pH-Response Mechanism of a Redox Reaction between Silver Ions and Hydroquinone

2016 ◽  
Vol 120 (40) ◽  
pp. 23104-23110 ◽  
Author(s):  
Tao Xie ◽  
Chao Jing ◽  
Meng Li ◽  
Wei Ma ◽  
Zhifeng Ding ◽  
...  
Keyword(s):  
Redox Reaction ◽  
Silver Ions ◽  
Response Mechanism ◽  
Ph Response

scholarly journals Inhibition of oxygen dimerization by local symmetry tuning in Li-rich layered oxides for improved stability

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Fanghua Ning ◽  
Biao Li ◽  
Jin Song ◽  
Yuxuan Zuo ◽  
Huaifang Shang ◽  
...  
Keyword(s):  
Redox Reaction ◽  
High Capacity ◽  
Structural Response ◽  
Lithium Ion ◽  
Local Symmetry ◽  
Oxygen Release ◽  
Response Mechanism ◽  
Layered Oxides ◽  
Improved Stability ◽  
Further Development

Abstract Li-rich layered oxide cathode materials show high capacities in lithium-ion batteries owing to the contribution of the oxygen redox reaction. However, structural accommodation of this reaction usually results in O–O dimerization, leading to oxygen release and poor electrochemical performance. In this study, we propose a new structural response mechanism inhibiting O–O dimerization for the oxygen redox reaction by tuning the local symmetry around the oxygen ions. Compared with regular Li2RuO3, the structural response of the as-prepared local-symmetry-tuned Li2RuO3 to the oxygen redox reaction involves the telescopic O–Ru–O configuration rather than O–O dimerization, which inhibits oxygen release, enabling significantly enhanced cycling stability and negligible voltage decay. This discovery of the new structural response mechanism for the oxygen redox reaction will provide a new scope for the strategy of enhancing the anionic redox stability, paving unexplored pathways toward further development of high capacity Li-rich layered oxides.

scholarly journals The molecular pH-response mechanism of the plant light-stress sensor PsbS

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maithili Krishnan-Schmieden ◽  
Patrick E. Konold ◽  
John T. M. Kennis ◽  
Anjali Pandit
Keyword(s):  
Protein Interactions ◽  
Physcomitrella Patens ◽  
Light Stress ◽  
Ph Sensor ◽  
Low Ph ◽  
Molecular Response ◽  
Response Mechanism ◽  
Ph Response ◽  
Excess Light ◽  
Shared Motif

AbstractPlants need to protect themselves from excess light, which causes photo-oxidative damage and lowers the efficiency of photosynthesis. Photosystem II subunit S (PsbS) is a pH sensor protein that plays a crucial role in plant photoprotection by detecting thylakoid lumen acidification in excess light conditions via two lumen-faced glutamates. However, how PsbS is activated under low-pH conditions is unknown. To reveal the molecular response of PsbS to low pH, here we perform an NMR, FTIR and 2DIR spectroscopic analysis of Physcomitrella patens PsbS and of the E176Q mutant in which an active glutamate has been replaced. The PsbS response mechanism at low pH involves the concerted action of repositioning of a short amphipathic helix containing E176 facing the lumen and folding of the luminal loop fragment adjacent to E71 to a 310-helix, providing clear evidence of a conformational pH switch. We propose that this concerted mechanism is a shared motif of proteins of the light-harvesting family that may control thylakoid inter-protein interactions driving photoregulatory responses.

Electronic Structure and Solvation of Copper and Silver Ions: A Theoretical Picture of a Model Aqueous Redox Reaction

ChemInform ◽  
2004 ◽  
Vol 35 (23) ◽  
Author(s):  
Jochen Blumberger ◽  
Leonardo Bernasconi ◽  
Ivano Tavernelli ◽  
Rodolphe Vuilleumier ◽  
Michiel Sprik
Keyword(s):  
Electronic Structure ◽  
Redox Reaction ◽  
Silver Ions

scholarly journals The two active glutamates of the plant stress sensor PsbS contribute non-equivalently to its pH-activated molecular response mechanism

2018 ◽  
Author(s):  
Maithili Krishnan ◽  
Patrick E. Konold ◽  
John T.M. Kennis ◽  
Anjali Pandit
Keyword(s):  
Physcomitrella Patens ◽  
Light Stress ◽  
Plant Stress ◽  
Ph Sensor ◽  
Structural Response ◽  
Molecular Response ◽  
Response Mechanism ◽  
Hydrophobic Membrane ◽  
Structural Mechanism ◽  
Ph Response

