scholarly journals Contribution of the stereospecific methionine sulphoxide reductases MsrA and MsrB to oxidative and nitrosative stress resistance in the food-borne pathogen Campylobacter jejuni

Microbiology ◽  
2008 ◽  
Vol 154 (8) ◽  
pp. 2219-2230 ◽  
Author(s):  
John M. Atack ◽  
David J. Kelly
Keyword(s):  
Campylobacter Jejuni ◽  
Stress Resistance ◽  
Nitrosative Stress ◽  
Oxidative And Nitrosative Stress ◽  
Food Borne

scholarly journals Isocitrate Dehydrogenase Is Important for Nitrosative Stress Resistance in Cryptococcus neoformans, but Oxidative Stress Resistance Is Not Dependent on Glucose-6-Phosphate Dehydrogenase

2010 ◽  
Vol 9 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Sarah M. Brown ◽  
Rajendra Upadhya ◽  
James D. Shoemaker ◽  
Jennifer K. Lodge
Keyword(s):  
Oxidative Stress ◽  
Cryptococcus Neoformans ◽  
Stress Resistance ◽  
Isocitrate Dehydrogenase ◽  
Nitrosative Stress ◽  
Stress Sensitivity ◽  
Wild Type ◽  
Oxidative And Nitrosative Stress ◽  
Content Type ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT The opportunistic intracellular fungal pathogen Cryptococcus neoformans depends on many antioxidant and denitrosylating proteins and pathways for virulence in the immunocompromised host. These include the glutathione and thioredoxin pathways, thiol peroxidase, cytochrome c peroxidase, and flavohemoglobin denitrosylase. All of these ultimately depend on NADPH for either catalytic activity or maintenance of a reduced, functional form. The need for NADPH during oxidative stress is well established in many systems, but a role in resistance to nitrosative stress has not been as well characterized. In this study we investigated the roles of two sources of NADPH, glucose-6-phosphate dehydrogenase (Zwf1) and NADP+-dependent isocitrate dehydrogenase (Idp1), in production of NADPH and resistance to oxidative and nitrosative stress. Deletion of ZWF1 in C. neoformans did not result in an oxidative stress sensitivity phenotype or changes in the amount of NADPH produced during oxidative stress compared to those for the wild type. Deletion of IDP1 resulted in greater sensitivity to nitrosative stress than to oxidative stress. The amount of NADPH increased 2-fold over that in the wild type during nitrosative stress, and yet the idp1Δ strain accumulated more mitochondrial damage than the wild type during nitrosative stress. This is the first report of the importance of Idp1 and NADPH for nitrosative stress resistance.

scholarly journals A truncated haemoglobin implicated in oxygen metabolism by the microaerophilic food-borne pathogen Campylobacter jejuni

Microbiology ◽  
2005 ◽  
Vol 151 (12) ◽  
pp. 4079-4091 ◽  
Author(s):  
Laura M. Wainwright ◽  
Karen T. Elvers ◽  
Simon F. Park ◽  
Robert K. Poole
Keyword(s):  
Campylobacter Jejuni ◽  
Nitrosative Stress ◽  
Bacterial Pathogen ◽  
Oxygen Metabolism ◽  
Wild Type ◽  
Gene Encoding ◽  
Food Borne ◽  
Micro Organisms ◽  
Mutant Cells ◽  
Kinetics Of

Of the three groups of haemoglobins identified in micro-organisms (single-domain globins, flavohaemoglobins and truncated globins), the last group is the least well understood. The function of the truncated haemoglobin (Ctb) encoded by Cj0465c in the microaerophilic food-borne bacterial pathogen Campylobacter jejuni was investigated by constructing a ctb mutant and characterizing its phenotype. The effects of the ctb mutation on the kinetics of terminal oxidase function in C. jejuni were investigated using oxyleghaemoglobin and oxymyoglobin as sensitive reporters of O2 consumption. The V max of ctb mutant cells for O2, calculated using either globin, was greater than that of wild-type cells at extracellular O2 concentrations up to ∼1 μM, suggesting a role for Ctb in moderating O2 supply for reduction by high-affinity terminal oxidases. However, cells mutated in ctb were disadvantaged when grown under conditions of high aeration, as revealed by measurements of growth yields and rates in batch culture. Furthermore, the rate at which ctb mutant cells consumed O2 in an O2 electrode (10–200 μM O2) was approximately half the rate displayed by wild-type cells, reflecting a role for Ctb in respiration at physiologically relevant external O2 concentrations. However, a lack of sensitivity of the mutant to paraquat or H2O2 indicated that increased oxidative stress under such conditions was not the cause of these phenotypes. O2 affinities of cells (K m values of approximately 40 nM and 1 μM) were unaffected by mutation of either Ctb or the full-length C. jejuni globin, Cgb. Although the gene encoding Ctb was found to be upregulated by S-nitrosoglutathione (GSNO) and the NO-donating compound S-nitroso-N-acetylpenicillamine (SNAP), a ctb mutant did not display sensitivity to a number of nitrosative stress-generating compounds. The authors conclude that Ctb is involved in moderating O2 flux within C. jejuni.

