scholarly journals The glutathione S-transferases in selenium and vitamin E deficiency

1985 ◽  
Vol 227 (3) ◽  
pp. 823-831 ◽  
Author(s):  
A Mehlert ◽  
A T Diplock
Keyword(s):  
Vitamin E ◽  
Time Course ◽  
Gel Filtration ◽  
Selenium Deficiency ◽  
Total Activity ◽  
Supernatant Fraction ◽  
Glutathione S Transferase ◽  
Vitamin E Deficiency ◽  
Glutathione S Transferases ◽  
Two Peaks

Preliminary experiments confirmed the work of others showing that the total glutathione peroxidase (GSH-px) activity of rat liver supernatant fraction may be resolved into two peaks of activity (peaks I and II) by gel filtration, and that peak I is the selenium-containing enzyme and peak II is another peroxidase indistinguishable from glutathione S-transferase (GST). In selenium and vitamin E deficiency, the total activity of the GSH-px became very low, and the total activity of GST with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate was enhanced. Study of the time course of these changes as deficiency progressed indicated that the stimulus for the rise in GST (CDNB) activity was the fall in GSH-px activity which preceded it. The peroxidase activity of GST was found to reside only in the GST AA, B and B2 forms of the enzyme, which were shown to be respectively a homodimer of the Yc subunit, a homodimer of the Ya subunit and a heterodimer of the YaYc subunit. As vitamin E and selenium deficiency progressed, the B2 and AA forms of the enzyme showed enhanced activity, which was interpreted as implying that the Yc subunit of the enzyme becomes enriched as a consequence of the withdrawal of selenium from the animal's diet. Densitometric measurements of the Yc and Ya subunits confirmed that the amount of the Yc subunit was nearly doubled in selenium deficiency, relative to the Ya subunit.

scholarly journals Glutathione S-transferases from the white-rot fungus, Phanerochaete chrysosporium

1997 ◽  
Vol 324 (1) ◽  
pp. 243-248 ◽  
Author(s):  
Caitriona A. DOWD ◽  
Catherine M. BUCKLEY ◽  
David SHEEHAN
Keyword(s):  
Molecular Mass ◽  
Phanerochaete Chrysosporium ◽  
Sequence Similarity ◽  
Gel Filtration ◽  
Preliminary Evidence ◽  
White Rot ◽  
White Rot Fungus ◽  
Glutathione S Transferase ◽  
Glutathione S Transferases ◽  
A Subunit

A glutathione S-transferase (GST) was purified to homogeneity from the white-rot fungus, Phanerochaete chrysosporium, by affinity chromatography on glutathione–agarose followed by Mono-Q ion-exchange FPLC. This protein immunoblotted with antisera to rat Theta class GST 5-5 and also showed N-terminal sequence similarity to the Theta class, including the presence of a conserved serine residue that has been specifically implicated in catalysis in this class [Wilce, Board, Feil and Parker (1995) EMBO J. 14, 2133–2143] and other residues conserved in plant sequences. Catalytic activity was found to be highly labile in the purified protein, although preliminary evidence for activity (approx. 120 m-units/mg) with 1,2-epoxy-3-(p-nitrophenoxy)propane was obtained in some preparations. The enzyme seems to be a dimer with a subunit molecular mass of 25 kDa by SDS/PAGE. The native molecular masses estimated by non-denaturing electrophoresis and by Superose-12 gel filtration were 58 and 45 kDa respectively. A second protein purified in this study also gave low level of activity with 1,2-epoxy-3-(p-nitrophenoxy)propane and had a subunit molecular mass of 28 kDa (native size 62–63 kDa), but did not immunoblot with any GST class and seemed to be N-terminally blocked.

Effect of inhibitors of glutathione S-transferase on glyceryl trinitrate activity in isolated rat aorta

1993 ◽  
Vol 71 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Rita Nigam ◽  
Tracy Whiting ◽  
Brian M. Bennett
Keyword(s):  
Glyceryl Trinitrate ◽  
Cyclic Gmp ◽  
Guanylyl Cyclase ◽  
Rat Aorta ◽  
Supernatant Fraction ◽  
Organic Nitrates ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Glutathione S Transferases

