scholarly journals Evolving stability and pH-dependent activity of the high redox potential Botrytis aclada laccase for enzymatic fuel cells

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Stefan Scheiblbrandner ◽  
Erik Breslmayr ◽  
Florian Csarman ◽  
Regina Paukner ◽  
Johannes Führer ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Redox Potential ◽  
Dependent Activity ◽  
Ph Dependent ◽  
High Redox Potential

A few key residues determine the high redox potential shift in azurin mutants

2015 ◽  
Vol 13 (45) ◽  
pp. 11003-11013 ◽  
Author(s):  
Laura Zanetti-Polzi ◽  
Carlo A. Bortolotti ◽  
Isabella Daidone ◽  
Massimiliano Aschi ◽  
Andrea Amadei ◽  
...  
Keyword(s):  
Redox Potential ◽  
Potential Shift ◽  
Key Residues ◽  
High Redox Potential

The changes in the redox potential of Azurin upon mutation stem from the effects of a few key residues, including non-mutated ones, rather than being the result of a generalized rearrangement.

scholarly journals Purification and Partial Characterization of a Thermostable Laccase from Pycnoporus sanguineus CS-2 with Ability to Oxidize High Redox Potential Substrates and Recalcitrant Dyes

10.5772/56374 ◽  
2013 ◽  
Author(s):  
Sergio M. Salcedo Martnez ◽  
Guadalupe Gutirrez-Soto ◽  
Carlos F. Rodriguez Garza ◽  
Tania J. Villarreal Galvan ◽  
Juan F. Contreras Cordero ◽  
...  
Keyword(s):  
Redox Potential ◽  
Partial Characterization ◽  
Pycnoporus Sanguineus ◽  
High Redox Potential

scholarly journals Electrochemically Induced Metal- vs. Ligand-Based Redox Changes in Mackinawite: Identification of a Fe3+- and Polysulfide-Containing Intermediate

2021 ◽  
Author(s):  
Sebastian Sanden ◽  
Robert Szilagyi ◽  
Yamei Li ◽  
Norio Kitadai ◽  
Samuel M Webb ◽  
...  
Keyword(s):  
Redox Potential ◽  
Ferrous Iron ◽  
Maturation Process ◽  
Anaerobic Conditions ◽  
Ph Dependent

Under anaerobic conditions, ferrous iron reacts with sulfide producing FeS, which can then undergo a temperature, redox potential, and pH dependent maturation process resulting in the formation of oxidized mineral...

scholarly journals Titanium-based potassium-ion battery positive electrode with extraordinarily high redox potential

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Stanislav S. Fedotov ◽  
Nikita D. Luchinin ◽  
Dmitry A. Aksyonov ◽  
Anatoly V. Morozov ◽  
Sergey V. Ryazantsev ◽  
...  
Keyword(s):  
Redox Potential ◽  
Potassium Ion ◽  
Positive Electrode ◽  
High Redox Potential

scholarly journals Characterization of a Histidine Containing Antimicrobial Peptide with pH Dependent Activity

2019 ◽  
Vol 116 (3) ◽  
pp. 83a ◽  
Author(s):  
Luis Santiago-Ortiz ◽  
Morgan Hitchner ◽  
Thaddeus Palmer ◽  
Gregory A. Caputo
Keyword(s):  
Antimicrobial Peptide ◽  
Dependent Activity ◽  
Ph Dependent

The effect of pH and complexation on redox reactions between RS• radicals and flavins

1984 ◽  
Vol 62 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Redox Potential ◽  
Linear Function ◽  
Redox Reactions ◽  
Flavin Adenine Dinucleotide ◽  
Protonated Form ◽  
Redox Properties ◽  
The Other ◽  
Effect Of Ph ◽  
Other Hand ◽  
High Redox Potential

Elementary considerations indicate that thiol radicals, RS•, should have a high redox potential [Formula: see text][Formula: see text]However, the equilibrium [4],[Formula: see text]which is established in the presence of excess RS−, would convert RS•to [Formula: see text] which is a reducing species. Experimentally it was demonstrated that thiol radicals made by γ radiolysis of β-mercaptoethanol solutions effected two-electron oxidation of dihydroflavin FlH2 at pH 6.3 and of FlH− at pH 8. On the other hand, [Formula: see text] readily reduced Fl to FlH2 or FlH− as expected. At pH 9, photostationary states were established after a few minutes radiolysis and the ratios [FlH−]ss/[Fl]ss were a function of [Formula: see text] The main reactions occurring were:[Formula: see text]The values of k19 and k22 were both large. The ratio k19/k22 was ∼0.8 for lumiflavin and ∼0.3 for flavin adenine dinucleotide. The cyclic disulphide anions of lipoamide and dithiothreitol [Formula: see text] also effected two-electron reductions of flavins. However, the protonated form of [Formula: see text] oxidized FlH2, and the photostationary ratio [FlH−]ss/[Fl]ss was an approximate linear function of [Formula: see text]. The implications of the observed changes in redox properties of sulphur radicals on complexation with RS− and protonation were briefly considered.Des considérations élémentaires indiquent que les radicaux thiyles, RS•, doivent avoir un potentiel rédox élevé [Formula: see text][Formula: see text]

scholarly journals A systematic approach to study the pH-dependent release, productivity and product specificity of dextransucrases

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Jonas Schmid ◽  
Julia Bechtner ◽  
Rudi F. Vogel ◽  
Frank Jakob
Keyword(s):  
Extracellular Enzymes ◽  
Methodological Approach ◽  
Reaction Conditions ◽  
Product Specificity ◽  
Ph Values ◽  
Gelling Properties ◽  
Dependent Activity ◽  
Ph Dependent ◽  
The Stability ◽  
Extracellular Environment

Abstract Background Dextransucrases are extracellular enzymes, which catalyze the formation of α-1→6-linked glucose polymers from sucrose. These enzymes are exclusively expressed by lactic acid bacteria, which commonly acidify the extracellular environment due to their physiology. Dextransucrases are thus confronted with steadily changing reaction conditions in regards to the environmental pH, which can further affect the amount of released dextransucrases. In this work, we studied the effect of the environmental pH on the release, the productivity and the product specificity of the dextransucrase expressed by Lactobacillus (L.) hordei TMW 1.1822. Dextransucrases were recovered as crude extracts at pH 3.5–pH 6.5 and then again used to produce dextrans at these pH values. The respectively produced dextran amounts and sizes were determined and the obtained results finally systematically correlated. Results Maximum dextran amounts were produced at pH 4.0 and pH 4.5, while the productivity of the dextransucrases significantly decreased at pH 3.5 and pH 6.5. The distribution of dextran amounts produced at different pH most likely reflects the pH dependent activity of the dextransucrases released by L. hordei, since different transglycosylation rates were determined at different pH using the same dextransucrase amounts. Moreover, similar hydrolysis activities were detected at all tested conditions despite significant losses of transglycosylation activities indicating initial hydrolysis prior to transglycosylation reactions. The molar masses and rms radii of dextrans increased up to pH 5.5 independently of the stability of the enzyme. The gelling properties of dextrans produced at pH 4.0 and pH 5.5 were different. Conclusions The presented methodological approach allows the controlled production of dextrans with varying properties and could be transferred and adapted to other microbes for systematic studies on the release and functionality of native sucrases or other extracellular enzymes.

Sign in / Sign up

Export Citation Format

Share Document