Catalytic function of an Epsilon-class glutathione S-transferase of the silkworm

2013 ◽  
Vol 22 (5) ◽  
pp. 523-531 ◽  
Author(s):  
K. Yamamoto ◽  
Y. Aso ◽  
N. Yamada
1998 ◽  
Vol 66 (3) ◽  
pp. 1142-1148 ◽  
Author(s):  
Jean-Marie Grzych ◽  
Jan De Bont ◽  
Jinli Liu ◽  
Jean-Loup Neyrinck ◽  
Josette Fontaine ◽  
...  

ABSTRACT Sera from calves vaccinated with the recombinant Schistosoma bovis-derived 28-kDa glutathione S-transferase (28GST) and subsequently naturally or experimentally exposed toSchistosoma mattheei were studied for their content of specific immunoglobulin G (IgG) and IgA antibodies to recombinantS. bovis 28GST as well as for their capacity to inhibit the enzymatic activity of the antigen. The results were analyzed in regard to the presence (natural infection) or absence (experimental infection) of a protective effect(s) (reductions in worm burden, egg load, fecal egg counts, and excretion of viable eggs) toward S. mattheei challenge. Under such conditions, no differences in the IgG- and IgA-specific antibodies to recombinant S. bovis28GST or in the ability to block the catalytic function of the antigen between the two groups were recorded. Nevertheless, correlation analysis between the specific antibody responses to recombinantS. bovis 28GST and the inhibition of GST activity suggested an association with IgG in experimentally infected vaccinated animals, while in naturally infected vaccinated calves, the inhibitory activity appeared to be linked to a greater degree with IgA. These results suggest that in contrast to schistosomiasis in humans, IgG antibodies in calves with schistosomiasis may exhibit inhibitory functions toward GST enzymatic activity or have a modulatory effect on IgA antibody properties. Furthermore, sera from animals immunized with recombinantS. bovis 28GST recognized the native S. mattheei 28GST and achieved comparable levels of inhibition of activity of recombinant S. bovis 28GST and S. matthei 28GST, indicating the presence of cross-reactive epitopes on these two molecules.


2004 ◽  
Vol 383 (3) ◽  
pp. 483-490 ◽  
Author(s):  
Rungrutai UDOMSINPRASERT ◽  
Marie A. BOGOYEVITCH ◽  
Albert J. KETTERMAN

In mammalian systems, detoxification enzymes of the GST (glutathione S-transferase) family regulate JNK (c-Jun N-terminal kinase) signal transduction by interaction with JNK itself or other proteins upstream in the JNK pathway. In the present study, we have studied GSTs and their interaction with components of the JNK pathway from Diptera. We have evaluated the effects of four Delta class Anopheles dirus GSTs, GSTD1-1, GSTD2-2, GSTD3-3 and GSTD4-4, on the activity of full-length recombinant Drosophila HEP (mitogen-activated protein kinase kinase 7; where HEP stands for hemipterous) and the Drosophila JNK, as well as the reciprocal effect of these kinases on GST activity. Interestingly, even though these four GSTs are alternatively spliced products of the same gene and share >60% identity, they exerted different effects on JNK activity. GSTD1-1 inhibited JNK activity, whereas the other three GST isoforms activated JNK. GSTD2-2, GSTD3-3 and GSTD4-4 were inhibited 50–80% by HEP or JNK but GSTD1-1 was not inhibited by JNK. However, there were some similarities in the actions of HEP and JNK on these GSTs. For example, binding constants for HEP or JNK inhibiting a GST were similar (20–70 nM). Furthermore, after incubation of the GSTs with JNK, both JNK and the GSTs changed catalytic properties. The substrate specificities of both GSTs and JNK were also altered after their co-incubation. In addition, glutathione modulated the effects of JNK on GST activity. These results emphasize that different GST spliceforms possess different properties, both in their catalytic function and in their regulation of signalling through the JNK pathway.


1987 ◽  
Vol 248 (3) ◽  
pp. 937-941 ◽  
Author(s):  
P G Board ◽  
K Pierce

A plasmid, termed pTacGST2, which contains the complete coding sequence of a GST2 (glutathione S-transferase 2) subunit and permits the expression of the protein in Escherichia coli was constructed. The expressed protein had the same subunit Mr as the enzyme from normal human liver and retained its catalytic function with both GST and glutathione peroxidase activity. Antiserum raised against the bacterially synthesized protein cross-reacted with all the basic GST isoenzymes in human liver. The electrophoretic mobility in agarose of the bacterially expressed isoenzyme suggested that its pI is identical with that of the cationic isoenzyme from human liver previously termed GST2 type 1. The available evidence suggests that the three common cationic isoenzymes found in human liver are the products of two very similar gene loci.


VASA ◽  
2017 ◽  
Vol 46 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Alejandra María Zúñiga-Muñoz ◽  
Israel Pérez-Torres ◽  
Verónica Guarner-Lans ◽  
Elías Núñez-Garrido ◽  
Rodrigo Velázquez Espejel ◽  
...  

Abstract. Background: Aortic dilatation in Marfan syndrome (MFS) is progressive. It is associated with oxidative stress and endothelial dysfunction that contribute to the early acute dissection of the vessel and can result in rupture of the aorta and sudden death. We evaluated the participation of the glutathione (GSH) system, which could be involved in the mechanisms that promote the formation and progression of the aortic aneurysms in MFS patients. Patients and methods: Aortic aneurysm tissue was obtained during chest surgery from eight control subjects and 14 MFS patients. Spectrophotometrical determination of activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO) index, carbonylation, total antioxidant capacity (TAC), and concentration of reduced and oxidized glutathione (GSH and GSSG respectively), was performed in the homogenate from aortic aneurysm tissue. Results: LPO index, carbonylation, TGF-β1, and GR activity were increased in MFS patients (p < 0.04), while TAC, GSH/GSSG ratio, GPx, and GST activity were significantly decreased (p < 0.04). Conclusions: The depletion of GSH, in spite of the elevated activity of GR, not only diminished the activity of GSH-depend GST and GPx, but increased LPO, carbonylation and decreased TAC. These changes could promote the structural and functional alterations in the thoracic aorta of MFS patients.


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.


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