Selective complexation of alkaline earth metal ions with nanotubular cyclopeptides: DFT theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2305-2317 ◽  
Author(s):  
Fereshte Shahangi ◽  
Alireza Najafi Chermahini ◽  
Hossein Farrokhpour ◽  
Abbas Teimouri
Keyword(s):  
Density Functional Theory ◽  
Metal Ions ◽  
Cyclic Peptides ◽  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Functional Theory ◽  
Alkaline Earth Metal Ions

The interaction of alkaline earth metal cations including Be2+, Mg2+, Ca2+, Sr2+ and Ba2+ with cyclic peptides containing 3 or 4 (S) alanine molecules (CyAla3 and CyAla4) was investigated by density functional theory (DFT-CAM-B3LYP and DFT-B3LYP).

Structure, stability and intramolecular interaction of M(N5)2(M = Mg, Ca, Sr and Ba) : a theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21823-21830 ◽  
Author(s):  
Xueli Zhang ◽  
Junqing Yang ◽  
Ming Lu ◽  
Xuedong Gong
Keyword(s):  
Energetic Materials ◽  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Intramolecular Interaction ◽  
Earth Metal ◽  
Structure Stability ◽  
Alkaline Earth Metal ◽  
Functional Theory ◽  
The Density Functional Theory

The potential energetic materials, alkaline earth metal complexes of the pentazole anion (M(N5)2, M = Mg2+, Ca2+, Sr2+and Ba2+), were studied using the density functional theory.

Activation of Cellulose with Alkaline Earth Metals

2021 ◽  
Author(s):  
Gregory Facas ◽  
Vineet Maliekkal ◽  
Matthew Neurock ◽  
Paul Dauenhauer
Keyword(s):  
Density Functional ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Density Functional Theory Calculations ◽  
Alkaline Earth Metal ◽  
Magnesium Ions ◽  
Functional Theory ◽  
Naturally Occurring ◽  
Alkaline Earth Metal Ions ◽  
And Control

Alkaline earth metal ions accelerate the breaking of cellulose bonds and control the distribution of products in the pyrolysis of lignocellulose to biofuels and chemicals. Here, the activation of cellulose via magnesium ions was measured over a range of temperatures from 370 to 430 ⁰C for 20 to 2000 milliseconds and compared with activation of cellulose via calcium, another naturally-occurring alkaline earth metal in lignocellulose materials. The experimental approach of pulse heated analysis of solid/surface reactions (PHASR) showed that magnesium significantly catalyzes cellulose activation with a second order rate dependence on the catalyst concentration. An experimental barrier of 45.6 ± 2.1 kcal mol-1 and a pre-factor of 1.18 x 1016 (mmol Mg2+ / g CD)-2 * s-1 was obtained for the activation of α-cyclodextrin (CD), a cellulose surrogate, for catalyst concentrations of 0.1 to 0.5 mmol Mg+2 per gram of CD. First principles density functional theory calculations showed that magnesium ions play a dual role in catalyzing the reaction by breaking the hydrogen bonds with hydroxymethyl groups and destabilizing the reacting cellulose chain, thus making it more active. The calculated barrier of 47 kcal mol-1 is in agreement with the experimentally measured barriers and similar to that for calcium ion catalysts (~50 kcal mol-1).

Computational Study: Noncovalent Interaction of Cys-Ala Peptide with Alkaline Earth Metal Ions and its Conformation Changes

2021 ◽  
Vol 874 ◽  
pp. 128-135
Author(s):  
Mutiara Anisa Tresnoningtias ◽  
Andre Sasongko Nurwarrohman ◽  
Ihyar Kurnia ◽  
Christian Rinaldy ◽  
Asy’ari Mukhammad ◽  
...  
Keyword(s):  
Metal Ions ◽  
Density Functional ◽  
Alkaline Earth ◽  
Computational Study ◽  
Earth Metal ◽  
Basis Set ◽  
Alkaline Earth Metal ◽  
Interaction Energies ◽  
Water Solvent ◽  
Alkaline Earth Metal Ions

The study of the intermolecular interactions is important to explain the phenomenon occurred on the human body. One of the most important processes that can be studied is the interaction of the peptide with metal ions. In this study, a computational approach was harnessed to predict the interaction and the changes in peptide’s conformation between Cys-Ala peptide which is one of the important amino acids in e-cadherin with some of alkaline earth metal ions. Cys-Ala peptide (Ac-CA-NH2) was used as a molecular model in this calculation. All the molecular structure involved in the interaction was optimized by density functional theory DFT/M06-2X, and basis set 6-31G** to obtain minimum energy, the interaction energies, and the changes in its conformation. The results showed that the interaction energy of Ac-CA-NH2 with alkaline earth metal ions from top to bottom based on the Periodic table is getting higher in a row. The interaction energies of Ac-CA-NH2 with Be2+, Mg2+ and Ca2+ ions are -2.393kcal, -17.489 kcal, and -25.938 kcal respectively. These energies were obtained from the interaction of the peptide with ions in a water solvent. The changes in the peptide's bond length and dihedral angle indicate a conformational change in the Cys-Ala peptide, but it still maintains the trans conformation in its peptide bonds. The results and evaluations of this study may be used for further research considerations and may be applied to enzymes or other peptides that have the Cys-Ala residue.

A first-principles study on alkaline earth metal atom substituted monolayer boron nitride (BN)

2017 ◽  
Vol 5 (32) ◽  
pp. 8112-8127 ◽  
Author(s):  
Rafique Muhammad ◽  
Yong Shuai ◽  
He-Ping Tan
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Boron Nitride ◽  
Dft Calculations ◽  
First Principles ◽  
Density Functional ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Functional Theory

This paper presents first-principles density functional theory (DFT) calculations for the structural, electronic, magnetic and optical properties of monolayer boron nitride (BN) doped with different alkaline earth metal (AEM) atoms.

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