We investigated the role of glutathione S-transferases (enzymes known to biotransform organic nitrates) in the vascular action of glyceryl trinitrate (GTN). Relaxation of phenylephrine-contracted rat aortic strips was assessed in the presence or absence of the glutathione S-transferase inhibitors Basilen Blue, bromosulfophthalein, Rose Bengal, hematin, chlorotriphenyltin, and (octyloxy)benzoylvinylglutathione. Whereas none of the inhibitors increased the EC50 for GTN relaxation, glutathione S-transferase activity in the 100 000 × g supernatant fraction of rat aorta was inhibited markedly by most of the inhibitors. In addition, GTN-stimulated activation of aortic guanylyl cyclase in broken-cell preparations was attenuated by all of the glutathione S-transferase inhibitors, suggesting a direct inhibitory action on guanylyl cyclase. In other experiments using aortic strips preexposed to phenylephrine, the inhibitors had no effect on GTN-induced cyclic GMP accumulation or on vascular biotransformation of GTN. In contrast, both Basilen Blue and bromosulfophthalein significantly inhibited GTN-induced relaxation of K+-contracted aortic strips, and Basilen Blue significantly inhibited GTN biotransformation in aortic strips preexposed to 25 mM K+. This may be due to a more favourable electrochemical gradient for entry of the inhibitors into membrane-depolarized tissues. We conclude that vascular glutathione S-transferases play a role in mediating the vasodilator actions of GTN in intact tissues in vitro, but that this appears to depend upon the nature of the contractile agent used in such studies.Key words: glyceryl trinitrate, glutathione S-transferase, cyclic GMP, vascular smooth muscle, biotransformation.

scholarly journals Selenium deficiency activates mouse liver Nrf2–ARE but vitamin E deficiency does not

2008 ◽  
Vol 44 (8) ◽  
pp. 1617-1623 ◽  
Author(s):  
Raymond F. Burk ◽  
Kristina E. Hill ◽  
Akihiro Nakayama ◽  
Volker Mostert ◽  
Ximena A. Levander ◽  
...  
Keyword(s):  
Vitamin E ◽  
Mouse Liver ◽  
Selenium Deficiency ◽  
Vitamin E Deficiency

scholarly journals Plasmin Inhibitors in Human Urine

1977 ◽  
Author(s):  
H. Sumi ◽  
Y. Takada ◽  
A. Takada
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Molecular Form ◽  
Membrane Filter ◽  
Gel Filtration ◽  
Total Activity ◽  
Native Form ◽  
Molecular Weights ◽  
Two Peaks

By the gel filtration of urinary protein on Sephadex G-200, two peaks of activity to hydrolyze Nα-acetylglycyl-L-lysine methyl ester (AGLMe) were detected. One was the native form of urokinase, and the molecular weight was about 54,000. The other was of high molecular weight, and eluted in void fraction. The high molecular form was thought to be a complex of urokinase and urinary plasmin inhibitor (UPI). By using Arg-Sepharose, membrane filter (M.W. 10,000), and pevikon block electrophoresis, we could isolate four types of UPI from normal human urine. One UPI was positively charged at pH 8.6, and of high molecular weight. Other types were negatively charged, and the molecular weights by gel filtration on Sephadex G-200 were about 67,000 (UPI6.7), 45,000 (UPI4.5), and 22, 000 (UPI2.2), respectively. In acrylamide disc gel electrophoresis, UPI57 migrated to serum prealbumin fraction, and UPI45 and UPI? 2 were less anionic. Negative-charged UPIs could be adsorbed on trypsin-Sepharose, and were thought to be identical to urinary trypsin inhibitors. Purified UPIs showed strong inhibition on caseinolytic- and esterolytic-activities of plasmin, and the total activity was about 16 UPIU(inhibited 16 casein U of plasmin)/liter of urine.

6.3 The Development and Effects of Selenium Deficiency

1983 ◽  
Vol 7 ◽  
pp. 128-128
Author(s):  
J. R. Arthur ◽  
R. Boyne
Keyword(s):  
Skeletal Muscle ◽  
Vitamin E ◽  
Glutathione Peroxidase ◽  
Heart Muscle ◽  
Clinical Symptoms ◽  
Selenium Deficiency ◽  
Focal Lesions ◽  
Vitamin E Deficiency ◽  
Vitamin E Status ◽  
Cattle And Sheep

Deficiencies of selenium (Se) and vitamin E can result in myopathies in cattle and sheep but the mechanics have not been clearly described. Both Se, as a component of the enzyme glutathione peroxidase, and vitamin E as a radicle scavenger, are involved in the protection of cells against the toxic effects of oxygen. In young calves, Se/vitamin E deficiency can result in the death of the animals due to a focal myopathy occurring in heart muscle; focal lesions are also found in skeletal muscle. In older calves, a more diffuse myopathy is usually confined to skeletal muscle and usually occurs when cattle are turned out from winter housing to spring pasture. However, low Se/vitamin E status will not invariably result in clinical symptoms of myopathy and other factors may be involved. This report describes some of the biochemical changes which can occur during the onset of clinical myopathy in Se/vitamin E-deficient cattle.

scholarly journals Comparison of renal and hepatic glutathione S-transferases in the rat

1976 ◽  
Vol 158 (2) ◽  
pp. 243-248 ◽  
Author(s):  
N Kaplowitz ◽  
G Clifton ◽  
J Kuhlenkamp ◽  
J D Wallin
Keyword(s):  
Organic Anion ◽  
Gel Filtration ◽  
Competitive Inhibitor ◽  
Transferase Activity ◽  
Close Correspondence ◽  
Glutathione S Transferase ◽  
Competitive Inhibitors ◽  
Liver And Kidney ◽  
Glutathione S Transferases

