1,973 results match your criteria hydration shell

Binary structure and dynamics of the hydrogen bonds in the hydration shells of ions.

Phys Chem Chem Phys 2021 May 5. Epub 2021 May 5.

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.

Ion-specific effects of cations (Li+, Na+, K+, Mg2+, Ca2+) and anions (F-, Cl-) on the hydrogen bond structure and dynamics of the coordination waters in the hydration shells have been studied using molecular dynamics simulations. Our simulations indicate that the hydrogen bonds between the first and second hydration shell waters show binary structural and dynamic properties. The hydrogen bond with a first shell water as the donor (HD) is strengthened, while those with a first shell water as the acceptor (HA) are weakened. Read More

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Analytical Cryo-Scanning Electron Microscopy of Hydrated Polymers and Microgels.

Acc Chem Res 2021 May 4. Epub 2021 May 4.

Stevens Institute of Technology Hoboken, New Jersey 07030, United States.

ConspectusDespite the fact that scanning electron microscopes (SEM) coupled with energy-dispersive X-ray microanalysis (EDS) has been commercially available for more than a half-century, SEM/EDS continues to develop and open new opportunities to study the morphology of advanced materials. This is particularly true in applications to hydrated soft matter. Developments in field-emission electron sources that enable low-voltage imaging of uncoated polymers, silicon-drift detectors that enable high-efficiency collection of X-rays characteristic of light elements, and cryogenic methods to effectively cryo-fix hydrated samples have opened new opportunities to apply techniques relatively well established in hard-materials applications to challenging new problems involving synthetic polymers. Read More

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Confinement effects on the solvation structure of solvated alkaline metal cations in a single-digit 1T-MoS nanochannel: A first-principles study.

J Chem Phys 2021 Apr;154(16):164706

Material Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.

Confinement plays an important role in determining ion transport in porous materials, which, in turn, may influence the performance of many energy storage and desalination devices. In this work, we combined density functional theory (DFT) with an implicit solvation model and ab initio molecular dynamics (AIMD) to investigate the effects of nanoconfinement on several solvated alkaline metal cations in a single-digit 1T-MoS nanochannel. Our DFT calculations with a solvation model indicated that cations with stronger hydration energy introduce a higher number of co-intercalated water molecules into the channel, consistent with early experimental observation obtained for MXene (2D transition metal carbide) channels. Read More

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First-Principles Simulations of CuCl in High-Temperature Water Vapor.

J Phys Chem B 2021 May 3. Epub 2021 May 3.

Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.

Experimental data suggest that the solubility of copper in high-temperature water vapor is controlled by the formation of hydrated clusters of the form CuCl(HO), where the average number of water molecules in the cluster generally increases with increasing density [Migdisov, A. A.; et al. Read More

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Synchrotron XANES and EXAFS evidences for Cr and V reduction within the oil shale ashes through mixing with natural additives and hydration process.

Heliyon 2021 Apr 14;7(4):e06769. Epub 2021 Apr 14.

Elettra - Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy.

Solid friable residues (i.e. Ash) from combusted oil shale are a major environmental issue because they are highly enriched with toxic elements following combustion. Read More

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Effect of the Hydration Shell on the Carbonyl Vibration in the Ala-Leu-Ala-Leu Peptide.

Molecules 2021 Apr 8;26(8). Epub 2021 Apr 8.

Institute for Theoretical Physics, Freie Universtiät Berlin, Arnimallee 14, 14195 Berlin, Germany.

The vibrational spectrum of the Ala-Leu-Ala-Leu peptide in solution, computed from first-principles simulations, shows a prominent band in the amide I region that is assigned to stretching of carbonyl groups. Close inspection reveals combined but slightly different contributions by the three carbonyl groups of the peptide. The shift in their exact vibrational signature is in agreement with the different probabilities of these groups to form hydrogen bonds with the solvent. Read More

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Bioactive compounds and techno-functional properties of high-fiber co-products of the cacao agro-industrial chain.

Heliyon 2021 Apr 16;7(4):e06799. Epub 2021 Apr 16.

Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100, Teramo, Italy.

