scholarly journals Formation of hydroxyl radicals in the presence of ferritin and haemosiderin. Is haemosiderin formation a biological protective mechanism?

1986 ◽  
Vol 234 (3) ◽  
pp. 727-731 ◽  
Author(s):  
M O'Connell ◽  
B Halliwell ◽  
C P Moorhouse ◽  
O I Aruoma ◽  
H Baum ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Iron Overload ◽  
Hydroxyl Radicals ◽  
Oxygen Radical ◽  
Radical Reactions ◽  
Protective Mechanism ◽  
Reaction Conditions ◽  
Human Spleen

Horse spleen and human spleen ferritins increase the formation of hydroxyl radicals (OH) at both pH 4.5 and pH 7.4 in reaction mixtures containing ascorbic acid and H2O2. The generation of OH is inhibited by the chelator desferrioxamine. Human spleen haemosiderin also accelerates OH generation in identical reaction mixtures, but is far less effective (on a unit iron basis) than ferritin under all reaction conditions. It is proposed that conversion of ferritin into haemosiderin in iron overload is biologically advantageous in that it decreases the ability of iron to promote oxygen-radical reactions.

Low-molecular-weight iron complexes and oxygen radical reactions in idiopathic haemochromatosis

1985 ◽  
Vol 68 (4) ◽  
pp. 463-467 ◽  
Author(s):  
J. M. C. Gutteridge ◽  
D. A. Rowley ◽  
E. Griffiths ◽  
B. Halliwell
Keyword(s):  
Molecular Weight ◽  
Iron Overload ◽  
Membrane Lipids ◽  
Iron Complexes ◽  
Iron Chelator ◽  
Oxygen Radical ◽  
Radical Reactions ◽  
Low Molecular Weight ◽  
Iron Salts ◽  
Low Molecular Weight Iron

1. The sera of patients with idiopathic haemochromatosis and iron-overload have been found to contain low-molecular-weight iron complexes detectable in the ‘bleomycin assay'. 2. These complexes stimulate both the peroxidation of membrane lipids and the formation of the highly reactive and damaging hydroxyl radical. 3. The iron chelator desferrioxamine interferes with these reactions. 4. We suggest that oxygen radical reactions stimulated by iron salts are important in the pathology of idiopathic haemochromatosis.

scholarly journals Superoxide-dependent formation of hydroxyl radicals and lipid peroxidation in the presence of iron salts. Detection of ‘catalytic’ iron and anti-oxidant activity in extracellular fluids

1982 ◽  
Vol 206 (3) ◽  
pp. 605-609 ◽  
Author(s):  
John M. C. Gutteridge ◽  
David A. Rowley ◽  
Barry Halliwell
Keyword(s):  
Lipid Peroxidation ◽  
Molecular Weight ◽  
Hydroxyl Radicals ◽  
Oxygen Radical ◽  
Low Ph ◽  
Radical Reactions ◽  
Iron Catalysts ◽  
Ph Values ◽  
Iron Salts ◽  
Anti Oxidant

Synovial fluid from rheumatoid patients and normal cerebrospinal fluid contains micromolar concentrations of non-protein-bound iron salts that can promote lipid peroxidation and also the superoxide-dependent formation of hydroxyl radicals from hydrogen peroxide. These iron catalysts of oxygen radical reactions cannot be detected by conventional assays unless interfering high-molecular-weight substances, probably proteins, are removed by ultrafiltration or inactivated by exposure to low pH values. The bleomycin assay for ‘catalytic’ iron [Gutteridge, Rowley & Halliwell (1981) Biochem. J.199, 263–265] does not suffer from these artifacts.

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

Label-free proteomic analysis revealed the mechanisms of protein oxidation induced by hydroxyl radicals in whiteleg shrimp (Litopenaeus vannamei) muscle

2021 ◽  
Author(s):  
Hui-min Lin ◽  
Xue-er Qi ◽  
Shan-shan Shui ◽  
Soottawat Benjakul ◽  
Santiago P. Aubourg ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Hydroxyl Radicals ◽  
Litopenaeus Vannamei ◽  
Protein Oxidation ◽  
Proteomic Analysis ◽  
Muscle Proteins ◽  
Label Free ◽  
Whiteleg Shrimp ◽  
The Stability ◽  
Oxidative Effects

The oxidative effects of hydroxyl radicals derived from a FeCl3/ascorbic acid/H2O2 system on the stability of muscle proteins in peeled shrimp (Litopenaeus vannamei) were investigated.

