scholarly journals Interrelationship between cationic and anionic forms of glutathione S-transferases of bovine ocular lens

1980 ◽  
Vol 191 (1) ◽  
pp. 11-20 ◽  
Author(s):  
R P Saneto ◽  
Y C Awasthi ◽  
S K Srivastava
Keyword(s):  
Amino Acid ◽  
Glutathione Peroxidase ◽  
Vascular System ◽  
Liver Homogenate ◽  
Physiological Role ◽  
Antigenic Determinants ◽  
Ocular Lens ◽  
Glutathione S Transferase ◽  
Amino Acid Compositions ◽  
Bovine Lens

Since the eye is constantly exposed to potentially damaging chemical compounds present in the atmosphere and vascular system, we investigated the physiological role of glutathione S-transferase (GSH S-transferase) in detoxification mechanisms operative in the ocular lens. We have purified an anionic and a cationic GSH S-transferase from the bovine lens to homogeneity through a combination of gel filtration, ion-exchange and affinity chromatography. The anionic (pI 5.6) and cationic (pI 7.4) S-transferases were found to have distinct kinetic parameters (apparent Km and Vmax. pH optimum and energy of activation). However, both species were demonstrated to have similar molecular weights and amino acid compositions. Double-immunodiffusion and immunotitration studies showed that both lens S-transferases were immunologically similar. The very close similarity in amino acid compositions and immunological properties strongly indicates that these two transferases either originate from the same gene or at least share common antigenic determinants and originate from similar genes. The bovine lens GSH S-transferases had no glutathione peroxidase activity with either t-butyl hydroperoxide or cumene hydroperoxide as substrate. However, the antibody raised against the homogeneous anionic glutathione S-transferase from the bovine lens was found to precipitate both glutathione S-transferase and glutathione peroxidase activities out of solution in the supernatant of a crude bovine liver homogenate.

Comparison of hemolysins of Vibrio cholerae non-O1 and Vibrio hollisae with thermostable direct hemolysin of Vibrio parahaemolyticus

1988 ◽  
Vol 34 (12) ◽  
pp. 1321-1324 ◽  
Author(s):  
Myonsun Yoh ◽  
Takeshi Honda ◽  
Toshio Miwatani
Keyword(s):  
Amino Acid ◽  
Vibrio Cholerae ◽  
Vibrio Parahaemolyticus ◽  
Antigenic Determinants ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Time Dependencies ◽  
Thermostable Direct Hemolysin ◽  
Effects Of Temperature ◽  
Vibrio Hollisae

Hemolysin (Vh-rTDH) produced by Vibrio hollisae and hemolysin (NAG-rTDH) produced by Vibrio cholerae non-O1 were characterized and compared with hemolysin (Vp-TDH) produced by Vibrio parahaemolyticus. These three hemolysins are each composed of two subunits and have similar, but not identical, molecular weights. The amino acid compositions of Vp-TDH and NAG-rTDH are similar, but are different from that of Vh-rTDH. The three hemolysins showed similar lethal toxicities to mice. The effects of temperature on hemolysis and the time dependencies of hemolysis by the three hemolysins were similar. The three were concluded to be immunologically related, but not identical, and to have common and also unique antigenic determinants.

Microsomal glutathione S-transferase A1-1 with glutathione peroxidase activity from sheep liver: molecular cloning, expression and characterization

2001 ◽  
Vol 360 (2) ◽  
pp. 345-354 ◽  
Author(s):  
K. Sandeep PRABHU ◽  
Padala V. REDDY ◽  
Eric GUMPRICHT ◽  
George R. HILDENBRANDT ◽  
Richard W. SCHOLZ ◽  
...  
Keyword(s):  
Amino Acid ◽  
Glutathione Peroxidase ◽  
Molecular Mass ◽  
Peroxidase Activity ◽  
Sequence Similarity ◽  
Liver Microsomes ◽  
Amino Acid Residues ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Sheep Liver