The cacao shell (CS) and cacao pod husk (CPH), two of the most promising high-fiber co-products of the cacao agro-industrial chain, were evaluated to determine their potential incorporation into food products. This research determined bioactive compounds and techno-functional properties of CS and CPH, and was evaluated the enzymatic inactivation by thermal treatments in CPH. We found that CS is rich in protein, lipids, dietary fiber (48. Read More

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Key Differences of the Hydrate Shell Structures of ATP and Mg·ATP Revealed by Terahertz Time-Domain Spectroscopy and Dynamic Light Scattering.

J Phys Chem B 2021 May 22;125(17):4375-4382. Epub 2021 Apr 22.

Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.

ATP is one of the main biological molecules. Many of its biological and physicochemical properties, such as energy capacity of the phosphate bonds, significantly depend on hydration. However, the structure of the hydration shell of the ATP molecule is still a matter of discussion. Read More

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Rotational Dynamics of Water at the Phospholipid Bilayer Depending on the Head Groups Studied by Molecular Dynamics Simulations.

Langmuir 2021 May 21;37(17):5329-5338. Epub 2021 Apr 21.

Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Ibaraki, Japan.

Hydration states are a crucial factor that affect the self-assembly and properties of soft materials and biomolecules. Although previous experiments have revealed that the hydration state strongly depends on the chemical structure of lipid molecules, the mechanisms at the molecular level remain unknown. Classical and density-functional tight-binding (DFTB) molecular dynamics (MD) simulations are employed to determine the mechanisms underlying dissimilar water dynamics between lipid membranes with phosphatidylcholine (PC) and phosphatidylethanolamine (PE) head groups. Read More

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Electronic Structure and Vibrational Signatures of the Delocalized Radical in Hydrated Clusters of Copper("II") Hydroxide CuOH(HO).

J Phys Chem A 2021 May 21;125(17):3631-3645. Epub 2021 Apr 21.

Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States.

The copper hydroxide ion, CuOH, serves as the catalytic core in several recently developed water-splitting catalysts, and an understanding of its chemistry is critical to determining viable catalytic mechanisms. In spite of its importance, the electronic structure of this open-shell ion has remained ambiguous in the literature. In particular, computed values for both the thermodynamics of hydration and the vibrational signatures of the mono- and dihydrates have shown prohibitively large errors compared to values from recent experimental measurements. Read More

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Kosmotropic Electrolyte (NaCO, NaF) Perturbs the Air/Water Interface through Anion Hydration Shell without Forming a Well-Defined Electric Double Layer.

J Phys Chem B 2021 Apr 20;125(16):3977-3985. Epub 2021 Apr 20.

Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Homi Bhabha National Institute, Trombay, Trombay, Mumbai 400085, India.

The ion-driven electric double layer (EDL) and the structural transformation of interfacial water are implicated in unusual reaction kinetics at the air/water interface. By combining heterodyne-detected vibrational sum frequency generation (HD-VSFG) with differential spectroscopy involving simultaneous curve fitting (DS-SCF) analysis, we retrieve electrolyte (NaCO and NaF)-correlated OH-stretch spectra of water at the air/water interface. Vibrational mapping of the perturbed interfacial water with the hydration shell spectra (obtained by DS-SCF analysis of Raman spectra) of the corresponding anion discloses that the kosmotropic electrolytes do not form well-defined EDL at the air/water interface. Read More

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Concentration-induced wettability alteration of nanoscale NaCl solution droplets on the CSH surface.

Phys Chem Chem Phys 2021 Mar 24;23(12):7449-7461. Epub 2021 Mar 24.

Department of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China.

Due to the hydrophilic nature of concrete, moisture and corrosive ions adsorbed on its surface pose a severe challenge to the durability of concrete structures; therefore, investigating the wettability of a concrete surface is an indispensable prerequisite for designing durable and sustainable concrete. This paper utilizes molecular dynamics to simulate the concentration-induced wettability alteration of nanoscale NaCl droplets on a CSH surface, and verifies the feasibility and rationality of predicting the contact angle of a droplet on the CSH surface based on the surface tension. Results suggest that the wetting ability of droplets on the CSH surface is weakened with the increase of the NaCl mass fraction. Read More

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Water structure around a left-handed Z-DNA fragment analyzed by cryo neutron crystallography.