ABSTRACTThe membrane protein Photosystem II subunit S (PsbS) is a pH sensor that plays an essential role in signaling light stress in plants to prevent photo oxidation and generation of detrimental reactive species. PsbS detects thylakoid lumen acidification in excess light conditions via two glutamates facing the lumen, however, its molecular mechanism for activation has remained elusive. We performed an infrared and 2-dimensional infrared spectroscopic analysis of wild type Physcomitrella patens PsbS and of mutants in which the active glutamates have been replaced: E71Q, E176Q (the equivalent of E69Q and E173Q in spinach PsbS) and the double mutant E71Q/E176Q. We discovered that E71 exerts allosteric control of PsbS dimerization, while E176 is essential for the secondary structural response to low pH. Based on our results, we propose a molecular pH response mechanism that involves re-positioning of the amphipathic short helix facing the lumen, whereby it moves from the aqueous phase into the hydrophobic membrane phase upon lowering the pH. This structural mechanism may be a shared motif of protein molecular switches of the light-harvesting family and its elucidation could open new routes for crops engineering to improve photosynthetic production of biomass.

Electronic Structure and Solvation of Copper and Silver Ions:  A Theoretical Picture of a Model Aqueous Redox Reaction

2004 ◽  
Vol 126 (12) ◽  
pp. 3928-3938 ◽  
Author(s):  
Jochen Blumberger ◽  
Leonardo Bernasconi ◽  
Ivano Tavernelli ◽  
Rodolphe Vuilleumier ◽  
Michiel Sprik
Keyword(s):  
Electronic Structure ◽  
Redox Reaction ◽  
Silver Ions

scholarly journals An unknown component of a selective and mild oxidant: structure and oxidative ability of a double salt-type complex having κ1O-coordinated permanganate anions and three- and four-fold coordinated silver cations

RSC Advances ◽  
2019 ◽  
Vol 9 (49) ◽  
pp. 28387-28398 ◽  
Author(s):  
Gréta Bettina Kovács ◽  
Nóra V. May ◽  
Petra Alexandra Bombicz ◽  
Szilvia Klébert ◽  
Péter Németh ◽  
...  
Keyword(s):  
Low Temperature ◽  
Redox Reaction ◽  
Solid Phase ◽  
Silver Ions ◽  
Double Salt ◽  
Pyridine Ligands ◽  
Type Complex ◽  
Redox Active ◽  
Unknown Component ◽  
Silver Cations

A compound having redox-active permanganate and complexed silver ions with reducing pyridine ligands is used as a mild organic and as a precursor for nanocatalyst synthesis in a low-temperature solid-phase quasi-intramolecular redox reaction.

A CO2-responsive anti-corrosion ethyl cellulose coating based on the pH-response mechanism

2021 ◽  
Vol 180 ◽  
pp. 109194
Author(s):  
Jixing Wang ◽  
Junlei Tang ◽  
Hailong Zhang ◽  
Yingying Wang ◽  
Hu Wang ◽  
...  
Keyword(s):  
Ethyl Cellulose ◽  
Response Mechanism ◽  
Ph Response

Responses of Platelets to Strains of Streptococcus sanguis: Findings in Healthy Subjects, Bernard-Soulier, Glanzmann’s, and Collagen-Unresponsive Patients

1987 ◽  
Vol 57 (02) ◽  
pp. 222-225 ◽  
Author(s):  
A H Soberay ◽  
M C Herzberg ◽  
J D Rudney ◽  
H K Nieuwenhuis ◽  
J J Sixma ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Healthy Subjects ◽  
Normal Subjects ◽  
Membrane Glycoprotein ◽  
Response Mechanism ◽  
Platelet Response ◽  
Induce Platelet Aggregation ◽  
Streptococcus Sanguis ◽  
Lag Times ◽  
Bernard Soulier Syndrome

SummaryThe ability of endocarditis and dental strains of Streptococcus sanguis to induce platelet aggregation in plasma (PRP) from normal subjects were examined and compared to responses of PRP with known platelet membrane glycoprotein (GP) and response defects. S. sanguis strains differed in their ability to induce normal PRPs to aggregate. Strains that induced PRP aggregation in more than 60% of donors were significantly faster agonists (mean lag times to onset of aggregation less than 6 min) than those strains inducing response in PRPs of fewer than 60% of donors.Platelets from patients with Bernard-Soulier syndrome aggregated in response to strains of S. sanguis. In contrast, platelets from patients with Glanzmann’s thrombasthenia and from a patient with a specific defect in response to collagen were unresponsive to S. sanguis. These observations show that GPIb and V are not essential, but GPIIb-IIIa and GPIa are important in the platelet response mechanism to S. sanguis. Indeed, the data suggests that the platelet interaction mechanisms of S. sanguis and collagen may be similar.

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