7 in the livers of normal rats as well as in hepatoma-cell-bearing animals. In addition, a 2-fold induction of transferase 7-7 was measured in the hepatoma ascites cells. No significant elevation of any other enzyme forms in the hepatoma cells was noted.

scholarly journals Cytosolic glutathione transferases from rat liver. Primary structure of class alpha glutathione transferase 8-8 and characterization of low-abundance class Mu glutathione transferases

1989 ◽  
Vol 261 (2) ◽  
pp. 531-539 ◽  
Author(s):  
P Alin ◽  
H Jensson ◽  
E Cederlund ◽  
H Jörnvall ◽  
B Mannervik
Keyword(s):  
Rat Liver ◽  
Glutathione Transferase ◽  
Glutathione Transferases ◽  
Rat Lung ◽  
Cytosol Fraction ◽  
Methionine Residue ◽  
Isoelectric Points ◽  
Cytosolic Glutathione ◽  
Lung And Kidney

Six GSH transferases with neutral/acidic isoelectric points were purified from the cytosol fraction of rat liver. Four transferases are class Mu enzymes related to the previously characterized GSH transferases 3-3, 4-4 and 6-6, as judged by structural and enzymic properties. Two additional GSH transferases are distinguished by high specific activities with 4-hydroxyalk-2-enals, toxic products of lipid peroxidation. The most abundant of these two enzymes, GSH transferase 8-8, a class Alpha enzyme, has earlier been identified in rat lung and kidney. The amino acid sequence of subunit 8 was determined and showed a typical class Alpha GSH transferase structure including an N-acetylated N-terminal methionine residue.

scholarly journals Kinetic independence of the subunits of cytosolic glutathione transferase from the rat

1985 ◽  
Vol 231 (2) ◽  
pp. 263-267 ◽  
Author(s):  
U H Danielson ◽  
B Mannervik
Keyword(s):  
Glutathione Transferase ◽  
Ethacrynic Acid ◽  
Glutathione Transferases ◽  
Kinetic Properties ◽  
Subunit Interactions ◽  
Steady State Kinetics ◽  
Binding Isotherms ◽  
Cytosolic Glutathione ◽  
Kinetics Of ◽  
Rate Behaviour

The steady-state kinetics of the dimeric glutathione transferases deviate from Michaelis-Menten kinetics, but have hyperbolic binding isotherms for substrates and products of the enzymic reaction. The possibility of subunit interactions during catalysis as an explanation for the rate behaviour was investigated by use of rat isoenzymes composed of subunits 1, 2, 3 and 4, which have distinct substrate specificities. The kinetic parameter kcat./Km was determined with 1-chloro-2,4-dinitrobenzene, 4-hydroxyalk-2-enals, ethacrynic acid and trans-4-phenylbut-3-en-2-one as electrophilic substrates for six isoenzymes: rat glutathione transferases 1-1, 1-2, 2-2, 3-3, 3-4 and 4-4. It was found that the kcat./Km values for the heterodimeric transferases 1-2 and 3-4 could be predicted from the kcat./Km values of the corresponding homodimers. Likewise, the initial velocities determined with transferases 3-3, 3-4 and 4-4 at different degrees of saturation with glutathione and 1-chloro-2,4-dinitrobenzene demonstrated that the kinetic properties of the subunits are additive. These results show that the subunits of glutathione transferase are kinetically independent.

scholarly journals Altered glutathione transferase levels in rat skin inflamed due to contact hypersensitivity: induction of the Alpha-class subunit 1

1998 ◽  
Vol 335 (3) ◽  
pp. 605-610 ◽  
Author(s):  
Junya KIMURA ◽  
Makoto HAYAKARI ◽  
Takayuki KUMANO ◽  
Hajime NAKANO ◽  
Kimihiko SATOH ◽  
...  
Keyword(s):  
Glutathione Transferase ◽  
Specific Activity ◽  
Contact Hypersensitivity ◽  
Glutathione Transferases ◽  
Rat Skin ◽  
Enzyme Modification ◽  
Control Value ◽  
Control Skin ◽  
Gst Activity