Nucleic Acids Res 2021 May;49(8):4782-4792

Department of Biochemistry and Center for Structural Biology, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA.

Even in high-quality X-ray crystal structures of oligonucleotides determined at a resolution of 1 Å or higher, the orientations of first-shell water molecules remain unclear. We used cryo neutron crystallography to gain insight into the H-bonding patterns of water molecules around the left-handed Z-DNA duplex [d(CGCGCG)]2. The neutron density visualized at 1. Read More

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Interaction of epoxy-based hydrogels and water: A molecular dynamics simulation study.

J Mol Graph Model 2021 Apr 5;106:107915. Epub 2021 Apr 5.

Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, Jackson, MS, 39217, USA. Electronic address:

Biomaterials play a crucial role in tissue engineering as a functional replacement, regenerative medicines, supportive scaffold for guided tissue growth, and drug delivery devices. The term biomaterial refers to metals, ceramics, and polymers account for the vast majority. In the case of polymers, hydrogels have emerged as active materials for an immense variety of applications. Read More

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The nanostructure of rod-like ascorbyl dipalmitate nanoparticles stabilized by a small amount of DSPE-PEG.

Int J Pharm 2021 Apr 20;602:120599. Epub 2021 Apr 20.

Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address:

Previously, we reported the formation of 100-200 nm disk- and tube-like nanoparticles by hydration of -ascorbyl 2,6-dipalmitate (ASC-DP) and distearoylphosphatidylethanolamine polyethylene glycol 2000 (DSPE-PEG) films prepared at an initial molar ratio of 2:1. This study investigated the feasibility of nanoparticle formation with higher ASC-DP loading. Although particle size distribution determined by dynamic light scattering showed a multimodal pattern including micro-sized particles at a molar ratio of 3:1, the mean particle size gradually decreased with a further increased molar ratio. Read More

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Targeting the ALS/FTD-associated A-DNA kink with anthracene-based metal complex causes DNA backbone straightening and groove contraction.

Nucleic Acids Res 2021 Apr 9. Epub 2021 Apr 9.

Department of Life Sciences, National Chung-Hsing University, Taichung 402, Taiwan.

The use of a small molecule compound to reduce toxic repeat RNA transcripts or their translated aberrant proteins to target repeat-expanded RNA/DNA with a G4C2 motif is a promising strategy to treat C9orf72-linked disorders. In this study, the crystal structures of DNA and RNA-DNA hybrid duplexes with the -GGGCCG- region as a G4C2 repeat motif were solved. Unusual groove widening and sharper bending of the G4C2 DNA duplex A-DNA conformation with B-form characteristics inside was observed. Read More

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Molecular dynamics study of the competitive binding of hydrogen peroxide and water molecules with DNA phosphate groups.

Eur Biophys J 2021 Apr 8. Epub 2021 Apr 8.

Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 14b, Metrolohichna Str., Kyiv, 03143, Ukraine.

The interaction of hydrogen peroxide molecules with the DNA double helix is of great interest for understanding the mechanisms of anticancer therapy utilising heavy ion beams. In the present work, a molecular dynamics study of competitive binding of hydrogen peroxide and water molecules with phosphate groups of the DNA double helix backbone was carried out. The system of DNA double helix in a water solution with hydrogen peroxide molecules and Na[Formula: see text] counterions was simulated. Read More

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Unfolding and Aggregation of Lysozyme under the Combined Action of Dithiothreitol and Guanidine Hydrochloride: Optical Studies.

Int J Mol Sci 2021 Mar 8;22(5). Epub 2021 Mar 8.

Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov St., 38, 119991 Moscow, Russia.

