scholarly journals The antioxidant action of human extracellular fluids. Effect of human serum and its protein components on the inactivation of α1-antiproteinase by hypochlorous acid and by hydrogen peroxide

1987 ◽  
Vol 243 (1) ◽  
pp. 219-223 ◽  
Author(s):  
M Wasil ◽  
B Halliwell ◽  
D C S Hutchison ◽  
H Baum
Keyword(s):  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Hydroxyl Radicals ◽  
Hypochlorous Acid ◽  
Antioxidant Action ◽  
Serum Samples ◽  
Inhibitory Capacity ◽  
Low Concentrations ◽  
High Concentrations ◽  
Protein Components

The elastase-inhibitory capacity of purified human alpha 1-antiproteinase is inactivated by low concentrations of the myeloperoxidase-derived oxidant hypochlorous acid, but much higher concentrations are required to inhibit the elastase-inhibitory capacity of serum samples. The protective effect of serum appears to be largely due to albumin. High concentrations of H2O2 also inactivate the elastase-inhibitory capacity of alpha 1-antiproteinase, by a mechanism not involving formation of hydroxyl radicals. Serum offers protection against H2O2 inactivation of alpha 1-antiproteinase. The relevance of these results to the tissue damage produced by activated phagocytes is discussed.

scholarly journals Effect of Pseudomonas moorei KB4 Cells’ Immobilisation on Their Degradation Potential and Tolerance towards Paracetamol

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 820
Author(s):  
Robert Surma ◽  
Danuta Wojcieszyńska ◽  
Jagna Karcz ◽  
Urszula Guzik
Keyword(s):  
Protective Effect ◽  
Kinetic Parameters ◽  
Toxicity Assessment ◽  
Bacterial Cells ◽  
Low Concentrations ◽  
Toxicity Analysis ◽  
Immobilised Cells ◽  
Degradation Activity ◽  
High Concentrations ◽  
The Hill

Pseudomonas moorei KB4 is capable of degrading paracetamol, but high concentrations of this drug may cause an accumulation of toxic metabolites. It is known that immobilisation can have a protective effect on bacterial cells; therefore, the toxicity and degradation rate of paracetamol by the immobilised strain KB4 were assessed. Strain KB4 was immobilised on a plant sponge. A toxicity assessment was performed by measuring the concentration of ATP using the colony-forming unit (CFU) method. The kinetic parameters of paracetamol degradation were estimated using the Hill equation. Toxicity analysis showed a protective effect of the carrier at low concentrations of paracetamol. Moreover, a pronounced phenomenon of hormesis was observed in the immobilised systems. The obtained kinetic parameters and the course of the kinetic curves clearly indicate a decrease in the degradation activity of cells after their immobilisation. There was a delay in degradation in the systems with free cells without glucose and immobilised cells with glucose. However, it was demonstrated that the immobilised systems can degrade at least ten succeeding cycles of 20 mg/L paracetamol degradation. The obtained results indicate that the immobilised strain may become a useful tool in the process of paracetamol degradation.

Biotin radioligand assay with an 125I-labeled biotin derivative, avidin, and avidin double-antibody reagents.

1987 ◽  
Vol 33 (11) ◽  
pp. 1983-1988 ◽  
Author(s):  
E Livaniou ◽  
G P Evangelatos ◽  
D S Ithakissios
Keyword(s):  
Pregnant Women ◽  
Binding Protein ◽  
Biological Fluids ◽  
Normal Subjects ◽  
Chronic Hemodialysis ◽  
Serum Samples ◽  
Radioligand Assay ◽  
Double Antibody ◽  
Low Concentrations ◽  
High Concentrations

