scholarly journals The oxidation of reduced glutathione and other sulphydryl compounds

1923 ◽  
Vol 94 (661) ◽  
pp. 266-297 ◽  
Keyword(s):  
Reduced Glutathione ◽  
Reduction Processes ◽  
Peptide Linkage ◽  
Glutaminic Acid ◽  
A Cell ◽  
Exact Position ◽  
Dynamic Oxidation ◽  
Sulphydryl Compounds ◽  
Cell Constituent

Hopkins (1) has recently isolated a cell constituent, glutathione, which would appear to play an important part in the dynamic oxidation and reduction processes in the tissues. The substance is a dipeptide of cystein and glutaminic acid, but the exact position of the peptide linkage has not yet been determined. For convenience the formula may be written G . SH, where G represents the residue of the cystein molecule linked with glutaminic acid. On oxidation the substance is converted to the disulphide form G . S . S . G in a manner strictly analogous to the conversion of cystein to cystine.

scholarly journals Immunomodulatory role of phagocyte-derived chloramines involving lymphocyte glutathione

1993 ◽  
Vol 2 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Véronique Witko-Sarsat ◽  
Anh Thu Nguyen ◽  
Béatrice Descamps-Latscha
Keyword(s):  
Oxidative Stress ◽  
Reduced Glutathione ◽  
Human Lymphocytes ◽  
Cell System ◽  
Polymorphonuclear Neutrophils ◽  
Myristate Acetate ◽  
Defensive Role ◽  
Free Model ◽  
A Cell

This study shows that human lymphocytes markedly decrease chloramines (long-lived oxidants) generated by polymorphonuclear neutrophils (PMN) after stimulation by phorbol-myristate-acetate or opsonized zymosan. In a cell-free model, reduced glutathione (GSH) scavenged chloramines, giving rise to oxidized glutathione (GSSG). In the cell system, treatment of lymphocytes with autologous PMN-derived chloramines induced a profound decrease in their total and reduced glutathione (GSH) content and markedly inhibited their proliferate responses to concanavalin-A and, to a lesser extent, phytohaemagglutinin. It is concluded that (i) lymphocytes may play a defensive role against phagocyte-derived oxidative stress by scavenging chloramines, and (ii) as this effect which is mediated by GSH affects lymphocyte proliferative responses, it may help to elucidate the still obscure mechanisms of oxidative stress associated immunodeficiency.

scholarly journals Alloxan-induced luminol luminescence as a tool for investigating mechanisms of radical-mediated diabetogenicity

1981 ◽  
Vol 200 (3) ◽  
pp. 685-690 ◽  
Author(s):  
K Grankvist
Keyword(s):  
Superoxide Dismutase ◽  
Hydroxyl Radicals ◽  
Metal Ion ◽  
Reduced Glutathione ◽  
Chemical Reactivity ◽  
Free System ◽  
A Cell ◽  
Radical Generation ◽  
Metal Ion Chelators

Chemiluminescence of luminol in a cell-free system was used to investigate the mechanism of alloxan-dependent free-radical generation. In the presence of alloxan and reduced glutathione (GSH), luminescence was greatly stimulated by FeSO4. Replacing GSH by oxidized glutathione or NAD(P)(H), or replacing FeSO4 by CuSO4, ZNSO4 or FeCl3, did not yield chemiluminescence. The chemiluminescence of a mixture of alloxan. GSH, FeSO4 and luminol was inhibited by catalase, superoxide dismutase, scavengers of hydroxyl radicals (sodium benzoate, n-butanol, D-mannitol, dimethyl sulphoxide) or metal-ion chelators (EDTA, diethylenetriaminepenta-acetic acid, diethyldithiocarbamate. desferroxamine), D-glucose, L-glucose, D-mannose, D-fructose, 3-O-methyl-D-glucose, NAD+, NADH, NADP+ or NADPH, but not by urea or enzymically inactive superoxide dismutase. The results support the hypothesis that the diabetogenic action of alloxan is mediated by hydroxyl radicals generated in an iron-catalysed reaction. Protection against alloxan in vivo depends both on the chemical reactivity of protector with radicals or radical-generating systems and on the stereospecific requirement of some strategic site in the B-cell.

scholarly journals Partial Characterization of Biosurfactant fromLactobacillus pentosusand Comparison with Sodium Dodecyl Sulphate for the Bioremediation of Hydrocarbon Contaminated Soil