Using a number of optical techniques (interferometry, dynamic light scattering, and spectroscopy), denaturation of hen egg white lysozyme (HEWL) by treatment with a combination of dithiothreitol (DTT) and guanidine hydrochloride (GdnHCl) has been investigated. The denaturing solutions were selected so that protein denaturation occurred with aggregation (Tris-HCl pH = 8.0, 50 mM, DTT 30 mM) or without aggregation (Tris-HCl pH = 8. Read More

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Development and Characterization of Saturated Fatty Acid-Engineered, Silica-Coated Lipid Vesicular System for Effective Oral Delivery of Alfa-Choriogonadotropin.

AAPS PharmSciTech 2021 Mar 29;22(3):118. Epub 2021 Mar 29.

Department of Pharmacology, B.V. Patel Pharmaceutical Education and Research Development Centre, Ahmedabad, Gujarat, India.

The present study was designed to develop an efficient, safe, and patient-friendly dosage form, for oral delivery of alfa-choriogonadotropin, used in the treatment of female reproductive infertility. Silica-coated, saturated fatty acid (dipalmitoylphosphatidylcholine (DPPC))-engineered, nanolipidic vesicular (NLVs) system was developed for systemic delivery of therapeutic peptide, alfa-choriogonadotropin, through oral route. DPPC-based NLVs were formulated using the technique of thin-film hydration and were coated with silica to form a homogeneous surface silica shell. Read More

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Stiffness-tuneable nanocarriers for controlled delivery of ASC-J9 into colorectal cancer cells.

J Colloid Interface Sci 2021 Jul 18;594:513-521. Epub 2021 Mar 18.

Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK; School of Pharmacy, Changzhou University, Changzhou 213164, China. Electronic address:

Hypothesis: One of the main challenges in cancer therapy is the poor water solubility of many anticancer drugs which results in low bioavailability at the tumour sites and reduced efficacy. The currently available polymer-based anticancer drug delivery systems often suffer from low encapsulation efficiency, uncontrolled release, and lack of long-term stability. Herein, we report the development of novel stiffness-tuneable core-shell nanocarriers composed of naturally derived polymers silk fibroin (SF) and sodium alginate (SA) inside a liposomal shell for enhanced cellular uptake and controlled release of hydrophobic anticancer agent ASC-J9 (Dimethylcurcumin). Read More

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Hydration Thermodynamics of Familial Parkinson's Disease-Linked Mutants of α-Synuclein.

J Chem Inf Model 2021 Apr 22;61(4):1850-1858. Epub 2021 Mar 22.

Department of Chemistry, University of Delhi, Delhi 110007, India.

The hydration thermodynamics of different mutants of α-synuclein (α-syn) related to familial Parkinson's disease (PD) is explored using a computational approach that combines both molecular dynamics simulations in water and integral equation theory of molecular liquids. This analysis focuses on the change in conformational entropy, hydration free energy (HFE), and partial molar volume of α-syn upon mutation. The results show that A53T, A30P, E46K, and H50Q mutants aggregate more readily and display increased HFE and less negative interaction volume than the wild-type α-syn. Read More

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Revisiting the dynamics of proteins during milk powder hydration using asymmetric flow field-flow fractionation (AF4).

Curr Res Food Sci 2021 23;4:83-92. Epub 2021 Feb 23.

Department of Food Technology, Engineering and Nutrition, Lund University, Getingevägen 60, 221 00, Lund, Sweden.

The dynamics of β-casein and casein micelles in the reconstitution of skim milk were revisited in this study. β-casein migrates into casein micelles upon an increase in temperatures due to an increase in the hydrophobic effect and lower calcium-phosphate cluster solubility. This process can be reversed upon cooling. Read More

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February 2021

Optimized Magnesium Force Field Parameters for Biomolecular Simulations with Accurate Solvation, Ion-Binding, and Water-Exchange Properties.

J Chem Theory Comput 2021 Apr 15;17(4):2530-2540. Epub 2021 Mar 15.

Department of Theoretical Biophysics, Max-Planck-Institute of Biophysics, Frankfurt am Main 60438, Germany.

Magnesium ions play an essential role in many vital processes. To correctly describe their interactions in molecular dynamics simulations, an accurate parametrization is crucial. Despite the importance and considerable scientific effort, current force fields based on the commonly used 12-6 Lennard-Jones interaction potential fail to reproduce a variety of experimental solution properties. Read More

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On the vibrational free energy of hydrated proteins.

