Redox Potential Difference between Desulfovibrio vulgaris and Clostridium beijerinckii Flavodoxins†

Biochemistry ◽  
2008 ◽  
Vol 47 (15) ◽  
pp. 4394-4402 ◽  
Author(s):  
Hiroshi Ishikita
Keyword(s):  
Redox Potential ◽  
Clostridium Beijerinckii ◽  
Potential Difference ◽  
Desulfovibrio Vulgaris

scholarly journals Exploring Coupled Redox and pH Processes with a Force Field-Based Approach: Applications to Five Different Systems

2020 ◽  
Author(s):  
Vinicius Cruzeiro ◽  
Gustavo Troiano Feliciano ◽  
Adrian Roitberg
Keyword(s):  
Force Field ◽  
Redox Potential ◽  
Desulfovibrio Vulgaris ◽  
Cytochrome C3 ◽  
Computational Tools ◽  
Redox States ◽  
Computational Performance ◽  
Redox Active ◽  
Constant Ph ◽  
Experimental Findings

Coupled redox and pH-driven processes are at the core of many important biological mechanisms. As the distribution of protonation and redox states in a system is associated with the pH and redox potential of the solution, having efficient computational tools that can simulate under these conditions become very important. Such tools have the potential to provide information that complement and drive experiments. In previous publications we have presented the implementation of the constant pH and redox potential molecular dynamics (C(pH,E)MD) method in AMBER and we have shown how multidimensional replica exchange can be used to significantly enhance the convergence efficiency of our simulations. In the current work, after an improvement in our C(pH,E)MD approach that allows a given residue to be simultaneously pH- and redox-active, we have employed our methodologies to study five different systems of interest in the literature. We present results for: capped tyrosine dipeptide, two maquette systems containing one pH- and redox-active tyrosine (α3Y and peptide A), and two proteins that contain multiple heme groups (diheme cytochrome c from Rhodobacter sphaeroides and Desulfovibrio vulgaris Hildenborough cytochrome c3). We show that our results can provide new insights into previous theoretical and experimental findings by using a fully force field-based and GPUaccelerated approach, which allows the simulations to be executed with high computational performance.

scholarly journals THe proton-per-electron stoicheiometry of ‘site 1’ of oxidative phosphorylation at high protonmotive force is close to 1.5

1982 ◽  
Vol 204 (2) ◽  
pp. 515-523 ◽  
Author(s):  
P C de Jonge ◽  
H V Westerhoff
Keyword(s):  
Redox Potential ◽  
Redox State ◽  
Dynamic Equilibrium ◽  
Experimental Situation ◽  
Potential Difference ◽  
Protonmotive Force ◽  
Submitochondrial Particles ◽  
Output Force ◽  
Group Translocation ◽  
Static Head

The maximum redox potential difference between the NAD+/NADH couple and the succinate/fumarate couple generated during ATP-energized reduction of NAD+ by succinate in submitochondrial particles was measured, together with the electrochemical potential difference for protons (delta mu approximately H+). The presence of cyanide, the time-independence of the redox potential difference and the irrelevance of the initial redox state of the NAD+/NADH couple ensured that the experimental situation corresponded to a ‘static-head condition’ with delta mu approximately H+ as the input force and the redox potential difference as the output force, the flow of electrons having reached dynamic equilibrium. Consequently, the observed value of 1.6 for the ratio delta Ge/delta mu approximately H+ is interpreted as indicating that the leads to H+/e- stoicheiometry at ‘site 1’ is 1.5 and that therefore the mechanism of the proton pump at ‘site 1’ is not of the group-translocation type (no direct leads to e - leads to H+ coupling).

Characterization of In-Core Water Chemistry for Corrosion Control of LWRs

2014 ◽  
Author(s):  
Genn Saji
Keyword(s):  
Redox Potential ◽  
Water Chemistry ◽  
Single Point ◽  
Experimental Results ◽  
Potential Difference ◽  
Corrosion Mechanism ◽  
Recent Theory ◽  
Scientific Validity ◽  
Pile Test ◽  
Test Loop

This paper updates scientific bases of water chemistry in applying the author’s recent theory, which integrates the elemental radiation- and electro-chemistry reactions in the “Butlar-Volmer equation,” presented in ICONE21-16525. For the past several years the author has been trying to establish that the “long-cell” (a kin to macro-cell) corrosion mechanism is inducing practically all sorts of accelerated corrosion phenomena widely observed in water-cooled reactors, especially in aged plants. The theoretical electrochemical potential differences have been benchmarked with the published in-pile test results for both PWR- and BWR water chemistry environments. However the author’s previous verification efforts were limited to the extent that the curves were fitted with experimental results at a single point. The author re-formulated the basic theory and found that the redox potential difference consists of an electrochemical part (e.g., Nernst equation of dissolved hydrogen or oxygen) and radiation-induced perturbation term, the latter diminishes to zero without radiation. The author continued his studies to clarify whether our current scientific knowledge is sufficient to explain the in-core “chemistry” to reproduce the experimental results without the fitting parameter. Through his study he realized that the basic mechanism of the potential difference is still not sufficiently known. No fitting parameter was used for the PWR water chemistry in the DH region for practical engineering applications, although it is indispensable to confirm the results with an in-pile test loop. In the BWR-NWC the theoretical redox potential out of core was still necessary to be fitted with the experimental results, due to an effect of residual hydrogen peroxide detected by the reference electrode. In addition the calculated potential shift is several times larger than the experimental observation. With the reformulation the scientific validity of the author’s theory is further confirmed. He believes that there is no doubt that the “long-cell” takes place in LWRs, although details are still debatable.

Syntheses, characterization and electrochemical and spectroscopic properties of ruthenium–iron complexes of 2,3,5,6-tetrakis(2-pyridyl)pyrazine and ferrocene-acetylide ligands

2016 ◽  
Vol 45 (26) ◽  
pp. 10620-10629 ◽  
Author(s):  
Hui-Min Wen ◽  
Jin-Yun Wang ◽  
Li-Yi Zhang ◽  
Lin-Xi Shi ◽  
Zhong-Ning Chen
Keyword(s):  
Redox Potential ◽  
Mixed Valence ◽  
Iron Complexes ◽  
Spectroscopic Properties ◽  
Potential Difference

A mixed-valence RuIIFeIII complex displays 0.50 V of redox potential difference induced by Ru⋯Fe interactions across the Ru–CC–Fc backbone and moderate IVCT band centered at 1247 nm.

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