scholarly journals Characterization of the basic glutathione S-transferase B1 and B2 subunits from human liver

1987 ◽  
Vol 244 (1) ◽  
pp. 55-61 ◽  
Author(s):  
P K Stockman ◽  
L I McLellan ◽  
J D Hayes
Keyword(s):  
Glutathione Peroxidase ◽  
Human Liver ◽  
Catalytic Properties ◽  
Peptide Mapping ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Tryptic Peptides ◽  
Glutathione S Transferases ◽  
Tributyltin Acetate

The basic glutathione S-transferases in human liver are composed of at least two immunochemically distinct polypeptides, designated B1 and B2. These subunits exist as homodimers, but can hybridize to form the B1B2 heterodimer [Stockman, Beckett & Hayes (1985) Biochem. J. 227, 457-465]. Although these basic glutathione S-transferases possess similar catalytic properties, the B2 subunit exhibits significantly greater selenium-independent glutathione peroxidase activity than subunit B1. The use of the ligands haematin, tributyltin acetate and Bromosulphophthalein as inhibitors of 1-chloro-2,4-dinitrobenzene-GSH-conjugating activity clearly discriminate between the B1 and B2 subunits and should help facilitate their identification. Peptide mapping experiments showed that B1 and B2 are structurally distinct, but related, subunits; subunit B1 yielded 43 tryptic peptides, seven of which were unique, whereas subunit B2 yielded 40 tryptic peptides, four of which were unique.

scholarly journals Glutathione S-transferases of human brain. Evidence for two immunologically distinct types of 26500-Mr subunits

1985 ◽  
Vol 225 (2) ◽  
pp. 375-382 ◽  
Author(s):  
C Theodore ◽  
S V Singh ◽  
T D Hong ◽  
Y C Awasthi
Keyword(s):  
Human Brain ◽  
Gel Electrophoresis ◽  
Human Liver ◽  
Catalytic Properties ◽  
Anionic Form ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Cationic Form ◽  
Two Dimensional Gel Electrophoresis ◽  
Glutathione S Transferases

Human brain contains one cationic (pI8.3) and two anionic (pI5.5 and 4.6) forms of glutathione S-transferase. The cationic form (pI8.3) and the less-anionic form (pI5.5) do not correspond to any of the glutathione S-transferases previously characterized in human tissues. Both of these forms are dimers of 26500-Mr subunits; however, immunological and catalytic properties indicate that these two enzyme forms are different from each other. The cationic form (pI8.3) cross-reacts with antibodies raised against cationic glutathione S-transferases of human liver, whereas the anionic form (pI5.5) does not. Additionally, only the cationic form expresses glutathione peroxidase activity. The other anionic form (pI4.6) is a dimer of 24500-Mr and 22500-Mr subunits. Two-dimensional gel electrophoresis demonstrates that there are three types of 26500-Mr subunits, two types of 24500-Mr subunits and two types of 22500-Mr subunits present in the glutathione S-transferases of human brain.

scholarly journals Glutathione S-transferases of the bovine retina. Evidence that glutathione peroxidase activity is the result of glutathione S-transferase

1982 ◽  
Vol 205 (1) ◽  
pp. 213-217 ◽  
Author(s):  
R P Saneto ◽  
Y C Awasthi ◽  
S K Srivastava
Keyword(s):  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Structural Parameters ◽  
Gel Filtration ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Ph Optimum ◽  
Bovine Retina ◽  
Apparent Homogeneity ◽  
Glutathione S Transferases

We have purified two isoenzymes of glutathione S-transferase from bovine retina to apparent homogeneity through a combination of gel-filtration chromatography, affinity chromatography and isoelectric focusing. The more anionic (pI = 6.34) and less anionic (pI = 6.87) isoenzymes were comparable with respect to kinetic and structural parameters. The Km for both substrates, reduced glutathione and 1-chloro-2,4-dinitrobenzene, bilirubin inhibition of glutathione conjugation to 1-chloro-2,4-dinitrobenzene, 1-chloro-2,4-dinitrobenzene inactivation of enzyme activity and molecular weight were similar. However, pH optimum and energy of activation were found to differ considerably. Retina was found to have no selenium-dependent glutathione peroxidase activity. The total glutathione peroxidase activity fractionated with the transferases in the gel-filtration range of mol.wt. 49000 and expressed activity with only organic hydroperoxides as substrate. Only the more anionic isoenzyme expressed both transferase and peroxidase activity.

scholarly journals Two immunologically distinct Yc-type subunits are present in rat lung glutathione S-transferases