Renal and hepatic GSH (reduced glutathione) S-transferase were compared with respect to substrate and inhibitory kinetics and hormonal influences in vivo. An example of each of five classes of substrates (aryl, aralkyl, epoxide, alkyl and alkene) was used. In the gel filtration of renal or hepatic cytosol, an identical elution volume was found for all the transferase activities. Close correspondence in Km values was found for aryl, epoxide- and alkyl-transferase activities, with only the aralkyl activity significantly lower in kidney. Probenecid and p-aminohippurate were competitive inhibitors of renal aryl-, aralkyl-, epoxide- and alkyl-transferase activities and inhibited renal alkene activity. Close correspondence in Ki values for inhibition by probenecid of these activities in kidney and liver was found. In addition, furosemide was a potent competitive inhibitor of renal alkyl-transferase activity. Hypophysectomy resulted in significant increases in aryl-, araklyl-, and expoxide-transferase activities in liver and kidney. The hypophysectomy-induced increases in renal aryl- and aralkyl-transferase activities (approx. 100%) were more than twofold greater than increases in hepatic activities (approx. 40%). Administration of thyroxine prevented the hypophysectomy-induced increase in aryltransferase activity in both kidney and liver. The renal GSH S-transferases, in view of similarities to the hepatic activities, may play a role as cytoplasmic organic-anion receptors, as previously proposed for the hepatic enzymes.

scholarly journals Glutathione S-transferases in elasmobranch liver. Molecular heterogeneity, catalytic and binding properties, and purification

1981 ◽  
Vol 199 (3) ◽  
pp. 749-756 ◽  
Author(s):  
Yuichi Sugiyama ◽  
Tadataka Yamada ◽  
Neil Kaplowitz
Keyword(s):  
Enzyme Activity ◽  
Rose Bengal ◽  
Organic Anion ◽  
Gel Filtration ◽  
Anion Binding ◽  
Molecular Heterogeneity ◽  
Glutathione S Transferase ◽  
Binding Studies ◽  
Binding Properties ◽  
Glutathione S Transferases

In order to gain insight into the phylogeny and physiological significance of organic-anion-binding proteins in the liver, the hepatic glutathione S-transferases of rat and a typical elasmobranch, the thorny-back shark (Platyrhinoides triseriata), were compared with respect to both glutathione S-transferase activites and organic-anion-binding properties. On gel filtration (Sephadex G-75, Superfine grade) of rat cytosol, the elution volumes of enzyme activities with 1-chloro-2,4-dinitrobenzene and p-nitrobenzyl chloride as substrates were identical (rat Y-fractions; Mr 45000). In contrast, two peaks of enzyme activity for 1-chloro-2,4-dinitrobenzene with elution volumes corresponding to Mr 52000 (PLAT Y1) and Mr 45000 (PLAT Y2) were detected on gel filtration of P. triseriata cytosol. Only fraction PLAT Y2 had enzyme activity with p-nitrobenzyl chloride. Enzyme kinetic studies showed that rat Y-fraction had higher affinities for both 1-chloro-2,4-dinitrobenzene and glutathione than PLAT Y1- and PLAT Y2-fractions. The two forms of P. triseriata glutathione S-transferases differed greatly in affinity for glutathione. At a glutathione concentration that we found to be physiological in P. triseriata, PLAT Y2 accounted for approx. 70% of the total glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene. Binding studies revealed that PLAT Y1 and PLAT Y2 fractions had much lower affinities for sulphobromophthalein and bilirubin than rat Y-fraction. In contrast, binding affinities of PLAT Y1 and PLAT Y2 for Rose Bengal and 1-anilino-8-naphthalenesulphonate were comparable with that of rat Y-fraction. Inhibitory kinetics suggested that sulphobromophthalein and Rose Bengal were non-competitive inhibitors of glutathione S-transferase activities when 1-chloro-2,4-dinitrobenzene was used as substrate for both PLAT Y1 and PLAT Y2. The major glutathione S-transferase from the PLAT Y2 fraction was purified 81-fold by sequential chromatography on Sephadex G-75, DEAE-Sephadex and hydroxyapatite, and consisted of two identical subunits with pI7.7. The highly enriched Y2-fraction retained high affinity binding of Rose Bengal and 1-anilino-8-naphthalenesulphonate.

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 Selenium Deficiency, but Not Vitamin E Deficiency, Activates the Mouse Liver Nrf2‐ARE Pathway

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Raymond F Burk ◽  
Kristina E Hill ◽  
Akihiro Nakayama ◽  
Volker Mostert ◽  
Ximena A Levander ◽  
...  
Keyword(s):  
Vitamin E ◽  
Mouse Liver ◽  
Selenium Deficiency ◽  
Vitamin E Deficiency
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