3 Phospholipid hydroperoxide glutathione peroxidase activity of rat class Theta glutathione transferase T2-2

1997 ◽  
Vol 25 (4) ◽  
pp. S559-S559 ◽  
Author(s):  
RACHEL HURST ◽  
YONGPING BAO ◽  
PER JEMTH ◽  
BENGT MANNERVIK ◽  
GARY WILLIAMSON
Keyword(s):  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Glutathione Transferase ◽  
Phospholipid Hydroperoxide Glutathione Peroxidase ◽  
Glutathione Peroxidase Activity ◽  
Phospholipid Hydroperoxide

scholarly journals Phospholipid hydroperoxide glutathione peroxidase activity of human glutathione transferases

1998 ◽  
Vol 332 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Rachel HURST ◽  
Yongping BAO ◽  
Per JEMTH ◽  
Bengt MANNERVIK ◽  
Gary WILLIAMSON
Keyword(s):  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Hplc Method ◽  
Glutathione Transferases ◽  
Phospholipid Hydroperoxide Glutathione Peroxidase ◽  
Glutathione Peroxidase Activity ◽  
Phospholipid Hydroperoxide ◽  
Hydrophobic Site ◽  
Hydrophobic Binding ◽  
Specific Activities

Human glutathione transferases (GSTs) from Alpha (A), Mu (M) and Theta (T) classes exhibited glutathione peroxidase activity towards phospholipid hydroperoxide. The specific activities are in the order: GST A1-1 > GST T1-1 > GST M1-1 > GST A2-2 > GST A4-4. Using a specific and sensitive HPLC method, specific activities towards the phospholipid hydroperoxide, 1-palmitoyl-2-(13-hydroperoxy-cis-9, trans-11-octadecadienoyl)-l-3-phosphatidylcholine (PLPC-OOH) were determined to be in the range of 0.8–20 nmol/min per mg of protein. Two human class Pi (P) enzymes (GST P1-1 with Ile or Val at position 105) displayed no activity towards the phospholipid hydroperoxide. Michaelis–Menten kinetics were followed only for glutathione, whereas there was a linear dependence of rate with PLPC-OOH concentration. Unlike the selenium-dependent phospholipid hydroperoxide glutathione peroxidase (Se-PHGPx), the presence of detergent inhibited the activity of GST A1-1 on PLPC-OOH. Also, in contrast with Se-PHGPx, only glutathione could act as the reducing agent for GST A1-1. A GST A1-1 mutant (Arg15Lys), which retains the positive charge between the GSH- and hydrophobic binding sites, exhibited a decreased kcat for PLPC-OOH but not for CDNB, suggesting that the correct topography of the GSH site is more critical for the phospholipid substrate. A Met208Ala mutation, which gives a modified hydrophobic site, decreased the kcat for CDNB and PLPC-OOH by comparable amounts. These results indicate that Alpha, Mu and Theta class human GSTs provide protection against accumulation of cellular phospholipid hydroperoxides.

scholarly journals Glutathione system in rat blood serum under the conditions of carrageenan-induced joint inflammation and chondroitin sulfate prophylactic injection

2021 ◽  
Vol 85 (2) ◽  
pp. 32-37
Author(s):  
K. Dvorshchenko ◽  
O. Korotkiy ◽  
D. Grebinyk ◽  
Ye. Torgalo
Keyword(s):  
Glutathione Peroxidase ◽  
Chondroitin Sulfate ◽  
Peroxidase Activity ◽  
Glutathione Transferase ◽  
Reduced Glutathione ◽  
Joint Inflammation ◽  
Transferase Activity ◽  
Glutathione System ◽  
Nacl Solution ◽  
Glutathione Peroxidase Activity