A 25kDa subunit of glutathione S-transferase (GST) from sheep liver microsomes (microsomal GSTA1-1) with a significant selenium-independent glutathione peroxidase activity has been isolated and characterized. Several analytical criteria, including EDTA stripping, protease protection assay and extraction with alkaline Na2CO3, indicate that the microsomal GSTA1-1 is associated with the inner microsomal membrane. The specific cDNA nucleotide sequence reveals that the enzyme is made up of 222 amino acid residues and shares approx. 73–83% sequence similarity to Alpha-class GSTs from different species. The molecular mass, as determined by electrospray mass ionization, is 25611.3Da. The enzyme is distinct from the previously reported rat liver microsomal GST in both amino acid sequence and catalytic properties [Morgenstern, Guthenberg and DePierre (1982) Eur. J. Biochem. 128, 243–248]. The microsomal GSTA1-1 differs from the sheep liver cytosolic GSTs, reported previously from this laboratory, in its substrate specificity profile and molecular mass [Reddy, Burgess, Gong, Massaro and Tu (1983) Arch. Biochem. Biophys. 224, 87–101]. In addition to catalysing the conjugation of 4-hydroxynonenal with GSH, the enzyme also exhibits significant glutathione peroxidase activity towards physiologically relevant fatty acid hydroperoxides, such as linoleic and arachidonic acid hydroperoxides, as well as phosphatidylcholine hydroperoxide, but not with H2O2. Thus the microsomal GSTA1-1 isoenzyme might have an important role in the protection of biological membranes against oxidative damage.

scholarly journals Purification and properties of anionic glutathione S-transferase from bovine ciliary body

1986 ◽  
Vol 237 (2) ◽  
pp. 365-371 ◽  
Author(s):  
H Shichi ◽  
P D O'Meara
Keyword(s):  
Amino Acid ◽  
Glutathione Peroxidase ◽  
Ciliary Body ◽  
Competitive Inhibitor ◽  
Transferase Activity ◽  
Glutathione Peroxidase Activity ◽  
Glutathione S Transferase ◽  
Substrate Specificities ◽  
Purification And Properties ◽  
Peptide Maps

An anionic glutathione S-transferase was purified from bovine ciliary body by DEAE-agarose chromatography and affinity chromatography on GSH-agarose and Orange A. The enzyme accounts for about 25% of total soluble glutathione S-transferase activity of the tissue. The purified enzyme has a molecular mass of about 50,000 Da and is composed of two identical subunits of about 25,000 Da. The enzyme has a pI of 5.8. The enzyme conjugates GSH with 1-chloro-2,4-dinitrobenzene, p-nitrobenzyl chloride, 1,2-epoxy-3-(p-nitrophenyl)propane, 1,2-dinitrobenzene and 3,4-dinitrobenzoic acid. The Km values for 1-chloro-2,4-dinitrobenzene and GSH are 0.40 mM and 0.57 mM respectively. Haematin is a non-competitive inhibitor (Ki = 4.5 microM) when tested with various concentrations of 1-chloro-2,4-dinitrobenzene. The enzyme shows no glutathione peroxidase activity with either H2O2 or cumene peroxide as substrate. On the basis of substrate specificities, pI values, amino acid composition and peptide maps, it is concluded that the ciliary-body enzyme is probably identical with the anionic form of glutathione S-transferase from bovine lens and liver.

Amino Acid Compositions of Common Edible Mushrooms

1995 ◽  
Vol 6 (3) ◽  
pp. 34-37
Author(s):  
Shinobu Fujihara ◽  
Atsuko Kasuga ◽  
Tatsuyuki Sugahara ◽  
Yasuo Aoyagi
Keyword(s):  
Amino Acid ◽  
Edible Mushrooms ◽  
Amino Acid Compositions

scholarly journals Effect of Cross-Sex Hormonal Replacement on Antioxidant Enzymes in Rat Retroperitoneal Fat Adipocytes

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Israel Pérez-Torres ◽  
Verónica Guarner-Lans ◽  
Alejandra Zúñiga-Muñoz ◽  
Rodrigo Velázquez Espejel ◽  
Alfredo Cabrera-Orefice ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Glutathione Peroxidase ◽  
Glutathione Reductase ◽  
Enzymatic Activities ◽  
Glutathione S Transferase ◽  
Control Groups ◽  
Intact Female ◽  
Hormonal Replacement

