Tryptophan residues are targets in hypothiocyanous acid-mediated protein oxidation

2008 ◽  
Vol 416 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Clare L. Hawkins ◽  
David I. Pattison ◽  
Naomi R. Stanley ◽  
Michael J. Davies
Keyword(s):  
Protein Oxidation ◽  
Hypochlorous Acid ◽  
Inflammatory Diseases ◽  
Thiol Group ◽  
Oxidation Products ◽  
Cellular Damage ◽  
Halide Ions ◽  
Peptide Mass ◽  
Tryptophan Residues ◽  
Oxygen Atoms

Myeloperoxidase, released by activated phagocytes, forms reactive oxidants by catalysing the reaction of halide and pseudo-halide ions with H2O2. These oxidants have been linked to tissue damage in a range of inflammatory diseases. With physiological levels of halide and pseudo-halide ions, similar amounts of HOCl (hypochlorous acid) and HOSCN (hypothiocyanous acid) are produced by myeloperoxidase. Although the importance of HOSCN in initiating cellular damage via thiol oxidation is becoming increasingly recognized, there are limited data on the reactions of HOSCN with other targets. In the present study, the products of the reaction of HOSCN with proteins has been studied. With albumin, thiols are oxidized preferentially forming unstable sulfenyl thiocyanate derivatives, as evidenced by the reversible incorporation of 14C from HOS14CN. On consumption of the HSA (human serum albumin) free thiol group, the formation of stable 14C-containing products and oxidation of tryptophan residues are observed. Oxidation of tryptophan residues is observed on reaction of HOSCN with other proteins (including myoglobin, lysozyme and trypsin inhibitor), but not free tryptophan, or tryptophan-containing peptides. Peptide mass mapping studies with HOSCN-treated myoglobin, showed the addition of two oxygen atoms on either Trp7 or Trp14 with equimolar or less oxidant, and the addition of a further two oxygen atoms to the other tryptophan with higher oxidant concentrations (≥2-fold). Tryptophan oxidation was observed on treating myoglobin with HOSCN in the presence of glutathione and ascorbate. Thus tryptophan residues are likely to be favourable targets for the reaction in biological systems, and the oxidation products formed may be useful biomarkers of HOSCN-mediated protein oxidation.

scholarly journals Myeloperoxidase Modulates Hydrogen Peroxide Mediated Cellular Damage in Murine Macrophages

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1255
Author(s):  
Chaorui Guo ◽  
Inga Sileikaite ◽  
Michael J. Davies ◽  
Clare L. Hawkins
Keyword(s):  
Hydrogen Peroxide ◽  
Hypochlorous Acid ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Innate Immune ◽  
Cellular Damage ◽  
Enzymatic System ◽  
Therapeutic Approaches ◽  
Macrophage Cell

Myeloperoxidase (MPO) is involved in the development of many chronic inflammatory diseases, in addition to its key role in innate immune defenses. This is attributed to the excessive production of hypochlorous acid (HOCl) by MPO at inflammatory sites, which causes tissue damage. This has sparked wide interest in the development of therapeutic approaches to prevent HOCl-induced cellular damage including supplementation with thiocyanate (SCN−) as an alternative substrate for MPO. In this study, we used an enzymatic system composed of glucose oxidase (GO), glucose, and MPO in the absence and presence of SCN−, to investigate the effects of generating a continuous flux of oxidants on macrophage cell function. Our studies show the generation of hydrogen peroxide (H2O2) by glucose and GO results in a dose- and time-dependent decrease in metabolic activity and cell viability, and the activation of stress-related signaling pathways. Interestingly, these damaging effects were attenuated by the addition of MPO to form HOCl. Supplementation with SCN−, which favors the formation of hypothiocyanous acid, could reverse this effect. Addition of MPO also resulted in upregulation of the antioxidant gene, NAD(P)H:quinone acceptor oxidoreductase 1. This study provides new insights into the role of MPO in the modulation of macrophage function, which may be relevant to inflammatory pathologies.

