Intramolecular Electrocatalysis of 8-Oxo-Guanine Oxidation:  Secondary Structure Control of Electron Transfer in Osmium-Labeled Oligonucleotides

2003 ◽  
Vol 42 (20) ◽  
pp. 6379-6387 ◽  
Author(s):  
Rebecca C. Holmberg ◽  
Mark T. Tierney ◽  
Patricia A. Ropp ◽  
Eric E. Berg ◽  
Mark W. Grinstaff ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Secondary Structure ◽  
Guanine Oxidation ◽  
Structure Control

Drastic promotion of guanine oxidation via electron transfer in Ψ-type DNA

2019 ◽  
Vol 55 (53) ◽  
pp. 7695-7698 ◽  
Author(s):  
Shunsuke Sakurai ◽  
Mayu Esumi ◽  
Makiko Tanaka
Keyword(s):  
Electron Transfer ◽  
Guanine Oxidation ◽  
Crowded Environment

Drastic promotion of guanine oxidation was induced by not only intraduplex ET but also interduplex ET in Ψ-type DNA in a crowded environment using PEG.

Molecular-structure control of electron transfer dynamics of push–pull porphyrins as sensitizers for NiO based dye sensitized solar cells

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77184-77194 ◽  
Author(s):  
Lei Zhang ◽  
Ludovic Favereau ◽  
Yoann Farre ◽  
Antoine Maufroy ◽  
Yann Pellegrin ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Electron Transfer ◽  
Solar Cells ◽  
Charge Separation ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Charge Recombination ◽  
Structure Control ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Zn(ii)-porphyrin dyes for NiO dye-sensitized solar cells showed surprisingly rapid charge recombination, in spite of their push–pull character. Appending a secondary acceptor prolonged charge separation and led to improved photovoltaic performance.

scholarly journals Thrombin-Binding Aptamer Quadruplex Formation: AFM and Voltammetric Characterization

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Victor Constantin Diculescu ◽  
Ana-Maria Chiorcea-Paquim ◽  
Ramon Eritja ◽  
Ana Maria Oliveira-Brett
Keyword(s):  
Electron Transfer ◽  
Surface Coverage ◽  
Pyrolytic Graphite ◽  
Oxidation Potential ◽  
Oxidation Peak ◽  
No Adsorption ◽  
Guanine Oxidation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Quadruplex Formation

The adsorption and the redox behaviour of thrombin-binding aptamer (TBA) and extended TBA (eTBA) were studied using atomic force microscopy and voltammetry at highly oriented pyrolytic graphite and glassy carbon. The different adsorption patterns and degree of surface coverage were correlated with the sequence base composition, presence/absence of K+, and voltammetric behaviour of TBA and eTBA. In the presence of K+, only a few single-stranded sequences present adsorption, while the majority of the molecules forms stable and rigid quadruplexes with no adsorption. Both TBA and eTBA are oxidized and the only anodic peak corresponds to guanine oxidation. Upon addition of K+ions, TBA and eTBA fold into a quadruplex, causing the decrease of guanine oxidation peak and occurrence of a new peak at a higher potential due to the oxidation of G-quartets. The higher oxidation potential of G-quartets is due to the greater difficulty of electron transfer from the inside of the quadruplex to the electrode surface than electron transfer from the more flexible single strands.

Inhibiting guanine oxidation and enhancing the excess-electron-transfer efficiency of a pyrene-modified oligonucleotide by introducing an electron-donating group on pyrene

2019 ◽  
Vol 55 (93) ◽  
pp. 14062-14065 ◽  
Author(s):  
Takumi Okuda ◽  
Yusuke Kawashima ◽  
Yuuya Kasahara ◽  
Tatsuya Takagi ◽  
Junpei Yamamoto ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excess Electron ◽  
Transfer Efficiency ◽  
Guanine Oxidation ◽  
Mediated Electron Transfer ◽  
Reduction Efficiency ◽  
Modified Oligonucleotide

PipPyU and OMePyU enhance the reduction efficiency without oxidizing guanine in DNA-mediated electron transfer.