The goal of this work was the research of chondroitin sulfate prophylactic action on the glutathione system state in rat blood serum during acute joint inflammation. The research was performed on white non-linear pubertal rat males weighting 160-240 grams in compliance to all general ethical principles of animal research. All animals were divided to four experimental groups. The first group – the control: the animals were injected with 0,1 ml of 0,9 % NaCl solution in a right hind leg. The second group – rats were subjected to daily intramuscular injections of 3 mg/kg of chondroitin sulfate in the theurapeutic dose during 28 days. The third group – the animals were subjected to daily doses of 0,1 ml of 0,9 % NaCl solution injected in right hind extremities and starting from 29th day the acute joint inflammation was modelled (the animals were subjected to 0,1 ml of 1% of сarrageenan intramuscular injection in right hind extremities. The fourth group – rats were receiving intramuscular injections of therapeutic dose of 3 mg/kg of chondroitin sulfate for 28 days, and after that the acute joint inflammation was modelled starting from 29th day. 40 animals in all were taking part in the experimental research. The glutathione peroxidase activity was assessed judging from the decrease in GSH amount in the reaction with Ellman reagent. The glutathione peroxidase activity was estimated by the decrease in probe optical density owing to NADPH oxidation. Glutathione transferase activity was estimated by the speed of the conjugate formation between GSH and 1-chloro-2,4-dinitrobemzene. The amount of reduced glutathione was estimated spectrophotometrically using orthophthalic aldehyde. It was established that during the carrageenan-induced inflammation the glutathione peroxidase, glutathione reductase and glutathione reductase activity were reduced, a well as the amount of reduced glutathione, whereas the glutathione transferase activity was increased in comparison to the control. It was shown that under the prophylactic injection of the chondroitin sulfate based preparate to animals with acute joint inflammation the aforementioned parameters were partially stabilized.

scholarly journals Basic components of glutathion system in rat erythrocytes under conditions of toxic damage on the background of an alimental protein lack

2020 ◽  
Vol 12 (1) ◽  
pp. 31-38
Author(s):  
Halyna Kopylchuk ◽  
Ivanna Nykolaichuk
Keyword(s):  
Glutathione Peroxidase ◽  
Glutathione Reductase ◽  
Peroxidase Activity ◽  
Glutathione Transferase ◽  
Reduced Glutathione ◽  
Oxidized Glutathione ◽  
Glutathione Peroxidase Activity ◽  
Rat Erythrocytes ◽  
Toxic Damage ◽  
Glucose 6 Phosphate Dehydrogenase

The article is devoted to the study of the main components of the glutathione system under conditions of toxic damage against the background of nutritional protein deficiency: the content of reduced and oxidized glutathione with the determination of the GSH/GSSG ratio, the activity of glutathione-dependent enzymes – glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase. The concentration of reduced glutathione in the erythrocyte hemolysate was studied using Elman's reagent after deproteinization of the samples. Glutathione transferase activity was determined by the rate of formation of glutathione S conjugates by reacting reduced glutathione with a substrate of 1-chloro-2.4-dinitrobenzene. Glutathione peroxidase activity was evaluated by the formation of oxidized glutathione. The activity of glutathione reductase in erythrocytes was determined by the method, is based on measuring the oxidation rate of NADPH+H+, which is recorded by decreasing absorption at a wavelength of 340 nm. A decrease in the ratio of GSH/GSSG in rat erythrocytes under conditions of toxic damage against a nutritional deficiency of protein is indicated by a functional shift in the thiol-disulfide balance towards increased use of the reduced form of glutathione for antioxidant protection. It was established that toxic damage is a key factor in reducing the level of glutathione transferase against the background of an increase in glutathione peroxidase activity in rat erythrocytes, the activation of which probably prevents the progression of LPO processes. At the same time, under conditions of toxic damage, against the background of alimentary protein deficiency, a decrease in glutathione reductase and glucose-6-phosphate dehydrogenase activity is observed, which leads to blocking of the first stage of glucose-6-phosphate metabolism in the pentose phosphate cycle, resulting in a decrease in the amount of NADPH and, accordingly reduced glutathione.

Low Selenium Status in the Elderly Influences Thyroid Hormones

1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Thyroid Hormones ◽  
Peroxidase Activity ◽  
Controlled Trial ◽  
The Elderly ◽  
Serum Selenium ◽  
Selenium Status ◽  
Glutathione Peroxidase Activity ◽  
Double Blind ◽  
Double Blind Placebo

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.

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