Role of metals in oxygen radical reactions

1985 ◽  
Vol 1 (1) ◽  
pp. 3-25 ◽  
Author(s):  
Steven D. Aust ◽  
Lee A. Morehouse ◽  
Craig E. Thomas
Keyword(s):  
Oxygen Radical ◽  
Radical Reactions

scholarly journals Killing of Bacillus Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions

2003 ◽  
Vol 69 (4) ◽  
pp. 2245-2252 ◽  
Author(s):  
J. B. Cross ◽  
R. P. Currier ◽  
D. J. Torraco ◽  
L. A. Vanderberg ◽  
G. L. Wagner ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Dissolved Oxygen ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Copper Ions ◽  
Transition Metal Ions ◽  
Fenton Reagent ◽  
Bacillus Spores ◽  
Modified Fenton

ABSTRACT An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction involves the conversion of aqueous dissolved oxygen to hydrogen peroxide by an ionic catalyst (Cu2+) and then subsequent conversion to hydroxyl radicals. Results are given for the modified Fenton reagent deactivating spores of Bacillus globigii. A biocidal mechanism is proposed that is consistent with our experimental results and independently derived information found in the literature. This mechanism requires diffusion of relatively benign species into the interior of the spore, where dissolved O2 is then converted through a series of reactions which ultimately produce hydroxyl radicals that perform the killing action.

scholarly journals Effects of Iron Overload on Ascorbic Acid Metabolism

BMJ ◽  
1968 ◽  
Vol 3 (5620) ◽  
pp. 704-707 ◽  
Author(s):  
A. A. Wapnick ◽  
S. R. Lynch ◽  
P. Krawitz ◽  
H. C. Seftel ◽  
R. W. Charlton ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Iron Overload ◽  
Acid Metabolism

scholarly journals Nontransferrin-bound iron in plasma from hemochromatosis patients: effect of phlebotomy therapy

Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1416-1419 ◽  
Author(s):  
OI Aruoma ◽  
A Bomford ◽  
RJ Polson ◽  
B Halliwell
Keyword(s):  
Iron Overload ◽  
Binding Capacity ◽  
Radical Reactions ◽  
Iron Binding ◽  
Total Plasma ◽  
Free Radical Reactions ◽  
Low Concentrations ◽  
Idiopathic Hemochromatosis ◽  
Highly Correlated ◽  
Iron Binding Capacity

Abstract Plasma from patients with iron overload resulting from idiopathic hemochromatosis contains nontransferrin-bound iron, measurable by the bleomycin, assay. During venesection therapy, the concentration of bleomycin iron declines in a way highly correlated with plasma ferritin concentrations. Even when patients had been venesected to give very low total plasma iron concentrations and high transferrin iron-binding capacity, bleomycin-detectable iron was still present at low concentrations. Bleomycin-detectable iron can stimulate damaging free radical reactions, and its persistence in plasma even after prolonged venesection might contribute to the tissue damage that results from iron overload.

Effect of nano-sized iron overload with ascorbic acid on the formation of colonic pre-neoplastic lesions in mice

2016 ◽  
Vol 40 (3) ◽  
pp. 83-89 ◽  
Author(s):  
Jong-Hwi Park ◽  
◽  
Sung-June Kim ◽  
Jae-Hwang Jeong ◽  
Sang Yoon Nam ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Iron Overload ◽  
Neoplastic Lesions

scholarly journals Research communication copper-1,10-phenanthroline induces internucleosomal DNA fragmentation in HepG2 cells, resulting from direct oxidation by the hydroxyl radical

1996 ◽  
Vol 317 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Shui Ying TSANG ◽  
Shuk Ching TAM ◽  
Ian BREMNER ◽  
Mark J. BURKITT
Keyword(s):  
Ascorbic Acid ◽  
Low Temperature ◽  
Hydroxyl Radical ◽  
Dna Fragmentation ◽  
Hydroxyl Radicals ◽  
Hepg2 Cells ◽  
Redox Cycling ◽  
Endonuclease Activity ◽  
Direct Oxidation ◽  
Direct Attack

In view of the current speculation regarding the possible role of reactive oxygen species (ROS) in apoptosis, both under physiological conditions and in response to chemicals that promote their intracellular formation, the present investigation was undertaken to examine whether DNA fragmentation during oxidative stress results from endonuclease activity (apoptosis) or from direct attack by ROS. We report that the incubation of HepG2 cells (a human-derived hepatoma cell line) with the copper(II) complex of 1,10-phenanthroline, CuII(OP)2, results in internucleosomal DNA fragmentation, which is widely recognized as being a hallmark of apoptosis. DNA fragmentation did not occur at low temperature, but activity was restored by the addition of ascorbic acid. It is proposed that DNA fragmentation results from the direct attack of hydroxyl radicals upon DNA. Hydroxyl radicals are produced from oxygen by the redox-cycling of CuII(OP)2, which is supported by metabolic processes at normal temperature. At low temperature ascorbic acid provides an artificial cellular reducing environment, thereby restoring hydroxyl radical formation. These findings were confirmed by the detection of internucleosomal DNA fragmentation following the exposure of isolated chromatin to a biomimetic CuII(OP)2 redox-cycling system. We conclude that DNA laddering, the widely employed hallmark of apoptosis, is not unique to endonuclease activity and may also result from direct attack upon DNA by the hydroxyl radical.

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