Since glutathione transferases (GSTs) are suggested to be involved in the prevention of tissue damage by oxidative stress, quantitative and qualitative alterations of GST forms were examined in rat skin after induction of inflammation by 0.6 and 1% 1-chloro-2,4-dinitrobenzene (CDNB) treatment. With 0.6% CDNB, the GST activity in supernatant preparations was 1.8-fold higher than that for control skin, with most GSTs in both cases being bound to S-hexyl-GSH–Sepharose. Major GST subunits of control skin were identified as subunits 7, 4 and 2 by HPLC and chromatofocusing at pH 11–7. These subunits were increased in inflamed skin by 0.6% CDNB and, in addition, the subunit 1 of the Alpha class and subunit 6, both hardly detectable in control skin, were expressed. The specific activity value for GST 7-7 from the inflamed skin by 0.6% CDNB was 2.4-fold lower than that from control skin. However, in the case of inflamed skin after application of 1% CDNB, GST activity was decreased to 69% of the control value and most activity was recovered in fractions binding to a GSH–Sepharose but not a S-hexyl-GSH–Sepharose column. GSTs eluted from the former column demonstrated a restored capacity to bind to the latter, suggesting the GSTs in inflamed skin to be partly inactivated and that they regained activity on exposure to GSH. The Km and Vmax values for GSH of GST 4-4 from inflamed skin after 1% CDNB treatment were 6-fold and 2-fold higher, respectively, than those for the enzyme from control skin, suggesting partial enzyme modification. These results suggest that not only quantitative but also qualitative alterations of GST subunits occur with CDNB-induced inflammation in vivo.

scholarly journals Increase in the amount of glutathione transferase 4-4 in the rat adrenal gland after hypophysectomy and down-regulation by subsequent treatment with adrenocorticotrophic hormone

1990 ◽  
Vol 265 (1) ◽  
pp. 147-154 ◽  
Author(s):  
L Mankowitz ◽  
V M Castro ◽  
B Mannervik ◽  
J Rydström ◽  
J W DePierre
Keyword(s):  
Adrenal Gland ◽  
Adrenocorticotropic Hormone ◽  
Glutathione Transferase ◽  
Fold Increase ◽  
Subsequent Treatment ◽  
Glutathione Transferases ◽  
Pituitary Hormone ◽  
Down Regulation ◽  
Trans Stilbene ◽  
Hypophysectomized Rats

The effect of hypophysectomy and subsequent treatment with adrenocorticotropic hormone (adrenocorticotropin, ACTH) on the isoenzymes of glutathione transferase in the rat adrenal gland was investigated. A large increase (approx. 11-fold) in the level of transferase subunit 4 was observed in hypophysectomized animals by immunoblotting. When the activity of glutathione transferase 4-4 was measured in adrenal cytosol using trans-stilbene oxide as a selective substrate, a 15-fold increase was noted. Lack of the pituitary hormone ACTH is apparently related to this increase, since treatment of hypophysectomized animals with ACTH for 2 weeks partially down-regulated subunit 4. Glutathione transferase subunits 3 and 8 in the adrenal were also increased in amount by hypophysectomy, but not at all to the same extent. The activity of glutathione transferase 4-4 was elevated also in the liver and ovary (5 and 1.5 times respectively) after hypophysectomy. These elevated enzyme levels were, however, not affected by ACTH treatment. This down-regulation of glutathione transferases in the rat adrenal by ACTH may be related to the fact that, under normal conditions, this organ is highly susceptible to the toxic effects of various polycyclic hydrocarbons, whereas under circumstances where there is no ACTH production, as in hypophysectomized rats, the adrenal is resistant to these same hydrocarbons.

scholarly journals Structure-activity relationships of 4-hydroxyalkenals in the conjugation catalysed by mammalian glutathione transferases

1987 ◽  
Vol 247 (3) ◽  
pp. 707-713 ◽  
Author(s):  
U H Danielson ◽  
H Esterbauer ◽  
B Mannervik
Keyword(s):  
Chain Length ◽  
Active Site ◽  
Glutathione Transferase ◽  
Physiological Role ◽  
Catalytic Efficiency ◽  
Glutathione Transferases ◽  
Side Chain ◽  
Structure Activity ◽  
Cytosolic Glutathione ◽  
Free Energy Of Binding

The substrate specificities of 15 cytosolic glutathione transferases from rat, mouse and man have been explored by use of a homologous series of 4-hydroxyalkenals, extending from 4-hydroxypentenal to 4-hydroxypentadecenal. Rat glutathione transferase 8-8 is exceptionally active with the whole range of 4-hydroxyalkenals, from C5 to C15. Rat transferase 1-1, although more than 10-fold less efficient than transferase 8-8, is the second most active transferase with the longest chain length substrates. Other enzyme forms showing high activities with these substrates are rat transferase 4-4 and human transferase mu. The specificity constants, kcat./Km, for the various enzymes have been determined with the 4-hydroxyalkenals. From these constants the incremental Gibbs free energy of binding to the enzyme has been calculated for the homologous substrates. The enzymes responded differently to changes in the length of the hydrocarbon side chain and could be divided into three groups. All glutathione transferases displayed increased binding energy in response to increased hydrophobicity of the substrate. For some of the enzymes, steric limitations of the active site appear to counteract the increase in binding strength afforded by increased chain length of the substrate. Comparison of the activities with 4-hydroxyalkenals and other activated alkenes provides information about the active-site properties of certain glutathione transferases. The results show that the ensemble of glutathione transferases in a given species may serve an important physiological role in the conjugation of the whole range of 4-hydroxyalkenals. In view of its high catalytic efficiency with all the homologues, rat glutathione transferase 8-8 appears to have evolved specifically to serve in the detoxication of these reactive compounds of oxidative metabolism.

