scholarly journals Hydrogen Peroxide Induces Hyphal Differentiation in Candida albicans

2008 ◽  
Vol 7 (11) ◽  
pp. 2008-2011 ◽  
Author(s):  
Olviyani Nasution ◽  
Kavitha Srinivasa ◽  
Minsun Kim ◽  
Yeo-Jung Kim ◽  
Wankee Kim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Candida Albicans ◽  
Intracellular Concentration ◽  
Low Concentrations ◽  
Null Mutants

ABSTRACT In this study, we demonstrate that hyphal differentiation is induced by the subtoxic concentration of exogenous H2O2 in Candida albicans. This finding is confirmed by the changing intracellular concentration of H2O2. In order to induce the same level of differentiation, low concentrations of exogenous H2O2 are required for the null mutants of the thiol-specific antioxidant and catalase, while higher concentrations are needed for cells treated with ascorbic acid, an antioxidant chemical.

scholarly journals Deficiency of d-Erythroascorbic Acid Attenuates Hyphal Growth and Virulence of Candida albicans

2001 ◽  
Vol 69 (6) ◽  
pp. 3939-3946 ◽  
Author(s):  
Won-Ki Huh ◽  
Seong-Tae Kim ◽  
Hyungsoo Kim ◽  
Gajin Jeong ◽  
Sa-Ouk Kang
Keyword(s):  
Ascorbic Acid ◽  
Candida Albicans ◽  
Hyphal Growth ◽  
Multicopy Plasmid ◽  
Gene Encoding ◽  
Calculated Molecular Mass ◽  
Reading Frame ◽  
Functional Roles ◽  
Increased Sensitivity ◽  
Null Mutants

ABSTRACT In some lower eukaryotes, d-erythroascorbic acid, a five-carbon analog of l-ascorbic acid, is present instead of l-ascorbic acid. We have cloned ALO1, the gene encoding d-arabinono-1,4-lactone oxidase, which catalyzes the final step of d-erythroascorbic acid biosynthesis in Candida albicans. The ALO1 gene contained a continuous open reading frame of 1,671 bp that encodes a polypeptide consisting of 557 amino acids with a calculated molecular mass of 63,428 Da. To investigate the functional roles ofd-erythroascorbic acid in C. albicans, we disrupted or overexpressed the ALO1 gene. In thealo1/alo1 null mutants, the activity ofd-arabinono-1,4-lactone oxidase was completely lost andd-erythroascorbic acid could not be detected. WhenALO1 on a multicopy plasmid was transformed inC. albicans, the enzyme activity and the intracellulard-erythroascorbic acid level were increased up to 3.4-fold and 4.0-fold, respectively. The alo1/alo1 null mutants ofC. albicans showed increased sensitivity towards oxidative stress. Overexpression of ALO1 made the cells more resistant to the same stress. The alo1/alo1 mutants showed defective hyphal growth and attenuated virulence. Taken together, our results suggest that d-erythroascorbic acid functions as an important antioxidant and can be considered one of the virulence factors enhancing the pathogenicity of C. albicans.

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Trisodium Citrate ◽  
Synthesis And Characterization ◽  
Silver Nanoplates ◽  
Seed Mediated

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

Does microwave and hydrogen peroxide disinfection reduce Candida albicans biofilm on polymethyl methacrylate denture surfaces?

2021 ◽  
Author(s):  
Ilse Verónica Martínez-Serna ◽  
Marine Ortiz Magdaleno ◽  
Juan Antonio Cepeda-Bravo ◽  
Gabriel Fernando Romo-Ramírez ◽  
Luis Octavio Sánchez-Vargas
Keyword(s):  
Hydrogen Peroxide ◽  
Candida Albicans ◽  
Polymethyl Methacrylate

scholarly journals Monitoring the heme iron state in horseradish peroxidase to detect ultratrace amounts of hydrogen peroxide in alcohols

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9901-9910
Author(s):  
Raheleh Ravanfar ◽  
Alireza Abbaspourrad
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Oxidative Damage ◽  
Heme Iron ◽  
Aqueous Systems ◽  
Iron State ◽  
Low Concentrations

Despite the importance of hydrogen peroxide (H2O2) in initiating oxidative damage and its connection to various diseases, the detection of low concentrations of H2O2 (<10 μM) is still limited using current methods, particularly in non-aqueous systems.

scholarly journals Hormetic Concentrations of Hydrogen Peroxide but Not Ethanol Induce Cross-Adaptation to Different Stresses in Budding Yeast

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Halyna M. Semchyshyn
Keyword(s):  
Hydrogen Peroxide ◽  
Dose Response ◽  
Budding Yeast ◽  
Regulatory Protein ◽  
Colony Growth ◽  
Inhibitory Effect ◽  
Cross Resistance ◽  
Mild Stress ◽  
Low Concentrations ◽  
Cross Adaptation

The biphasic-dose response of microorganisms to hydrogen peroxide is a phenomenon of particular interest in hormesis research. In different animal models, the dose-response curve for ethanol is also nonlinear showing an inhibitory effect at high doses but a stimulatory effect at low doses. In this study, we observed the hormetic-dose response to ethanol in budding yeastS. cerevisiae. Cross-protection is a phenomenon in which exposure to mild stress results in the acquisition of cellular resistance to lethal stress induced by different factors. Since both hydrogen peroxide and ethanol at low concentrations were found to stimulate yeast colony growth, we evaluated the role of one substance in cell cross-adaptation to the other substance as well as some weak organic acid preservatives. This study demonstrates that, unlike ethanol, hydrogen peroxide at hormetic concentrations causes cross-resistance ofS. cerevisiaeto different stresses. The regulatory protein Yap1 plays an important role in the hormetic effects by low concentrations of either hydrogen peroxide or ethanol, and it is involved in the yeast cross-adaptation by low sublethal doses of hydrogen peroxide.

Effect of low concentrations of hydrogen peroxide on the contractile responses of rat detrusor smooth muscle strips

2010 ◽  
Vol 638 (1-3) ◽  
pp. 115-120 ◽  
Author(s):  
June Hyun Han ◽  
Moo Yeol Lee ◽  
Shin Young Lee ◽  
In Ho Chang ◽  
Hae Jong Kim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Smooth Muscle ◽  
Detrusor Smooth Muscle ◽  
Contractile Responses ◽  
Low Concentrations

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.

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