The structure and properties of water films in contact with metal surfaces are crucial to understand the chemical electrochemical processes involved energy-related technologies. nature thin on Pd, Pt, Ru has been investigated by first-principles molecular dynamics assess how chemistry at water–metal surface is responsible for diversity behavior layers closer metal. characteristics liquid water: radial distribution functions, coordination, fragment speciation appear only unconfined a minimum...

Self-assembly in aqueous solution has been investigated for two Fmoc [Fmoc = N-(fluorenyl)-9-methoxycarbonyl] tetrapeptides comprising the RGDS cell adhesion motif from fibronectin or scrambled sequence GRDS. The hydrophobic unit confers amphiphilicity on molecules, and introduces aromatic stacking interactions. Circular dichroism FTIR spectroscopy show that self-assembly of both peptides at low concentration is dominated by interactions among units, although Fmoc-GRDS shows β-sheet...

Hydroxyapatite (HAp) particles with very different surface charges and compositions (i.e. Ca/P CO32-/PO43- ratios) have been obtained by varying the experimental conditions used during chemical precipitation process. The DNA adsorption capacity protection imparted against attack of nucleases HAp proved to depend on charge while buffering is affected composition. On basis both crystallinity, predominant planes at surfaces identified. Atomistic molecular dynamics simulations constructed these...

Encapsulation of DNA into hydroxyapatite (HAp) has been investigated using a rational approach that involves computer simulation and experimental techniques. The temporal evolution the radial distribution functions derived from atomistic molecular dynamics simulations Ca(2+), PO4(3-) OH(-)-containing aqueous solutions in presence absence B-DNA used to conclude backbone double helix acts as template for HAp growth. More specifically, results reveal formation calcium phosphate clusters at...

Abstract Polyether polyols are used widely in the plastic and coating industries form of polyurethanes. The polymerization epoxides can be catalyzed by double metal cyanides (DMCs), Zn 3 [Co(CN) 6 ] 2 . These catalysts were first reported 1960s General Tire Inc. provide products with excellent technical features, which better than those that result from traditional alkaline as side reactions alleviated. However, DMC‐catalyzed is not free drawbacks high‐molecular‐weight (1–3 wt %) propylene...

Different aspects of biominerals formed by apatite and DNA have been investigated using computer modeling tools. Firstly, the structure stability in which molecules are embedded into hydroxyapatite fluoroapatite nanopores examined combining different molecular mechanics methods. After this, early processes nucleation at a template dynamics simulations. Results indicate that duplexes adopting B double helix can be encapsulated inside without undergoing significant distortions inter-strand...

Abstract Although the content of Mg 2+ in hard tissues is very low (typically ≤1.5 wt %), its incorporation into synthetic hydroxyapatite (HAp) particles and role mineral’s properties are still subject intensive debate. A combined experimental–computational approach used to answer many open questions. ‐enriched HAp prepared using different approaches considering concentrations reaction medium. The composition, morphology structure resulting investigated X‐ray photoelectron spectroscopy,...

The manifold applications of ionene‐based materials such as hydrogels in daily life, biomedical sciences, and industrial processes are a consequence their unique physical chemical properties, which governed by judicious balance between multiple non‐covalent interactions. However, one the most critical aspects identified for broader use different polyelectrolytes is need raising gelation efficiency. This work focuses on surfactant‐free ionene polymers 1 − 3 containing DABCO N , N′ ‐( x...

The selective production of ethanol has been achieved by fixing carbon from CO₂ and CH₄. reaction, which is based on the electro-reduction CO₂, catalysed polarized hydroxyapatite occurs under mild reaction conditions.

The helical peptide Cys-Ala-Lys-(Glu-Ala-Ala-Ala-Lys)(2)-Ala-NH-(CH(2))(2)-SH has been organized forming a self-assembled monolayer on gold (0.602 peptides per nm(2)), its conductance behavior under stretching conditions being studied using scanning tunnelling microscopy and current sensing atomic force microscopy. conformation of the found to play fundamental role in conductance. Moreover, variation upon molecular indicates that can be significantly elongated before drops zero, critical...

The self-assembly of a peptide based on sequence from the amyloid β but incorporating non-natural amino acid β-2-thienylalanine (2-Thi) has been investigated in aqueous and methanol solutions. AAKLVFF was used as design motif, replacing phenylalanine residues (F) with 2-Thi units to yield (2-Thi)(2-Thi)VLKAA. are expected confer interesting electronic properties due charge delocalization π-stacking. is shown form β-sheet-rich fibrils twisted morphology, both water solutions at sufficiently...