Serum levels of protein oxidation products in patients with nickel allergy

2009 ◽  
Vol 30 (5) ◽  
pp. 552-557 ◽  
Author(s):  
Sebastiano Gangemi ◽  
Luisa Ricciardi ◽  
Paola Lucia Minciullo ◽  
Mariateresa Cristani ◽  
Salvatore Saitta ◽  
...  
Keyword(s):  
Protein Oxidation ◽  
Serum Levels ◽  
Oxidation Products ◽  
Nickel Allergy

scholarly journals Endogenous formaldehyde scavenges cellular glutathione resulting in cytotoxic redox disruption

2020 ◽  
Author(s):  
Carla Umansky ◽  
Agustín Morellato ◽  
Marco Scheidegger ◽  
Matthias Rieckher ◽  
Manuela R. Martinefski ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Fanconi Anemia ◽  
Redox Homeostasis ◽  
Thiol Group ◽  
Cellular Damage ◽  
Repair Pathway ◽  
Cellular Redox ◽  
Redox Active ◽  
Development And Aging

AbstractFormaldehyde (FA) is a ubiquitous endogenous and environmental metabolite that is thought to exert cytotoxicity through DNA and DNA-protein crosslinking. We show here that FA can cause cellular damage beyond genotoxicity by triggering oxidative stress, which is prevented by the enzyme alcohol dehydrogenase 5 (ADH5/GSNOR). Mechanistically, we determine that endogenous FA reacts with the redox-active thiol group of glutathione (GSH) forming S-hydroxymethyl-GSH, which is metabolized by ADH5 yielding reduced GSH thus preventing redox disruption. We identify the ADH5-ortholog gene in Caenorhabditis elegans and show that oxidative stress also underlies FA toxicity in nematodes. Moreover, we show that endogenous GSH can protect cells lacking the Fanconi Anemia DNA repair pathway from FA, which might have broad implications for Fanconi Anemia patients and for healthy BRCA2-mutation carriers. We thus establish a highly conserved mechanism through which endogenous FA disrupts the GSH-regulated cellular redox homeostasis that is critical during development and aging.

scholarly journals Cellular effects of gliotoxin: Evaluation of a proteomic, isotope-based method to detect reactive cysteines

2021 ◽  
Author(s):  
◽  
Sven Sondhauss
Keyword(s):  
Large Scale ◽  
Thiol Group ◽  
Disulfide Bridge ◽  
Reversed Phase ◽  
Cellular Damage ◽  
Full Potential ◽  
Label Free ◽  
Cysteine Modification ◽  
Affinity Tag ◽  
Cell Vitality

<p>Cysteinyl residues in proteins are important for many cellular processes and unregulated modification of the cysteine thiol group can have negative effects on cell vitality and viability. In this thesis, the potential for use of the isotope coded affinity tag (ICAT) method for detection of cysteine modification has been investigated. ICAT reagents label free cysteine thiols. The aim of this study was to use HL-60 cells treated with gliotoxin, a fungal metabolite with a reactive disulfide bridge, as a system to evaluate the performance of ICAT for identification of cysteine modification in a whole cell proteome. Gliotoxin has antimicrobial, antitumor, immunosuppressive and cytotoxic properties that have been related to cysteine modification in proteins. Cellular assays including viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell cycle analysis, and measurement of reactive oxygen species using dichlorofluorescin diacetate were used to establish conditions for measuring the effects of gliotoxin on HL-60 cells prior to large-scale cellular damage. Cells exposed to gliotoxin and control cells were then labeled with ICAT reagents and analysed by offline reversed phase liquid chromatography followed by matrix-assisted laser desorption/ionization tandem mass spectrometry. The pilot results identified tubulin, glyceraldehyde-3-phosphate dehydrogenase and peptidyl-prolyl cis-trans isomerase as putative targets of gliotoxin. Additionally, this study showed that ICAT can be used to detect modified cysteines from a highly complex sample, but further optimization is needed to unlock the full potential for detection of cysteine modification in complex samples.</p>

Abstract 132: A Novel Hydrogen Sulfide (H 2 S) Prodrug, SG1002, Protects Against Myocardial Oxidative Damage and Hypertrophic Signaling via Induction of Cystathionine Β-Synthase (CBS) and Antioxidant Proteins

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Kazi N Islam ◽  
Erminia Donnarumma ◽  
Erinn Donnelly ◽  
David J Lefer
Keyword(s):  
Oxidative Stress ◽  
Clinical Utility ◽  
Culture Media ◽  
Therapeutic Strategies ◽  
Oxidation Products ◽  
Cellular Damage ◽  
Serum Starvation ◽  
Antioxidant Proteins ◽  
Hypertrophic Signaling ◽  
Cells Cultured

