Consequences of Mg2+ binding on the geometry and stability of RNA base pairs

2018 ◽  
Vol 20 (34) ◽  
pp. 21934-21948 ◽  
Author(s):  
Antarip Halder ◽  
Rohit Roy ◽  
Dhananjay Bhattacharyya ◽  
Abhijit Mitra
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Base Pairs

Quantum chemical calculations reveal the role of magnesium in stabilizing the geometries of intrinsically unstable RNA base pairs.

scholarly journals Role of redox-inactive metals in controlling the redox potential of heterometallic manganese–oxido clusters

2021 ◽  
Author(s):  
Keisuke Saito ◽  
Minesato Nakagawa ◽  
Manoj Mandal ◽  
Hiroshi Ishikita
Keyword(s):  
Photosystem Ii ◽  
Redox Potential ◽  
Quantum Chemical Calculations ◽  
Catalytic Reaction ◽  
Quantum Chemical ◽  
Ionic Radius ◽  
Redox Potentials ◽  
Oxygen Evolving ◽  
Highest Occupied Molecular Orbitals

AbstractPhotosystem II (PSII) contains Ca2+, which is essential to the oxygen-evolving activity of the catalytic Mn4CaO5 complex. Replacement of Ca2+ with other redox-inactive metals results in a loss/decrease of oxygen-evolving activity. To investigate the role of Ca2+ in this catalytic reaction, we investigate artificial Mn3[M]O2 clusters redox-inactive metals  [M] ([M]  = Mg2+, Ca2+, Zn2+, Sr2+, and Y3+), which were synthesized by Tsui et al. (Nat Chem 5:293, 2013). The experimentally measured redox potentials (Em) of these clusters are best described by the energy of their highest occupied molecular orbitals. Quantum chemical calculations showed that the valence of metals predominantly affects Em(MnIII/IV), whereas the ionic radius of metals affects Em(MnIII/IV) only slightly.

scholarly journals The verticillenes. Pivotal intermediates in the biosynthesis of the taxanes and the phomactins

2019 ◽  
Vol 36 (1) ◽  
pp. 108-121 ◽  
Author(s):  
Matthew J. Palframan ◽  
Gerald Pattenden
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical

Recent enzymatic studies, quantum chemical calculations and biomimetic conversions consolidate the role of verticillenes in the biosynthesis of taxanes and phomactins.

scholarly journals Understanding thio-effects in simple phosphoryl systems: role of solvent effects and nucleophile charge

2015 ◽  
Vol 13 (19) ◽  
pp. 5391-5398 ◽  
Author(s):  
Alexandra T. P. Carvalho ◽  
AnnMarie C. O'Donoghue ◽  
David R. W. Hodgson ◽  
Shina C. L. Kamerlin
Keyword(s):  
Quantum Chemical Calculations ◽  
Solvent Effects ◽  
Quantum Chemical ◽  
Hydrolysis Of ◽  
Role Of Solvent

Detailed quantum chemical calculations provide insight on the origin of large differences in experimental thio-effects for the hydrolysis of (thio)phosphodichloridates by water and hydroxide nucleophiles.

scholarly journals Structure and separation quality of various N- and O-donor ligands from quantum-chemical calculations

Nukleonika ◽  
2015 ◽  
Vol 60 (4) ◽  
pp. 847-851 ◽  
Author(s):  
Michael Trumm ◽  
Bernd Schimmelpfennig ◽  
Andreas Geist
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Donor Ligands ◽  
Field Development ◽  
Force Field Development ◽  
The Density Functional Theory ◽  
Complexation Reactions

Abstract Although BTP (2,6-di(1,2,4-triazin-3-yl)pyridine) has been proven to be a highly effective N-donor ligand for the selective An(III)/Ln(III) separation, the origin of its selectivity is still under discussion. We present in this paper quantum-chemical calculations at the density functional theory (DFT) and MP2 level which highlight the role of the aquo ions in the separation process. Furthermore these data will be the reference for future force-field development to investigate the differences in An(III) complexation reactions compared to their Ln(III) counterparts.

IMPORTANCE OF CHARGE TRANSFER EXCITATIONS IN DNA ELECTRON SPECTRUM: A ZINDO SEMIEMPIRICAL QUANTUM-CHEMICAL STUDY

2004 ◽  
Vol 18 (16) ◽  
pp. 825-831 ◽  
Author(s):  
E. B. STARIKOV
Keyword(s):  
Charge Transfer ◽  
Quantum Chemical ◽  
Spectral Band ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Molecular Orbitals ◽  
Base Pairs ◽  
Purine Base ◽  
Dna Conformations

Electron spectra of DNA model compounds, adenosine-thymidine and guanosine-cytidine nucleoside base pairs, as well as the relevant homogeneous stacked base pair steps in A-DNA and B-DNA conformations, were investigated using ZINDO semiempirical quantum-chemical method. This work confirms that, in DNA with intact Watson–Crick hydrogen bonding and base stacking, the highest occupied molecular orbitals (HOMO) are residing on purine base residues, whereas the lowest unoccupied molecular orbitals (LUMO) — on pyrimidine base residues. In general, the present results are satisfactorily comparable with the available experimental data. The role of charge transfer excitations in the polymer DNA 260 nm spectral band is discussed.

The role of sulfur oxidation in controlling the electronic properties of sulfur-containing host molecules for phosphorescent organic light-emitting diodes

2017 ◽  
Vol 19 (19) ◽  
pp. 12002-12012 ◽  
Author(s):  
E. Varathan ◽  
V. Subramanian
Keyword(s):  
Electronic Properties ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Sulfur Oxidation ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Host Molecules ◽  
Organic Light ◽  
Sulfur Containing

Quantum chemical calculations have been used to quantify the effect of sulfur oxidation on the electronic properties of DBT based host molecules for PhOLEDs.

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