The role of a 2-on-2 haemoglobin in oxidative and nitrosative stress resistance of Antarctic Pseudoalteromonas haloplanktis TAC125

Biochimie ◽  
2010 ◽  
Vol 92 (8) ◽  
pp. 1003-1009 ◽  
Author(s):  
Ermenegilda Parrilli ◽  
Maria Giuliani ◽  
Daniela Giordano ◽  
Roberta Russo ◽  
Gennaro Marino ◽  
...  
Keyword(s):  
Stress Resistance ◽  
Nitrosative Stress ◽  
Oxidative And Nitrosative Stress ◽  
Pseudoalteromonas Haloplanktis ◽  
Pseudoalteromonas Haloplanktis Tac125

scholarly journals Microbes use encapsulin protein organelles to sequester toxic reactions

2016 ◽  
Author(s):  
Tobias W. Giessen ◽  
Pamela A. Silver
Keyword(s):  
Stress Resistance ◽  
Iron Homeostasis ◽  
Nitrosative Stress ◽  
Carbon Fixation ◽  
Ammonium Oxidation ◽  
Ecological Processes ◽  
Oxidative And Nitrosative Stress ◽  
Toxic Reaction ◽  
Cargo Proteins ◽  
Toxic Reactions

AbstractCells organize and regulate their metabolism via membrane-or protein-bound organelles. In this way, incompatible processes can be spatially separated and controlled. In prokaryotes, protein-based compartments are used to sequester harmful reactions and store useful compounds. These protein compartments play key roles in various metabolic and ecological processes ranging from iron homeostasis to carbon fixation. We identified more than 900 proteinaceous encapsulin nanocompartment systems in bacterial and archaeal genomes. Encapsulins can be found in 15 bacterial and 2 archaeal phyla. Our analysis reveals 1 new capsid type and 9 previously unknown cargo proteins targeted to the interior of encapsulins. We experimentally characterize 3 newly identified encapsulin systems and illustrate their involvement in iron mineralization, oxidative and nitrosative stress resistance and anaerobic ammonium oxidation, a process responsible for 30% of the N lost from the oceans. We propose that encapsulins represent a widespread strategy for toxic reaction sequestration in prokaryotes.

scholarly journals Myeloperoxidase-Related Chlorination Activity Is Positively Associated with Circulating Ceruloplasmin in Chronic Heart Failure Patients: Relationship with Neurohormonal, Inflammatory, and Nutritional Parameters

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Aderville Cabassi ◽  
Simone Maurizio Binno ◽  
Stefano Tedeschi ◽  
Gallia Graiani ◽  
Cinzia Galizia ◽  
...  
Keyword(s):  
Heart Failure ◽  
Nitrosative Stress ◽  
Defense Mechanism ◽  
Nyha Class ◽  
Protein Nitration ◽  
Class Iii ◽  
Oxidative And Nitrosative Stress ◽  
Radical Production ◽  
Antioxidant Function ◽  
The Relationship

Rationale. Heart failure (HF) is accompanied by the development of an imbalance between oxygen- and nitric oxide-derived free radical production leading to protein nitration. Both chlorinating and peroxidase cycle of Myeloperoxidase (MPO) contribute to oxidative and nitrosative stress and are involved in tyrosine nitration of protein. Ceruloplasmin (Cp) has antioxidant function through its ferroxidase I (FeOxI) activity and has recently been proposed as a physiological defense mechanism against MPO inappropriate actions.Objective. We investigated the relationship between plasma MPO-related chlorinating activity, Cp and FeOxI, and nitrosative stress, inflammatory, neurohormonal, and nutritional biomarkers in HF patients.Methods and Results. In chronic HF patients (n=81, 76±9 years, NYHA Class II (26); Class III (29); Class IV (26)) and age-matched controls (n=17, 75±11 years, CTR), plasma MPO chlorinating activity, Cp, FeOxI, nitrated protein, free Malondialdehyde, BNP, norepinephrine, hsCRP, albumin, and prealbumin were measured. Plasma MPO chlorinating activity, Cp, BNP, norepinephrine, and hsCRP were increased in HF versus CTR. FeOxI, albumin, and prealbumin were decreased in HF. MPO-related chlorinating activity was positively related to Cp (r= 0.363,P<0.001), nitrated protein, hsCRP, and BNP and inversely to albumin.Conclusions. Plasma MPO chlorinated activity is increased in elderly chronic HF patients and positively associated with Cp, inflammatory, neurohormonal, and nitrosative parameters suggesting a role in HF progression.

scholarly journals Methane and Inflammation - A Review (Fight Fire with Fire)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Marietta Zita Poles ◽  
László Juhász ◽  
Mihály Boros
Keyword(s):  
Stress Responses ◽  
Nitrosative Stress ◽  
Ischemia Reperfusion ◽  
Signalling Pathways ◽  
Experimental Conditions ◽  
Neuroprotective Effects ◽  
Oxidative And Nitrosative Stress ◽  
Carbohydrate Fermentation ◽  
Insight Into

AbstractMammalian methanogenesis is regarded as an indicator of carbohydrate fermentation by anaerobic gastrointestinal flora. Once generated by microbes or released by a non-bacterial process, methane is generally considered to be biologically inactive. However, recent studies have provided evidence for methane bioactivity in various in vivo settings. The administration of methane either in gas form or solutions has been shown to have anti-inflammatory and neuroprotective effects in an array of experimental conditions, such as ischemia/reperfusion, endotoxemia and sepsis. It has also been demonstrated that exogenous methane influences the key regulatory mechanisms and cellular signalling pathways involved in oxidative and nitrosative stress responses. This review offers an insight into the latest findings on the multi-faceted organ protective activity of exogenous methane treatments with special emphasis on its versatile effects demonstrated in sepsis models.

scholarly journals Cellular Responses of Candida albicans to Phagocytosis and the Extracellular Activities of Neutrophils Are Critical to Counteract Carbohydrate Starvation, Oxidative and Nitrosative Stress

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e52850 ◽  
Author(s):  
Pedro Miramón ◽  
Christine Dunker ◽  
Hanna Windecker ◽  
Iryna M. Bohovych ◽  
Alistair J. P. Brown ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Nitrosative Stress ◽  
Cellular Responses ◽  
Oxidative And Nitrosative Stress ◽  
Carbohydrate Starvation
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