We report the effect of cross-sex hormonal replacement on antioxidant enzymes from rat retroperitoneal fat adipocytes. Eight rats of each gender were assigned to each of the following groups: control groups were intact female or male (F and M, resp.). Experimental groups were ovariectomized F (OvxF), castrated M (CasM), OvxF plus testosterone (OvxF + T), and CasM plus estradiol (CasM + E2) groups. After sacrifice, retroperitoneal fat was dissected and processed for histology. Adipocytes were isolated and the following enzymatic activities were determined: Cu-Zn superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR). Also, glutathione (GSH) and lipid peroxidation (LPO) were measured. In OvxF, retroperitoneal fat increased and adipocytes were enlarged, while in CasM rats a decrease in retroperitoneal fat and small adipocytes are observed. The cross-sex hormonal replacement in F rats was associated with larger adipocytes and a further decreased activity of Cu-Zn SOD, CAT, GPx, GST, GR, and GSH, in addition to an increase in LPO. CasM + E2exhibited the opposite effects showing further activation antioxidant enzymes and decreases in LPO. In conclusion, E2deficiency favors an increase in retroperitoneal fat and large adipocytes. Cross-sex hormonal replacement in F rats aggravates the condition by inhibiting antioxidant enzymes.

Reductant substrate for glutathione peroxidase modulates oxidant inhibition of Ca2+ signaling in endothelial cells

1995 ◽  
Vol 268 (1) ◽  
pp. H278-H287 ◽  
Author(s):  
S. J. Elliott ◽  
T. N. Doan ◽  
P. N. Henschke
Keyword(s):  
Endothelial Cells ◽  
Glutathione Peroxidase ◽  
Oxidant Stress ◽  
Glutathione S Transferase ◽  
Glutathione Redox Cycle ◽  
Tert Butyl Hydroperoxide ◽  
Intracellular Glutathione ◽  
Glutamylcysteine Synthetase ◽  
Dependent Signal

Oxidant stress mediated by tert-butyl hydroperoxide (t-BOOH) inhibits agonist-stimulated Ca2+ entry and internal store Ca2+ release in cultured endothelial cells. The role of intracellular glutathione in modulating the effects of oxidant stress on Ca2+ signaling was determined in cells preincubated with buthionine-[S,R]-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or 1-chloro-2,4-dinitrobenzene (CDNB), a cosubstrate for glutathione-S-transferase. BSO and CDNB decreased endothelial cell glutathione content by 85 and 97%, respectively (control glutathione, 21.5 +/- 2.3 nmol/mg protein). Each agent accelerated the time-dependent effects of t-BOOH on Ca2+ signaling in fura 2-loaded cells and potentiated the inhibition of bradykinin-stimulated 45Ca2+ efflux induced by t-BOOH. These results indicate that decreased availability of reduced glutathione, the primary cosubstrate for glutathione peroxidase, potentiates the effect of hydroperoxide oxidant stress on receptor-operated Ca2+ entry across the plasmalemma and Ca2+ release from internal stores. The present findings suggest that intracellular glutathione availability and/or glutathione redox cycle activity are critically important modulators of oxidant inhibition of Ca(2+)-dependent signal transduction.

scholarly journals The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins

2001 ◽  
Vol 355 (3) ◽  
pp. 663-670 ◽  
Author(s):  
Claudia TROST ◽  
Christiane BERGS ◽  
Nina HIMMERKUS ◽  
Veit FLOCKERZI
Keyword(s):  
Amino Acid ◽  
Ion Channels ◽  
Transient Receptor Potential ◽  
Direct Interaction ◽  
Receptor Potential ◽  
Amino Acid Residues ◽  
Glutathione S Transferase ◽  
Calmodulin Binding ◽  
Transient Receptor

The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca2+-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca2+-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1) retention of in vitro translated TRP4 and of TRP4 protein solubilized from bovine adrenal cortex by CaM–Sepharose in the presence of Ca2+, and (2) TRP4–glutathione S-transferase pull-down experiments. Two domains of TRP4, amino acid residues 688–759 and 786–848, were identified as being able to interact with CaM. The binding of CaM to both domains occurred only in the presence of Ca2+ concentrations above 10µM, with half maximal binding occurring at 16.6µM (domain 1) and 27.9µM Ca2+ (domain 2). Synthetic peptides, encompassing the two putative CaM binding sites within these domains and covering amino acid residues 694–728 and 829–853, interacted directly with dansyl–CaM with apparent Kd values of 94–189nM. These results indicate that TRP4/Ca2+-CaM are parts of a signalling complex involved in agonist-induced Ca2+ entry.

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