scholarly journals Compensation of Mutation in Arabidopsis glutathione transferase (AtGSTU) Genes under Control or Salt Stress Conditions

2020 ◽  
Vol 21 (7) ◽  
pp. 2349 ◽  
Author(s):  
Edit Horváth ◽  
Krisztina Bela ◽  
Ágnes Gallé ◽  
Riyazuddin Riyazuddin ◽  
Gábor Csomor ◽  
...  
Keyword(s):  
Salt Stress ◽  
Glutathione Transferase ◽  
Redox Homeostasis ◽  
Redox Status ◽  
Glutathione Transferases ◽  
Wild Type ◽  
General Role ◽  
First Time ◽  
Gst Activity

Glutathione transferases (GSTs) play a crucial role in detoxification processes due to the fact of their glutathione (GSH) conjugating activity, and through glutathione peroxidase or dehydroascorbate reductase (DHAR) activities, they influence the redox state of GSH and ascorbate (AsA). The plant-specific tau (GSTU) group is the largest class of Arabidopsis GSTs, and their members are involved in responses to different abiotic stresses. We investigated the effect of salt stress on two-week-old Arabidopsis thaliana wild-type (Col-0), Atgstu19 and Atgstu24 mutant plants after applying 150 mM NaCl for two days. The Atgstu19 seedlings had lower GST activity and vitality both under control conditions and after salt stress than the wild-type, but the level of total ROS was similar to the Col-0 plants. The GST activity of the knockout Atgstu24 mutant was even higher under control conditions compared to the Col-0 plants, while the ROS level and its vitality did not differ significantly from the wild-type. Analysis of the AtGSTU expression pattern revealed that the mutation in a single AtGSTU gene was accompanied by the up- and downregulation of several other AtGSTUs. Moreover, elevated AsA and GSH levels, an altered GSH redox potential and increased DHAR and glutathione reductase activities could help to compensate for the mutation of AtGSTU genes. The observed changes in the mutants suggest that the investigated isoenzymes influence the redox homeostasis under control conditions and after NaCl treatment in Arabidopsis seedlings. These data indicate for the first time the more general role of a temporary shift of redox status as part of GST mechanisms and regulation.

Chemoprotective Effects of Propolis on Aflatoxin B1-Induced Hepatotoxicity in Rats: Oxidative Damage and Hepatotoxicity by Modulating TP53, Oxidative Stress

2020 ◽  
Vol 17 (3) ◽  
pp. 191-199
Author(s):  
Seval Yilmaz ◽  
Fatih Mehmet Kandemir ◽  
Emre Kaya ◽  
Mustafa Ozkaraca
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Oxidative Damage ◽  
Aflatoxin B1 ◽  
Tp53 Gene ◽  
Control Group ◽  
Glutathione S Transferase ◽  
Gene Expressions ◽  
Cat Gene ◽  
Gst Activity

Objective: This study aimed to detect hepatic oxidative damage caused by aflatoxin B1 (AFB1), as well as to examine how propolis protects against hepatotoxic effects of AFB1. Method: Rats were split into four groups as control group, AFB1 group, propolis group, AFB1+ propolis group. Results: There was significant increase in malondialdehyde (MDA) level and tumor suppressor protein (TP53) gene expression, Glutathione (GSH) level, Catalase (CAT) activity, CAT gene expression decreased in AFB1 group in blood. MDA level and Glutathione-S-Transferase (GST) activity, GST and TP53 gene expressions increased in AFB1 group, whereas GSH level and CAT activity alongside CAT gene expression decreased in liver. AFB1+propolis group showed significant decrease in MDA level, GST activity, TP53 and GST gene expressions, GSH level and CAT activity and CAT gene expression increased in liver compared to AFB1 group. Conclusion: These results suggest that propolis may potentially be natural agent that prevents AFB1- induced oxidative stress and hepatotoxicity.

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