the analysis of the 27al and 35cl quadrupole coupling parameters of aluminum methyl chloride dimers were carried out on the basis of the density functional theory (dft). the available experimental values of quarupole coupling constants were compared with their calculated ones. in this investigation, the correlations were made between calculated 27al and 35cl nuclear quadrupole coupling constant...

to improve drug selectivity toward target cells, one interesting approach for drug delivery is to use polymer nanoparticles. a two-layered oniom becke3- lyp: uff calculation was carried out to study the structural and thermodynamic properties of the interaction between acetamide derivatives and the pca-peg-pca copolymers. the interaction enthalpies and the gibbs free energies between acetamide ...

The energy storage and the molecular rearrangements due to the primary photochemical event in rhodopsin are investigated by using quantum mechanics/molecular mechanics hybrid methods in conjunction with high-resolution structural data of bovine visual rhodopsin. The analysis of the reactant and product molecular structures reveals the energy storage mechanism as determined by the detailed molec...

BACKGROUND Chitosan and Alginate were used as biopolymers to prepare membranes for protein adsorption. The network requires a cross-linker able to form bridges between polymeric chains. Viscopearl-mini(®) (VM) was used as a support to synthesize them. Six different types of membranes were prepared using the main compounds of the matrix: VM, Chitosan of low and medium molecular weight, and Algin...

Glycogen synthase kinase 3β (GSK3β) is a serine/threonine kinase that requires two cofactor Mg(2+) ions for catalysis in regulating many important cellular signals. Experimentally, Li(+) is a competitive inhibitor of GSK3β relative to Mg(2+), while this mechanism is not experienced with other group I metal ions. Herein, we use native Mg(2)(2+)-Mg(1)(2+) GSK3β and its Mg(2)(2+)-M(1)(+) (M = Li, ...

In this article, we theoretically analyze the Diels-Alder cycloaddition between cyclopentadiene and C60 for which experimental results on energy barriers and reaction energies are known. The comparison of the results obtained with the two-layered ONIOM approach using different partitions for the high- and low-level layers with those obtained employing the B3LYP/6-31G(d) method for the entire sy...

We have studied the convergence properties of embedded and constrained cluster models of proton transfer in zeolites. We applied density functional theory to describe clusters and ONIOM to perform the embedding. We focused on converging the reaction energy and barrier of the O(1) to O(4) jump in H-Y zeolite as well as vibrational and structural aspects of this jump. We found that using successi...

The role of water molecules is increasingly gaining interest in drug design, and several studies have highlighted their paramount contributions to the specificity and the affinity of ligand binding. In this study, we employ the two-layer ONIOM-based quantum mechanics/molecular mechanics (QM/MM) calculations, molecular dynamics (MD) simulations, and molecular docking studies to investigate the e...