1984 ◽  
Vol 224 (1) ◽  
pp. 335-338 ◽  
Author(s):  
S V Singh ◽  
Y C Awasthi
Keyword(s):  
Glutathione Peroxidase ◽  
Rat Liver ◽  
Peroxidase Activity ◽  
Gel Electrophoresis ◽  
Rat Lung ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Two Dimensional Gel Electrophoresis ◽  
Glutathione S Transferases

Two types of 25 000-Mr subunits are present in rat lung glutathione S-transferase I (pI 8.8). These subunits, designated Yc and Yc', are immunologically and functionally distinct from each other. The homodimers YcYc (pI 10.4) and Yc'Yc' (pI 7.6) obtained by hybridization in vitro of the two subunits of glutathione S-transferase I (pI 8.8) were isolated and characterized. Results of these studies indicate that only the Yc subunits express glutathione peroxidase activity and cross-react with the antibodies raised against glutathione S-transferase B (YaYc) or rat liver. The Yc' subunits do not express glutathione peroxidase activity and do not cross-react with the antibodies raised against glutathione S-transferase B of rat liver. The amino acid compositions of these two subunits are also different. These two subunits can also be separated by the two-dimensional gel electrophoresis of glutathione S-transferase I (pI 8.8) of rat lung.

scholarly journals The distribution, induction and isoenzyme profile of glutathione S-transferase and glutathione peroxidase in isolated rat liver parenchymal, Kupffer and endothelial cells

1989 ◽  
Vol 264 (3) ◽  
pp. 737-744 ◽  
Author(s):  
P Steinberg ◽  
H Schramm ◽  
L Schladt ◽  
L W Robertson ◽  
H Thomas ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Glutathione Peroxidase ◽  
Rat Liver ◽  
Peroxidase Activity ◽  
Cell Types ◽  
Transferase Activity ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Liver Parenchymal ◽  
Parenchymal Cells

The distribution and inducibility of cytosolic glutathione S-transferase (EC 2.5.1.18) and glutathione peroxidase (EC 1.11.1.19) activities in rat liver parenchymal, Kupffer and endothelial cells were studied. In untreated rats glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and 4-hydroxynon-2-trans-enal as substrates was 1.7-2.2-fold higher in parenchymal cells than in Kupffer and endothelial cells, whereas total, selenium-dependent and non-selenium-dependent glutathione peroxidase activities were similar in all three cell types. Glutathione S-transferase isoenzymes in parenchymal and non-parenchymal cells isolated from untreated rats were separated by chromatofocusing in an f.p.l.c. system: all glutathione S-transferase isoenzymes observed in the sinusoidal lining cells were also detected in the parenchymal cells, whereas Kupffer and endothelial cells lacked several glutathione S-transferase isoenzymes present in parenchymal cells. At 5 days after administration of Arocolor 1254 glutathione S-transferase activity was only enhanced in parenchymal cells; furthermore, selenium-dependent glutathione peroxidase activity decreased in parenchymal and non-parenchymal cells. At 13 days after a single injection of Aroclor 1254 a strong induction of glutathione S-transferase had taken place in all three cell types, whereas selenium-dependent glutathione peroxidase activity remained unchanged (endothelial cells) or was depressed (parenchymal and Kupffer cells). Hence these results clearly establish that glutathione S-transferase and glutathione peroxidase are differentially regulated in rat liver parenchymal as well as non-parenchymal cells. The presence of glutathione peroxidase and several glutathione S-transferase isoenzymes capable of detoxifying a variety of compounds in Kupffer and endothelial cells might be crucial to protect the liver from damage by potentially hepatotoxic substances.

scholarly journals Purification and characterization of prostaglandin-H E-isomerase, a sigma-class glutathione S-transferase, from Ascaridia galli

1996 ◽  
Vol 313 (1) ◽  
pp. 223-227 ◽  
Author(s):  
David J. MEYER ◽  
Richmond MUIMO ◽  
Michael THOMAS ◽  
David COATES ◽  
R. Elwyn ISAAC
Keyword(s):  
Parasitic Nematode ◽  
Helminth Parasites ◽  
Ascaridia Galli ◽  
Glutathione S Transferase ◽  
Purification And Characterization ◽  
Parasitic Helminths ◽  
Accessory Cells ◽  
Glutathione S Transferases ◽  
Prostaglandin H