Abstract We describe a new radioligand assay for determining biotin in biological fluids by using a mixture of N-[beta-(4-OH-3-125I-phenyl)ethyl]- and N-[beta-(4-OH-3,5-di-125I-phenyl)ethyl]biotinamides as radiotracer, avidin as a binding protein, and an avidin double-antibody as a separation reagent. The radiotracer is synthesized by coupling (at pH 8.5, 20-22 degrees C, 90 min) N-hydroxysuccinimidobiotin to radioiodinated tyramine. The assay curve is linear and the assay itself is sensitive (less than 10 ng/L), reproducible (intra- and interassay CVs 4.1% and 7.0%, respectively), and allows the simultaneous handling of more than 100 samples in less than 4 h. Serum samples from apparently normal subjects contained 100-840 ng of biotin per liter (mean 340 ng/L). Pregnant women had low concentrations of biotin (100-300 ng/L) in their serum. Patients undergoing chronic hemodialysis treatment showed high concentrations (0.5-3.0 micrograms/L), which may be ascribable to the inability of avidin, which was used as the assay binding protein, to distinguish biotin from biotinyl derivatives with an intact ureido ring.

Formation of Hydroxyl Radicals from Hydrogen Peroxide and Iron Salts by Superoxide- and Ascorbate-Dependent Mechanisms: Relevance to the Pathology of Rheumatoid Disease

1983 ◽  
Vol 64 (6) ◽  
pp. 649-653 ◽  
Author(s):  
D. A. Rowley ◽  
B. Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Oxygen Radicals ◽  
Rheumatoid Disease ◽  
Iron Salts ◽  
Low Concentrations ◽  
Short Period ◽  
Generating System

1. Superoxide and hydrogen peroxide are formed by activated phagocytes and react together in the presence of iron salts to form the hydroxyl radical, which attacks hyaluronic acid. Ascorbic acid also interacts with hydrogen peroxide and iron salts to form hydroxyl radical in a reaction independent of superoxide. Since iron salts, ascorbate and activated phagocytes are present in the rheumatoid joint, experiments were designed to see whether ascorbate-dependent or superoxide-dependent formation of hydroxyl radicals would be more important in vivo. 2. in the present study, addition of ascorbate to a superoxide-generating system at concentrations of 100 μmol/l provoked a superoxide-independent formation of hydroxyl radicals for a short period. Lower concentrations of ascorbate did not do this. It is therefore suggested that the superoxide-dependent reaction is probably more important. 3. It is further suggested that destruction of ascorbate by oxygen radicals formed by activated phagocytes accounts for the previously reported low concentrations of this compound in the serum and synovial fluid of rheumatoid patients.

scholarly journals Peroxidase activity of hemoglobin and heme destruction in the presence of hydrogen peroxide and CT-DNA

2020 ◽  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Peroxidase Activity ◽  
Hypochlorous Acid ◽  
Iron Ion ◽  
Acid Effect ◽  
High Concentrations ◽  
Ct Dna ◽  
Heme Destruction ◽  
Protein Environment

The aim of this study was to investigate the peroxidase activity of Hb with different concentrations of hydrogen peroxide and compare it with hypochlorous acid effect on Hb. Hypochlorous acid at higher concentrations decomposed Hb and heme, releasing fee iron ion from the metal center. High concentrations of hydrogen peroxide switched the peroxidase activity of Hb towards the partial Hb and heme destruction. Heme alone was degraded showing that the Hb conformation and protein environment protects Hb from the distraction in the presence of highly increased hydrogen peroxide concentration that occurs as a result of oxidative stress. In the presence of CT-DNA acted inhibition of the peroxidase activity of Hb was observed signaling inhibited hydrogen peroxide consumption.

scholarly journals The antioxidant action of taurine, hypotaurine and their metabolic precursors

1988 ◽  
Vol 256 (1) ◽  
pp. 251-255 ◽  
Author(s):  
O I Aruoma ◽  
B Halliwell ◽  
B M Hoey ◽  
J Butler
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Radical ◽  
Hypochlorous Acid ◽  
Cysteic Acid ◽  
Iron Ions ◽  
Antioxidant Action ◽  
Iron Ion ◽  
Metabolic Precursors ◽  
Sufficient Concentration