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
A. B. Moldes ◽  
R. Paradelo ◽  
X. Vecino ◽  
J. M. Cruz ◽  
E. Gudiña ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Contaminated Soil ◽  
Sodium Dodecyl Sulphate ◽  
Day Treatment ◽  
Sodium Dodecyl ◽  
Carbonyl Groups ◽  
Lactobacillus Pentosus ◽  
Peptide Linkage ◽  
A Cell

The capability of a cell bound biosurfactant produced byLactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-). The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR) that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage), as well as CH2–CH3and C–O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000 mg Kg−1of octane was treated with biosurfactant fromL. pentosusor SDS. Treatment of soil for 15 days with the biosurfactant produced byL. pentosusled to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced byL. pentosusaccelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment.

scholarly journals Bacterial attack on phenolic ethers: An enzyme system demethylating vanillic acid

1967 ◽  
Vol 102 (3) ◽  
pp. 826-841 ◽  
Author(s):  
N. J. Cartwright ◽  
A. R. W. Smith
Keyword(s):  
Formate Dehydrogenase ◽  
Soluble Fraction ◽  
Enzyme System ◽  
Reduced Glutathione ◽  
Ring Cleavage ◽  
Formaldehyde Dehydrogenase ◽  
Free System ◽  
Methyl Group ◽  
Oxidative Demethylation ◽  
A Cell

1. A cell-free system from Pseudomonas fluorescens catalysed the oxidative demethylation and subsequent ring-cleavage of vanillate, with uptake of 2.5 moles of oxygen/mole of substrate. 2. Demethylation involved absorption of 0.5 mole of oxygen/mole, and required reduced glutathione (GSH) and nucleotide (probably NADPH) as cofactors, with further possible requirements, the natures of which are discussed. 3. Incomplete evidence suggested that the aromatic ring was opened via protocatechuate and the appropriate oxygenase, with absorption of 1 mole of oxygen/mole of substrate, eventually yielding beta-oxoadipate. 4. The methyl group was removed sequentially as formaldehyde, formate and carbon dioxide, the steps catalysed respectively by formaldehyde dehydrogenase, which required GSH and NAD(+), and formate dehydrogenase. Each enzyme was cytochrome-linked and accounted for absorption of 0.5mole of oxygen/mole of substrate. 5. All enzymes except formate dehydrogenase, which was a cell-wall enzyme, resided in the soluble fraction of the extract. The demethylase could not be resolved because of unknown cofactor requirements.

scholarly journals Characteristic of the micromorphological state of the soils of the flood-lands of the Samara river

2016 ◽  
Vol 17 (3-4) ◽  
pp. 81-89
Author(s):  
O. V. Stryzhak
Keyword(s):  
Pore Space ◽  
High Water ◽  
Forest Vegetation ◽  
Plant Residues ◽  
Porous Network ◽  
Reduction Processes ◽  
Large Size ◽  
Oxidation Reduction ◽  
Burrowing Activity ◽  
Dynamic Oxidation

The main micromorphological properties of the soils of the riverine valleys, the central and the terrain part of the Samara river have been revealed. The main factors that influence the creation of such a micromorphological organization of these soils are revealed. The basic micromorphological features of the soils of the pririal shaft are: plasma-sand microstructure, humus-argillaceous plasma, which is located in the form of films along grains of minerals; poorly developed porous network, represented mainly by pores-packings; weak aggregation of horizons. The fraction of grains of large size dominates in the skeleton. They are characterized by good roundness. The main reason for such a micromorphological organization of these soils is the immediate proximity to the Samara river. Due to the high water, some horizons can be washed off, or on the contrary, they can be washed by new ones due to the deposition of illuvial material. With the distance from the river and, accordingly, with the decrease in the influence of flood, the biological influence (forest vegetation and the activity of soil organisms) on the micromorphological properties of the soils of the central floodplain increases. This manifests itself in good structuring, developed pore network of upper horizons, presence of organic residues at different stages of decomposition. In the profile, microstructure is inhomogeneous, in the upper horizons it is dusty-plasma, with depth changing to sand-plasma and in the lower horizons – plasma-sandy. Skeletal grains are characterized by traces of transport on their surface (scratches) and good roundness. The plasma is humus-clay, with a share of clay plasma decreases. The clay part of the plasma is characterized by birefringence, orientation and the ability to rebuild. The pore space is most developed in the upper horizons due to burrowing activity of earthworms. With depth, the pore area decreases, often their walls are covered with clay kutans due to illuvial processes. The formation of the profile and the characteristic micromorphological organization of the soils of the central floodplain passed in several stages. The heavier fractions of the illuvial material were deposited on the underlying rocks with the weakening influence of floodplain processes. This can explain the great difference in the content and size of grains of minerals in the upper and lower horizons. Over time, the influence of forest vegetation and the burrowing activity of soil animals create entire coprolite horizons, which leads to an improvement in air and water conditions. The soils of the flood-lands of the Samara River are characterized by the presence of a large amount of plant residues in the upper horizons and a low content of grains of the skeleton. With the depth the plant residues gets less, and the grains of minerals gets more. The profile is characterized by the presence of a large variety of kutans. Specificity of micromorphological organization of soils of the terrain part of the flood-lands of the Samara River is due to the influence of forest vegetation, the close occurrence of groundwater and dynamic oxidation-reduction processes.