Background: Endogenously produced H 2 S is critical for cardiovascular homeostasis. Therapeutic strategies aimed at increasing H 2 S levels have proven cardioprotective in models of acute myocardial infarction and heart failure (HF). The present study was under taken to investigate the effects of a novel H 2 S prodrug, SG1002, on stress induced hypertrophic signaling in murine HL1 cardiomyocytes. Methods: HL1 cells were maintained either in serum starvation (1%) or serum containing (10%) media followed by treatment either with SG1002 or H 2 O 2 , or endothelin-1 (ET-1)/phenylephrine (Phe) or in combination. Treated cells were analyzed for specific experimental needs. Results: SG1002 significantly increased cellular levels of the H 2 S producing enzyme, CBS, as well as production of H 2 S and nitrosothiol in HL1 cells cultured both in serum starvation or serum containing media. SG1002 significantly inhibited H 2 O 2 and ET-1/Phe induced oxidative stress in both culture media as measured by advanced protein oxidation products and MDA levels. Expression of ANP and BNP were markedly attenuated by SG1002 treatment. Cells cultured in media supplemented with serum containing H 2 O 2 /(ET-1 or Phe) or in 1% serum exhibited decreased levels of CBS, SOD1, and catalase. When the HL1 cells were coincubated with SG1002 cellular damage from oxidative stress was significantly attenuated accompanied by an increase in CBS expression. Conclusion: Our data clearly demonstrate that SG1002 attenuates myocardial cellular damage via increasing antioxidant proteins. SG1002 directly increases H 2 S levels and upregulates CBS. Studies are currently underway to evaluate the clinical utility of SG1002 in HF.

Chemical Stability of Proteins in Foods: Oxidation and the Maillard Reaction

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mahesha M. Poojary ◽  
Marianne N. Lund
Keyword(s):  
Maillard Reaction ◽  
Protein Oxidation ◽  
Oxidation Products ◽  
Protein Carbonyls ◽  
Annual Review ◽  
Publication Date ◽  
Food Protein ◽  
Food Proteins ◽  
Wide Range ◽  
Specific Oxidation

Protein is a major nutrient present in foods along with carbohydrates and lipids. Food proteins undergo a wide range of modifications during food production, processing, and storage. In this review, we discuss two major reactions, oxidation and the Maillard reaction, involved in chemical modifications of food proteins. Protein oxidation in foods is initiated by metal-, enzyme-, or light-induced processes. Food protein oxidation results in the loss of thiol groups and the formation of protein carbonyls and specific oxidation products of cysteine, tyrosine, tryptophan, phenylalanine, and methionine residues, such as disulfides, dityrosine, kynurenine, m-tyrosine, and methionine sulfoxide. The Maillard reaction involves the reaction of nucleophilic amino acid residues with reducing sugars, which yields numerous heterogeneous compounds such as α-dicarbonyls, furans, Strecker aldehydes, advanced glycation end-products, and melanoidins. Both protein oxidation and the Maillard reaction result in the loss of essential amino acids but may positively or negatively impact food structure and flavor. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals The Emerging Relevance of AIM2 in Liver Disease

2020 ◽  
Vol 21 (18) ◽  
pp. 6535
Author(s):  
Beatriz Lozano-Ruiz ◽  
José M. González-Navajas
Keyword(s):  
Liver Disease ◽  
Inflammatory Diseases ◽  
Research Area ◽  
Cellular Damage ◽  
Inflammasome Activation ◽  
Immune Recognition ◽  
Alcoholic Fatty Liver ◽  
Hepatic Diseases ◽  
Life Threatening ◽  
New Research

Absent in melanoma 2 (AIM2) is a cytosolic receptor that recognizes double-stranded DNA (dsDNA) and triggers the activation of the inflammasome cascade. Activation of the inflammasome results in the maturation of inflammatory cytokines, such as interleukin (IL)-1 β and IL-18, and a form of cell death known as pyroptosis. Owing to the conserved nature of its ligand, AIM2 is important during immune recognition of multiple pathogens. Additionally, AIM2 is also capable of recognizing host DNA during cellular damage or stress, thereby contributing to sterile inflammatory diseases. Inflammation, either in response to pathogens or due to sterile cellular damage, is at the center of the most prevalent and life-threatening liver diseases. Therefore, during the last 15 years, the study of inflammasome activation in the liver has emerged as a new research area in hepatology. Here, we discuss the known functions of AIM2 in the pathogenesis of different hepatic diseases, including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), hepatitis B, liver fibrosis, and hepatocellular carcinoma (HCC).