It has been suggested that taurine, hypotaurine and their metabolic precursors (cysteic acid, cysteamine and cysteinesulphinic acid) might act as antioxidants in vivo. The rates of their reactions with the biologically important oxidants hydroxyl radical (.OH), superoxide radical (O2.-), hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) were studied. Their ability to inhibit iron-ion-dependent formation of .OH from H2O2 by chelating iron ions was also tested. Taurine does not react rapidly with O2.-, H2O2 or .OH, and the product of its reaction with HOCl is still sufficiently oxidizing to inactivate alpha 1-antiproteinase. Thus it seems unlikely that taurine functions as an antioxidant in vivo. Cysteic acid is also poorly reactive to the above oxidizing species. By contrast, hypotaurine is an excellent scavenger of .OH and HOCl and can interfere with iron-ion-dependent formation of .OH, although no reaction with O2.- or H2O2 could be detected within the limits of our assay techniques. Cysteamine is an excellent scavenger of .OH and HOCl; it also reacts with H2O2, but no reaction with O2.- could be measured within the limits of our assay techniques. It is concluded that cysteamine and hypotaurine are far more likely to act as antioxidants in vivo than is taurine, provided that they are present in sufficient concentration at sites of oxidant generation.

Protection of ceruloplasmin by lactoferrin against hydroxyl radicals is pH dependent1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 397-404 ◽  
Author(s):  
Alexey V. Sokolov ◽  
Kirill V. Solovyov ◽  
Valeria A. Kostevich ◽  
Andrey V. Chekanov ◽  
Maria O. Pulina ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Hydroxyl Radicals ◽  
Review Process ◽  
Copper Ions ◽  
Peer Review Process ◽  
Copper Binding ◽  
Special Issue ◽  
Ph Dependent ◽  
Good Agreement

Destruction of ceruloplasmin (Cp) in the presence of hydrogen peroxide is accompanied by the release of the protein’s copper ions that provoke formation of hydroxyl radicals (OH˙) and, consequently, further degradation of the protein. Under such conditions, degradation of Cp is hampered by a number of substances able to bind copper ions. Lactoferrin (Lf) is the most active protector of Cp, its protective effect depending on the pH of the medium. The best protection of Cp by Lf was detected at pH 7.4. In an acidic buffer (pH 5.5), Lf did not affect the destruction of Cp. The pH-dependent efficiency of copper binding by Lf is in good agreement with its capacity to protect Cp against degradation provoked by hydrogen peroxide. It seems likely that peroxide-dependent degradation of Cp stimulated by its own copper ions is a part of neutrophil-induced antimicrobial reactions and may take place properly at the foci of inflammation. Interaction of Lf with Cp may regulate the generation of OH˙ from hydrogen peroxide in the foci of inflammation and protect the adjacent tissues.

scholarly journals Formation of hydroxyl radicals from hydrogen peroxide in the presence of iron. Is haemoglobin a biological Fenton reagent?

1988 ◽  
Vol 249 (1) ◽  
pp. 185-190 ◽  
Author(s):  
A Puppo ◽  
B Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Reactive Species ◽  
Iron Ions ◽  
Fenton Reagent ◽  
Low Concentrations ◽  
Free Haemoglobin ◽  
The Brain ◽  
Damaging Effects

The ability of oxyhaemoglobin and methaemoglobin to generate hydroxyl radicals (OH.) from H2O2 has been investigated using deoxyribose and phenylalanine as ‘detector molecules’ for OH.. An excess of H2O2 degrades methaemoglobin, releasing iron ions that react with H2O2 to form a species that appears to be OH.. Oxyhaemoglobin reacts with low concentrations of H2O2 to form a ‘reactive species’ that degrades deoxyribose but does not hydroxylate phenylalanine. This ‘reactive species’ is less amenable to scavenging by certain scavengers (salicylate, phenylalanine, arginine) than is OH., but it appears more reactive than OH. is to others (Hepes, urea). The ability of haemoglobin to generate not only this ‘reactive species’, but also OH. in the presence of H2O2 may account for the damaging effects of free haemoglobin in the brain, the eye, and at sites of inflammation.

