Exploring H-bonding interaction to enhance proton permeability of an acid-selective membrane

2021 ◽  
pp. 119650
Author(s):  
Wanjie Song ◽  
Yubin He ◽  
Muhammad A. Shehzad ◽  
Xiaolin Ge ◽  
Liang Ge ◽  
...  
Keyword(s):  
Proton Permeability ◽  
Bonding Interaction ◽  
Selective Membrane

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

Novel palladium(II) selective membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol

2010 ◽  
Vol 75 (5) ◽  
pp. 563-575 ◽  
Author(s):  
Moslem Mohammadi ◽  
Mehdi Khodadadian ◽  
Mohammad K. Rofouei
Keyword(s):  
Limit Of Detection ◽  
Membrane Electrode ◽  
Aqueous Samples ◽  
Selective Determination ◽  
Poly Vinyl Chloride ◽  
Selective Membrane ◽  
Ph Range ◽  
Palladium Content ◽  
Methyl Benzene

A plasticized poly(vinyl chloride) membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol (L) for highly selective determination of palladium(II) (in PdCl42– form) is developed. The electrode showed a good Nernstian response (29.6 ± 0.4 mV per decade) over a wide concentration range (3.1 × 10–7 to 1.0 × 10–2 mol l–1). The limit of detection was 1.5 × 10–7 mol l–1. The electrode has a response time of about 20 s, and it can be used for at least 2 months without observing any considerable deviation from Nernstian response. The proposed electrode could be used in the pH range of 2.5–5.5. The practical utility of the electrode has been demonstrated by its use for the estimation of palladium content in aqueous samples.

Non-Covalent Bonding Interaction between Primaquine as Guest and 2-(Hydroxypropyl)-β-Cyclodextrin as Host

2020 ◽  
pp. 1-18
Author(s):  
Moorthiraman Murugan ◽  
Rajaram Rajamohan ◽  
Arumugam Anitha ◽  
Madi Fatiha
Keyword(s):  
Covalent Bonding ◽  
Bonding Interaction

scholarly journals Proton permeability of sarcoplasmic reticulum vesicles.

1980 ◽  
Vol 255 (14) ◽  
pp. 6814-6819 ◽  
Author(s):  
G. Meissner ◽  
R.C. Young
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Proton Permeability

scholarly journals Ion-to-electron capacitance of single-walled carbon nanotube layers before and after ion-selective membrane deposition

2021 ◽  
Vol 188 (5) ◽  
Author(s):  
Elena Zdrachek ◽  
Eric Bakker
Keyword(s):  
Carbon Nanotube ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Essential Step ◽  
Before And After ◽  
Selective Membrane ◽  
High Potential Stability ◽  
Potential Stability

AbstractThe capacitance of the ion-to-electron transducer layer helps to maintain a high potential stability of solid-contact ion-selective electrodes (SC-ISEs), and its estimation is therefore an essential step of SC-ISE characterization. The established chronopotentiometric protocol used to evaluate the capacitance of the single-walled carbon nanotube transducer layer was revised in order to obtain more reliable and better reproducible values and also to allow capacitance to be measured before membrane deposition for electrode manufacturing quality control purposes. The capacitance values measured with the revised method increased linearly with the number of deposited carbon nanotube–based transducer layers and were also found to correlate linearly before and after ion-selective membrane deposition, with correlation slopes close to 1 for nitrate-selective electrodes, to 0.7 and to 0.5 for potassium- and calcium-selective electrodes. Graphical abstract

Sign in / Sign up

Export Citation Format

Share Document