scholarly journals Assessing the Efficacy of Dietary Selenomethionine Supplementation in the Setting of Cardiac Ischemia/Reperfusion Injury

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 546 ◽  
Author(s):  
Leila Reyes ◽  
David P. Bishop ◽  
Clare L. Hawkins ◽  
Benjamin S. Rayner
Keyword(s):  
Cardiac Myocyte ◽  
Hypochlorous Acid ◽  
Ischemia Reperfusion Injury ◽  
Heart Function ◽  
Ischemia Reperfusion ◽  
Cytosolic Calcium ◽  
Cardiac Ischemia ◽  
Cellular Damage

Oxidative stress is a major hallmark of cardiac ischemia/reperfusion (I/R) injury. This partly arises from the presence of activated phagocytes releasing myeloperoxidase (MPO) and its production of hypochlorous acid (HOCl). The dietary supplement selenomethionine (SeMet) has been shown to bolster endogenous antioxidant processes as well as readily react with MPO-derived oxidants. The aim of this study was to assess whether supplementation with SeMet could modulate the extent of cellular damage observed in an in vitro cardiac myocyte model exposed to (patho)-physiological levels of HOCl and an in vivo rat model of cardiac I/R injury. Exposure of the H9c2 cardiac myoblast cell line to HOCl resulted in a dose-dependent increase in necrotic cell death, which could be prevented by SeMet supplementation and was attributed to SeMet preventing the HOCl-induced loss of mitochondrial inner trans-membrane potential, and the associated cytosolic calcium accumulation. This protection was credited primarily to the direct oxidant scavenging ability of SeMet, with a minor contribution arising from the ability of SeMet to bolster cardiac myoblast glutathione peroxidase (GPx) activity. In vivo, a significant increase in selenium levels in the plasma and heart tissue were seen in male Wistar rats fed a diet supplemented with 2 mg kg−1 SeMet compared to controls. However, SeMet-supplementation demonstrated only limited improvement in heart function and did not result in better heart remodelling following I/R injury. These data indicate that SeMet supplementation is of potential benefit within pathological settings where excessive HOCl is known to be generated but has limited efficacy as a therapeutic agent for the treatment of heart attack.

scholarly journals Catalase-Like Antioxidant Activity is Unaltered in Hypochlorous Acid Oxidized Horse Heart Myoglobin

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 414 ◽  
Author(s):  
Gulfam Ahmad ◽  
Belal Chami ◽  
Mary El Kazzi ◽  
Xiaosuo Wang ◽  
Maria Tereza S. Moreira ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Hypochlorous Acid ◽  
Cytochrome B5 ◽  
Oxidation Products ◽  
Oxygen Storage ◽  
Oxygen Binding ◽  
Tyrosyl Radical ◽  
Paramagnetic Resonance ◽  
Cytochrome B5 Reductase ◽  
Horse Heart Myoglobin

Activated neutrophils release myeloperoxidase that produces the potent oxidant hypochlorous acid (HOCl). Exposure of the oxygen transport protein horse heart myoglobin (hhMb) to HOCl inhibits Iron III (Fe(III))-heme reduction by cytochrome b5 to oxygen-binding Iron II (Fe(II))Mb. Pathological concentrations of HOCl yielded myoglobin oxidation products of increased electrophoretic mobility and markedly different UV/Vis absorbance. Mass analysis indicated HOCl caused successive mass increases of 16 a.m.u., consistent serial addition of molecular oxygen to the protein. By contrast, parallel analysis of protein chlorination by quantitative mass spectrometry revealed a comparatively minor increase in the 3-chlorotyrosine/tyrosine ratio. Pre-treatment of hhMb with HOCl affected the peroxidase reaction between the hemoprotein and H2O2 as judged by a HOCl dose-dependent decrease in spin-trapped tyrosyl radical detected by electron paramagnetic resonance (EPR) spectroscopy and the rate constant of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) oxidation. By contrast, Mb catalase-like antioxidant activity remained unchanged under the same conditions. Notably, HOCl-modification of Mb decreased the rate of ferric-to-ferrous Mb reduction by a cytochrome b5 reductase system. Taken together, these data indicate oxidizing HOCl promotes Mb oxidation but not chlorination and that oxidized Mb shows altered Mb peroxidase-like activity and diminished rates of one-electron reduction by cytochrome b5 reductase, possibly affecting oxygen storage and transport however, Mb-catalase-like antioxidant activity remains unchanged.

Sign in / Sign up

Export Citation Format

Share Document