An ESR study of irradiated mixtures of hydrogen peroxide and Cu(II) complexes at 77 K

1988 ◽  
Vol 53 (12) ◽  
pp. 3080-3088 ◽  
Author(s):  
Pavel Stopka
Keyword(s):  
Hydrogen Peroxide ◽  
High Pressure ◽  
Catalytic Activity ◽  
Oxalic Acid ◽  
Hydroxyl Radicals ◽  
Room Temperature ◽  
Active Species ◽  
Mercury Lamp ◽  
Catalytically Active ◽  
High Concentrations

When aqueous solutions containing hydrogen peroxide and CuSO4 are irradiated by a high-pressure mercury lamp at room temperature and at 77 K, hydrogen peroxide decomposes and hydroxyl radicals generated in high concentrations coordinate to CuSO4. The catalytic activity of Cu(II), which depends on the choice of the ligand (triene, diene, ethylenediamine, ammonia, EDTA, oxalic acid and glycerine) and the proportion between the monomeric and dimeric forms of the Cu(II) complex, shows a maximum at a concentration of 10-4 mol dm-3. The catalytically active species is the monomeric Cu(II) complex, the dimer being inactive.

scholarly journals Comparison of Proteome Composition of Serum Enriched in Extracellular Vesicles Isolated from Polycythemia Vera Patients and Healthy Controls

Proteomes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 20 ◽  
Author(s):  
Anna Fel ◽  
Aleksandra E. Lewandowska ◽  
Petro E. Petrides ◽  
Jacek R. Wiśniewski
Keyword(s):  
Polycythemia Vera ◽  
Extracellular Vesicles ◽  
Myeloproliferative Neoplasms ◽  
Healthy Controls ◽  
Serum Samples ◽  
Therapeutic Procedures ◽  
Q Exactive ◽  
Main Protein ◽  
High Concentrations ◽  
Protein Components

Extracellular vesicles (EVs), e.g., exosomes and microvesicles, are one of the main networks of intercellular communication. In myeloproliferative neoplasms, such as polycythemia vera (PV), excess of EVs originating from overabundant blood cells can directly contribute to thrombosis through their procoagulant activity. However, the proteomic composition of these vesicles in PV patients has not been investigated before. In this work, we examined the proteomic composition of serum EVs of PV patients in comparison to healthy controls. We processed EV-enriched serum samples using the Multiple Enzyme Filter Aided Sample Preparation approach (MED-FASP), conducted LC-MS/MS measurements on a Q-Exactive HF-X mass spectrometer, and quantitatively analyzed the absolute concentrations of identified proteins by the Total Protein Approach (TPA). Thirty-eight proteins were present at statistically significant different concentrations between PV patients’ study group and healthy controls’ group. The main protein components deregulated in PV were primarily related to excessive amounts of cells, increased platelet activation, elevated immune and inflammatory response, and high concentrations of procoagulant and angiogenic agents. Our study provides the first quantitative analysis of the serum EVs’ proteome in PV patients. This new knowledge may contribute to a better understanding of the secondary systemic effects of PV disease and further development of diagnostic or therapeutic procedures.

How to characterize an antioxidant: an update

1995 ◽  
Vol 61 ◽  
pp. 73-101 ◽  
Author(s):  
Barry Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Hydroxyl Radical ◽  
Hypochlorous Acid ◽  
Water Soluble ◽  
Peroxyl Radicals ◽  
Low Concentrations ◽  
Ferryl Species ◽  
Do So

The term antioxidant is widely used but rarely defined. One suggested definition is that an antioxidant is 'a substance that, when present at low concentrations compared with those of an oxidizable substrate, significantly delays or prevents oxidation of that substrate'. Many substances have been suggested to act as antioxidants in vivo, but few have been proved to do so. This chapter addresses the criteria necessary to evaluate a proposed antioxidant activity. Simple methods for assessing the possibility of physiologically feasible scavenging of important biological oxygen-derived species (superoxide, hydrogen peroxide, hydroxyl radical, hypochlorous acid, haem-associated ferryl species, radicals derived from activated phagocytes and peroxyl radicals, both lipid-soluble and water-soluble) are presented. Methods that may be used to gain evidence that a compound actually does function as an antioxidant in vivo are discussed.

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