Theoretical simulations in the field of heterogeneous catalysis started about two decades ago when main goal was to understand activation small molecules on infinite surfaces. The improvements accuracy and large availability computers with increasing power have raised quality calculations, reliability results prompted interest their predictions. Such changes also allowed study nanoparticles by combined investigation different facets or taking into account complete structures. As for...

Pre-assembled aggregates made of Fmoc-conjugated RGDS and GRDS peptides, where Fmoc refers to fluorenylmethoxycarbonyl, have been investigated using atomistic molecular dynamics simulations. The structural characteristics twelve different models involving two sheets packed with the Fmoc-aligned or charged side groups oriented face-to-face, each one containing seven explicit peptide molecules arranged in parallel antiparallel, evaluated for Fmoc-tetrapeptide. Structural criteria used select...

The adsorption of different phosphates and a triphosphonate onto hydroxyapatite has been highlighted combining experiments theoretical calculations.

The adsorption of the first water layer on metals combines several structural motifs like pentagons, hexagons, and heptagons interconnected variably leading to a myriad patterns. Although theoretical methods are now able discriminate ground states, there is need find simple ways account for relative stability different patterns surface. Taking already reported structures bilayers as training sets we have decomposed energy each their fundamental components: water-water water-metal...

Abstract In spite of the clinical importance hydroxyapatite (HAp), mechanism that controls its dissolution in acidic environments remains unclear. Knowledge such a process is highly desirable to provide better understanding different pathologies, as for example osteoporosis, and HAp potential vehicle gene delivery replace damaged DNA. this work, acid conditions nanoparticles encapsulating double‐stranded DNA has been investigated at atomistic level using computer simulations. For purpose,...

The intrinsic conformational preferences of indoline-2-carboxylic acid (Inc) and its α-methylated derivative (αMeInc) have been investigated using quantum mechanical calculations. Specifically, the behavior their N-acetyl-N'-methylamide derivatives, Ac-L-Inc-NHMe Ac-L-αMeInc-NHMe, has explored at B3LYP/6-31+G(d,p) level. Such amino acids are analogues proline (α-methyl)proline, respectively, bearing a benzene ring fused to C(γ)-C(δ) bond five-membered pyrrolidine ring. additional aromatic...

Peptides and proteins find an ever-increasing number of applications in the biomedical materials engineering fields. The use non-proteinogenic amino acids endowed with diverse physicochemical structural features opens possibility to design peptides novel properties functions. Moreover, residues are particularly useful control three-dimensional arrangement peptidic chains, which is a crucial issue for most applications. However, information regarding such acids—also called non-coded,...

Abstract Recently, we reported a database (Noncoded Amino acids Database; http://recerca.upc.edu/imem/index.htm ) that was built to compile information about the intrinsic conformational preferences of nonproteinogenic residues determined by quantum mechanical calculations, as well bibliographic their synthesis, physical and spectroscopic characterization, experimentally established propensities, applications (Revilla‐López et al ., J Phys Chem B 2010;114:7413–7422). The initially contained...

The intrinsic conformational properties of the N-acetyl-N′-methylamide derivatives d-Cα-ethylglycine (Abu), d-Cα-methyl-Cα-ethylglycine (Iva), and Cα,α-diethylglycine (Deg) have been investigated using quantum mechanical calculations in gas phase chloroform, dichloromethane aqueous solutions. Although large number flexible dihedral angles results many minimum energy conformations, only a few them are energetically representative because repulsive interactions between ethyl groups backbone...

Recently a new non-coded amino acid was designed as replacement for Arg, to protect the tumor-homing pentapeptide CREKA (Cys-Arg-Glu-Lys-Ala) from proteases. This constrained Arg analog, denoted c5Arg, engineered also promote stability of bioactive conformation. The conformational profile analog obtained by replacing c5Arg has been extensively investigated in this work. Two molecular dynamics simulations-based strategies have employed: modified simulated annealing and replica exchange....

In this work we elucidate the conformational preferences of two amyloid-forming peptides, Arginine-Vasopressin and Neuromedin-K, new biomacromolecular conjugates obtained by linking peptides to a polyester (poly(R-lactic acid)) chain. The properties hybrid have been assessed through molecular dynamics simulations compared those their individual components. Our results suggest that free unconjugated tend adopt backbone arrangements which resemble β-hairpin shape, conformation has reported...

The conformational, electrical, and optical intrinsic properties of l-phenylazophenylalanine (l-PAP), a nonproteinogenic photoresponsive amino acid used to modulate the binding affinity activity peptides proteins, have been systematically investigated using quantum mechanical calculations, with special emphasis being put on trans-to-cis isomerization azobenzene side group. Analyses conformational maps minimum-energy conformations, which were obtained density functional theory calculations at...