scholarly journals Metabolism of 4-chloro-2-methylphenoxyacetate by a soil pseudomonad. Ring-fission, lactonizing and delactonizing enzymes

1971 ◽  
Vol 122 (4) ◽  
pp. 533-542 ◽  
Author(s):  
J. K. Gaunt ◽  
W. C. Evans
Keyword(s):  
Metabolic Pathway ◽  
Reduced Glutathione ◽  
Single Step ◽  
Reaction Sequence ◽  
Free System ◽  
Cell Free System ◽  
Ring Fission ◽  
A Cell

1. A cell-free system, prepared from Pseudomonas N.C.I.B. 9340 grown on 4-chloro-2-methylphenoxyacetate (MCPA) was shown to catalyse the reaction sequence: 5-chloro-3-methylcatechol → cis–cis-γ-chloro-α-methylmuconate → γ-carboxymethylene-α-methyl-Δαβ-butenolide → γ-hydroxy-α-methylmuconate. 2. The activity of the three enzymes involved in these reactions was completely resolved and the lactonizing and delactonizing enzymes were separated. 3. This part of the metabolic pathway of 4-chloro-2-methylphenoxyacetate is thus confirmed for this bacterium. 4. The ring-fission oxygenase required Fe2+ or Fe3+ and reduced glutathione for activity; the lactonizing enzyme is stimulated by Mn2+, Mg2+, Co2+ and Fe2+; no cofactor requirement could be demonstrated for the delactonizing enzyme. 5. cis–cis-γ-Chloro-α-methylmuconic acid was isolated and found to be somewhat unstable, readily lactonizing to γ-carboxymethylene-α-methyl-Δαβ-butenolide. 6. Enzymically the lactonization appears to be a single-step dehydrochlorinase reaction.

scholarly journals Sperm-borne glutathione-S-transferase omega 2 accelerates the nuclear decondensation of spermatozoa during fertilization in mice†

2019 ◽  
Vol 101 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Lauren E Hamilton ◽  
Joao Suzuki ◽  
Luis Aguila ◽  
Marie-Charlotte Meinsohn ◽  
Olivia E Smith ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Reduced Glutathione ◽  
Specific Inhibitor ◽  
Sperm Nucleus ◽  
Glutathione S Transferase ◽  
Morula Stage ◽  
A Cell ◽  
Targeted Inhibition ◽  
Nuclear Decondensation

Abstract The postacrosomal sheath (PAS) of the perinuclear theca (PT) is the first compartment of the sperm head to solubilize into the ooplasm upon sperm-oocyte fusion, implicating its constituents in zygotic development. This study investigates the role of one such constituent, glutathione-S-transferase omega 2 (GSTO2), an oxidative-reductive enzyme found in the PAS and perforatorial regions of the PT. GSTO2 uses the conjugation of reduced glutathione, an electron donor shown to be compulsory in sperm disassembly within the ooplasm. The proximity of GSTO2 to the condensed sperm nucleus led us to hypothesize that this enzyme may facilitate nuclear decondensation by reducing disulfide bonds before the recruitment of GSTO enzymes from within the ooplasm. To test this hypothesis, we utilized a cell permeable isozyme-specific inhibitor, which fluoresces when bound to the active site of GSTO2, to functionally inhibit spermatozoa before performing intracytoplasmic sperm injections (ICSI) in mice. The technique allowed for targeted inhibition of solely PT-residing GSTO2, as all that is required for complete zygotic development is the injection of the mouse spermatozoon head. ICSI showed that inhibition of PT-anchored GSTO2 caused a delay in sperm nuclear decondensation, and further resulted in untimely embryo cleavage, and an increase in fragmentation beginning at the morula stage. The confounding effects of these developmental delays ultimately resulted in decreased blastocyst formation. This study implicates PT-anchored GSTO2 as an important facilitator of nuclear decondensation and reinforces the notion that the PAS-PT is a critical sperm compartment harboring molecules that facilitate zygotic development.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

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