Project description:Escherichia coli culture was subjected to two different types of nutritional scenarios, abundant carbon/ nitrogen sources and scarce carbon/nitrogen medium. Study revealed that scarce medium adapted culture were more tolerant to hydrogen peroxide than abundant medium.
Project description:Fast photochemical oxidation of proteins (FPOP) is a hydroxyl radical protein footprinting method that covalently labels solvent accessible amino acids by photolysis of hydrogen peroxide. Recently, we expanded the use of FPOP for in vivo (IV-FPOP) covalent labeling in C. elegans. In initial IV-FPOP studies, 545 proteins were oxidatively modified in all body systems within the worm. Here, with the use of chemical penetration enhancers (CPEs), we increased the number of modified proteins as well as the number of modifications per protein to gain increased structural information. CPEs aid in the delivery of hydrogen peroxide inside C. elegans by disturbing the highly order lipid bilayer of the worm cuticle without affecting worm viability. IV-FPOP experiments performed using the CPE azone showed an increase in oxidatively modified proteins and peptides. This increase correlated with greater hydrogen peroxide uptake by C. elegans quantified using a chemical fluorophore demonstrating the efficacy of using CPEs with IV-FPOP.
2020-06-12 | PXD019290 | Pride
Project description:Biochar modified overburden synergistically reduces methane and hydrogen sulfide
Project description:This model is described in the article:
The mechanism of catalase action. II. Electric analog computer studies.
Britton Chance, David S Greenstein, Joseph Higgins, CC Yang, Arch Biochem. 1952 37:322-39. PubmedID:14953444
Summary:
An electric analog computer has been constructed for a study of the kinetics of catalase action. This computer gives results for the formation and disappearance of the catalase-hydrogen peroxide complex that are in good agreement with the experimental data. The computer study verifies an approximate method for the computation of the velocity constant for the combination of hydrogen peroxide and catalase and justifies the simple formula used previously to compute the velocity constant for the reaction of the catalase-hydrogen peroxide complex with donor molecules. Finally, the computer data show that the binding of peroxide to catalase is a practically irreversible reaction.
The reaction of the enzyme-substrate complex, p, with the electron donor, a, is bimolecular, although in the article, as a is assumed to be constant, it is modelled using an apparent rate constant consisting of the product of the rate constant, k4, and the concentration of a. In this implementation, the concentration of a is set to 1 and the value of k4 just adapted so that the product equals the values given for k4*a in the article. The specific parameter values are taken from Fig 3. The graphs do not exactly match those in the paper, this may be due to the different simulators used.
Project description:Reactive oxygen species such as hydrogen peroxide occur in all aerobically living organisms. Oxidative stress during fermentation can impair the fitness of the production host and the quality of the product. B. pumilus has been described as highly resistant to hydrogen peroxide. The response of exponentially growing B. pumilus cells to hydrogen peroxide was studied.
Project description:The transcriptomic response of Jurkat T lymphoma cells to hydrogen peroxide was investigated to determine the global effects of hydrogen peroxide on cellular gene expression.
Project description:Acinetobacter baumannii is a Gram-negative opportunistic pathogen that causes multiple infections, including pneumonia, bacteremia, and wound infections. Due to multiple intrinsic and acquired drug-resistance mechanisms, A. baumannii isolates are commonly multi-drug resistant and infections are notoriously difficult to treat. Therefore, it is important to identify mechanisms used by A. baumannii to survive stresses encountered during infection as a means of identifying new drug targets. In this study, we determined the transcriptional response of A. baumannii to hydrogen peroxide stress using RNASequencing. Upon exposure to hydrogen peroxide, A. baumannii differentially transcribes several hundred genes. In this study, we also determined the transcriptional profile of A. baumannii strains with the transcriptional regulators mumR or oxyR genetically inactivated and identified transcriptional differences between these strains and wild-type A. baumannii in response to hydrogen peroxide stress. In doing this, the function of A. baumannii OxyR in hydrogen peroxide stress resistance and regulation of genes required for hydrogen peroxide detoxification was defined. Moreover, the contribution of the uncharacterized regulator MumR to hydrogen peroxide stress resistance was also explored. This work reveals the transcriptome of an important human pathogen in the presence of hydrogen peroxide stress.
Project description:We report 293 Neisseria gonorrhoeae genes that show differential transcript abundance in response to 15 mM hydrogen peroxide treatment by RNA-Seq. We analyze the major physiological functional groups of genes affected by hydrogen peroxide exposure. In addition, we analyze which genes in our hydrogen peroxide-responsive set of genes belong to major known transcriptional regulatory circuits like iron homeostasis, anaerobiosis and others. We annotate which of the 293 hydrogen peroxide-responsive genes belong to operons. We annotate global transcriptional start sites and identify transcriptional start sites that are only present in hydrogen peroxide-treated bacteria. We validate the RNA-Seq data for a subset of representative genes by RT-qPCR and whether transcript abundance in this same subset of genes differs upon treatement with other reactive oxygen species encountered during infection, like organic peroxide, super oxide anion, and bleach.
Project description:Transcriptional profiling of HMB-treated (24h) differentiating equine satellite cells (3rd day of differentiation) exposed to hydrogen peroxide (1h; last hour of pre-incubation with HMB) compared to control HMB-untreated cells. Goal was to determine the effects of HMB pre-incubation on miRNA expression in equine satellite cells exposed to hydrogen peroxide.
Project description:Transcriptional profiling of GO-treated (24h) differentiating equine satellite cells (3rd day of differentiation) exposed to hydrogen peroxide (1h; last hour of pre-incubation with GO) compared to control GO-untreated cells. Goal was to determine the effects of GO pre-incubation on miRNA expression in equine satellite cells exposed to hydrogen peroxide.