Comparison of partial primary sequences of sigma-class glutathione S-transferases (GSH) of parasitic helminths and a GSH-dependent prostaglandin (PG)-H D-isomerase of rat immune accessory cells suggested that some of the helminth enzymes may also be involved in PG biosynthesis [Meyer and Thomas (1995) Biochem. J. 311, 739-742]. A soluble GSH transferase of the parasitic nematode Ascaridia galli has now been purified which shows high activity and specificity in the GSH-dependent isomerization of PGH to PGE, comparable to that of the rat spleen enzyme in its isomerization of PGH to PGD, and similarly stimulates the activity of prostaglandin H synthase. The enzyme subunit is structurally related to the rat spleen enzyme and sigma-class GSH transferases of helminths according to the partial primary sequence. The data support the hypothesis that some sigma-class GSH transferases of helminth parasites are involved in PG biosynthesis which, in the case of PGE, is likely to be associated with the subversion or suppression of host immunity. A PG-H E-isomerase of comparable specificity and activity has not previously been isolated.

scholarly journals Variability of Glutathione S-Transferase α in Human Liver and Plasma

1999 ◽  
Vol 45 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Theo PJ Mulder ◽  
Daniel A Court ◽  
Wilbert HM Peters
Keyword(s):  
Aspartate Aminotransferase ◽  
Alanine Aminotransferase ◽  
Human Liver ◽  
Organ Donors ◽  
Healthy Controls ◽  
Plasma Samples ◽  
Glutathione S Transferase ◽  
Glutathione S Transferases ◽  
The Mean ◽  
Exogenous Compounds

Abstract Background: Glutathione S-transferases are a family of enzymes involved in the binding, transport, and detoxification of a wide variety of endogenous and exogenous compounds. Little information is available about the variability of class α glutathione S-transferases in human liver, where they are highly expressed, or in serum. Methods: Both total class α glutathione S-transferase (GST-α, composed of GSTA1-1, GSTA1-2, and GSTA2-2) as well as GSTA1-1 concentrations were measured by specific and sensitive ELISA in liver cytosols of 35 organ donors and in plasma samples of 350 healthy controls. Results: The mean total GST-α and GSTA1-1 in liver cytosols were 25.1 ± 9.4 and 10.7 ± 5.3 μg/mg protein, respectively, and did not correlate with activities of aspartate aminotransferase or alanine aminotransferase. The mean total GST-α in liver was significantly higher in females compared with males (28.8 ± 10.0 vs 22.0 ± 7.8 μg/mg protein; P <0.05). In contrast, the median total GST-α in plasma was lower in females compared with males (2.0 and 2.8 μg/L, respectively; P <0.0001). The median ratios for GSTA1-1/total GST-α in liver and plasma were 0.42 and 0.58, respectively. Conclusions: GSTA1-1 constitutes approximately one-half of the total amount of α class GSTs in human plasma and liver. Total GST-α values are higher in female liver but lower in plasma compared with the respective values in males.

scholarly journals Characterization of glutathione S-transferases in rat kidney. Alteration of composition by cis-platinum

1988 ◽  
Vol 252 (1) ◽  
pp. 127-136 ◽  
Author(s):  
G M Trakshel ◽  
M D Maines
Keyword(s):  
Specific Activity ◽  
Rat Kidney ◽  
Male Rats ◽  
Glutathione S Transferase ◽  
Aberrant Form ◽  
Glutathione S Transferases ◽  
Exchange Matrix ◽  
Rat Kidney Cytosol

We have developed chromatographic and mathematical protocols that allowed the high resolution of glutathione S-transferase (GST) subunits, and the identification of a previously unresolved GST monomer in rat kidney cytosol; the monomer was identified tentatively as subunit 6. Also, an aberrant form of GST 7-7 dimer appeared to be present in the kidney. This development was utilized to illustrate the response of rat kidney GST following cis-platinum treatment in vivo. Rat kidney cytosol was separated into three ‘affinity families’ of GST activity after elution from a GSH-agarose matrix. The affinity peaks were characterized by quantitative differences in their subunit and dimeric compositions as determined by subsequent chromatography on a cation-exchange matrix and specific activity towards substrates. By use of these criteria, the major GST dimers of affinity peaks were tentatively identified. The major GST dimers in peak I were GST 1-1 and 1-2, in affinity peak II it was GST 2-2, and in peak III they were GST 3-3 and 7-7. GST 3-6 and/or 4-6, which have not been previously resolved in kidney cytosol, were also present in peak II. Alterations in the kidney cytosolic GST composition of male rats were detected subsequent to the administration of cis-platinum (7.0 mg/kg subcutaneously, 6 days). This treatment caused a pronounced alteration in the GST profile, and the pattern of alteration was markedly different from that reported for other chemicals in the kidney or in the liver. In general, the cellular contents of the GSTs of the Alpha and the Mu classes decreased and increased respectively. It is postulated that the decrease in the Alpha class of GSTs by cis-platinum treatment may be related to renal cortical damage and the loss of GSTs in the urine. The increase in the Mu class of GSTs could potentially stem from a lowered serum concentration of testosterone; the latter is a known effect of cis-platinum treatment.

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