Attenuation of guanine oxidation via DNA-mediated electron transfer in a crowded environment using small cosolutes

2018 ◽  
Vol 16 (36) ◽  
pp. 6695-6702 ◽  
Author(s):  
Makiko Tanaka ◽  
Takayuki Matsumoto ◽  
Hiroki Iida
Keyword(s):  
Electron Transfer ◽  
Molecular Crowding ◽  
Guanine Oxidation ◽  
Mediated Electron Transfer ◽  
Modified Oligonucleotide ◽  
Crowded Environment

Guanine oxidation induced by photoirradiation on a pyrene-modified oligonucleotide was investigated under molecular crowding using small cosolutes such as glycerol.

scholarly journals The Influence of Secondary Structure on Electron Transfer in Peptides

2013 ◽  
Vol 66 (8) ◽  
pp. 848 ◽  
Author(s):  
Jingxian Yu ◽  
John R. Horsley ◽  
Andrew D. Abell
Keyword(s):  
Electron Transfer ◽  
Secondary Structure ◽  
Chain Length ◽  
Intramolecular Hydrogen Bonding ◽  
Electrochemical Analysis ◽  
Helical Conformation ◽  
Intramolecular Electron Transfer ◽  
Helical Structures ◽  
Redox Active ◽  
Intramolecular Hydrogen

A series of synthetic peptides containing 0–5 α-aminoisobutyric acid (Aib) residues and a C-terminal redox-active ferrocene was synthesised and their conformations defined by NMR and circular dichroism. Each peptide was separately attached to an electrode for subsequent electrochemical analysis in order to investigate the effect of peptide chain length (distance dependence) and secondary structure on the mechanism of intramolecular electron transfer. While the shorter peptides (0–2 residues) do not adopt a well defined secondary structure, the longer peptides (3–5 residues) adopt a helical conformation, with associated intramolecular hydrogen bonding. The electrochemical results on these peptides clearly revealed a transition in the mechanism of intramolecular electron transfer on transitioning from the ill-defined shorter peptides to the longer helical peptides. The helical structures undergo electron transfer via a hopping mechanism, while the shorter ill-defined structures proceeded via an electron superexchange mechanism. Computational studies on two β-peptides PCB-(β3Val-β3Ala-β3Leu)n–NHC(CH3)2OOtBu (n = 1 and 2; PCB = p-cyanobenzamide) were consistent with these observations, where the n = 2 peptide adopts a helical conformation and the n = 1 peptide an ill-defined structure. These combined studies suggest that the mechanism of electron transfer is defined by the extent of secondary structure, rather than merely chain length as is commonly accepted.

ChemInform Abstract: The Influence of Secondary Structure on Electron Transfer in Peptides

ChemInform ◽  
2013 ◽  
Vol 44 (45) ◽  
pp. no-no
Author(s):  
Jingxian Yu ◽  
John R. Horsley ◽  
Andrew D. Abell
Keyword(s):  
Electron Transfer ◽  
Secondary Structure

scholarly journals Amino Acid Substitutions in the Non-Ordered Ω-Loop 70–85 Affect Electron Transfer Function and Secondary Structure of Mitochondrial Cytochrome c

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 973
Author(s):  
Rita V. Chertkova ◽  
Tatyana V. Bryantseva ◽  
Nadezhda A. Brazhe ◽  
Kseniya S. Kudryashova ◽  
Victor V. Revin ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Secondary Structure ◽  
Cytochrome C ◽  
Cd Spectroscopy ◽  
Mitochondrial Cytochrome ◽  
Proposed Model ◽  
Donor And Acceptor ◽  
Cytochromes C ◽  
Spectroscopy Studies ◽  
Mitochondrial Cytochrome C

The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-loop, exhibiting reduced efficiency of electron transfer, were studied. CD spectroscopy studies showed that the ordering of mutant structure increases by 3–6% compared to that of the WT molecules due to the higher content of β-structural elements. The IR spectroscopy data are consistent with the CD results and demonstrate that some α-helical elements change into β-structures, and the amount of the non-structured elements is decreased. The analysis of the 1H-NMR spectra demonstrated that cytochrome c mutants have a well-determined secondary structure with some specific features related to changes in the heme microenvironment. The observed changes in the structure of cytochrome c mutants are likely to be responsible for the decrease in the conformational mobility of the P76GTKMIFA83 sequence carrying mutations and for the decline in succinate:cytochrome c-reductase and cytochrome c-oxidase activities in the mitoplast system in the presence of these cytochromes c. We suggest that the decreased efficiency of the electron transfer of the studied cytochromes c may arise due to: (1) the change in the protein conformation in sites responsible for the interaction of cytochrome c with complexes III and IV and (2) the change in the heme conformation that deteriorates its optimal orientation towards donor and acceptor in complexes III and IV therefore slows down electron transfer. The results obtained are consistent with the previously proposed model of mitochondrial cytochrome c functioning associated with the deterministic mobility of protein globule parts.

Shortcuts for Electron‐Transfer through the Secondary Structure of Helical Oligo‐1,2‐Naphthylenes

2019 ◽  
Vol 25 (72) ◽  
pp. 16748-16754 ◽  
Author(s):  
Alessandro Castrogiovanni ◽  
Patrick Herr ◽  
Christopher B. Larsen ◽  
Xingwei Guo ◽  
Christof Sparr ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Secondary Structure
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