Phys Biol 2021 Mar 15;18(3):036003. Epub 2021 Mar 15.

When the hydration shell of a protein is filled with at least 0.6 gram of water per gram of protein, a significant anti-correlation between the vibrational free energy and the potential energy of energy-minimized conformers is observed. This means that low potential energy, well-hydrated, protein conformers tend to be more rigid than high-energy ones. Read More

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Per|Mut: Spatially Resolved Hydration Entropies from Atomistic Simulations.

J Chem Theory Comput 2021 Apr 12;17(4):2090-2098. Epub 2021 Mar 12.

Department of Theoretical and Computational Biophysics, Max-Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.

The hydrophobic effect is essential for many biophysical phenomena and processes. It is governed by a fine-tuned balance between enthalpy and entropy contributions from the hydration shell. Whereas enthalpies can in principle be calculated from an atomistic simulation trajectory, calculating solvation entropies by sampling the extremely large configuration space is challenging and often impossible. Read More

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Conformation-induced vibrational spectral dynamics of hydrogen peroxide and vicinal water molecules.

Phys Chem Chem Phys 2021 Mar 12;23(11):6665-6676. Epub 2021 Mar 12.

Department of Chemistry, Indian Institute of Technology Hyderabad, Sangareddy-502285, Telangana, India.

We studied the conformation-induced spectral response of water molecules due to site-specific structural alterations of solvated hydrogen peroxide (HO) employing DFT-based first principles molecular dynamics (FPMD) simulations. Wavelet transform was used to determine the time-dependent frequencies of the hydroxyls of water molecules and the O-H stretch modes of HO. Shifts in the vibrational frequency of the hydrogen-bonded hydroxyls inside the solvation shell of HO support multiple distinctive hydrogen bonding environments. Read More

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Development of an albumin decorated lipid-polymer hybrid nanoparticle for simultaneous delivery of methotrexate and conferone to cancer cells.

Int J Pharm 2021 Apr 4;599:120421. Epub 2021 Mar 4.

Drug Applied Research Center, Tabriz University of Medical Science, Tabriz, Iran.

Aiming to simultaneous target of methotrexate (MTX), as folate antagonist, and conferone (CON) in various cancer cells, the newly lipid/polymer hybrid nanoparticle containing an albumin targeted succinylchitosan shell and lipoid bilayer core composed of hydrogenated soy phosphatidylcholine and cholesterol was synthesized. The covalently conjugating albumin to the external surface of chitosan was accomplished using N-(3-Dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride and N- hydroxyl succinimide as an activating carboxylic group, and nanoliposomes were fabricated via thin film hydration-sonication method. The molecular structure of MTX@CON-targeted lipid/polymer hybrid nanoparticle (MTX@CON-TLPN) were characterized using FTIR spectroscopy, H NMR, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS). Read More

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Molecular insights on poly(-isopropylacrylamide) coil-to-globule transition induced by pressure.

Phys Chem Chem Phys 2021 Mar;23(10):5984-5991

CNR-ISC and Department of Physics, Sapienza University of Rome, Piazzale A. Moro 2, 00185, Rome, Italy.

By using extensive all-atom molecular dynamics simulations of an atactic linear polymer chain, we provide microscopic insights into poly(N-isopropylacrylamide) (PNIPAM) coil-to-globule transition addressing the roles played by both temperature and pressure. We detect a coil-to-globule transition up to large pressures, showing a reentrant behavior of the critical temperature with increasing pressure in agreement with experimental observations. Furthermore, again confirming the experimental findings, we report the existence at high pressures of a new kind of globular state. Read More

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Measurement of Protein-Protein Interactions through Microscale Thermophoresis (MST).

Bio Protoc 2020 Apr 5;10(7):e3574. Epub 2020 Apr 5.

Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020 - UMR1277 - Canther - Cancer Heterogeneity, Plasticity and Resistance to Therapies, F-59000 Lille, France.

The binding interactions of PD-1 and PD-L1 have been studied by surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) over the past few years, but these investigations resulted in controversy regarding the values of the dissociation constant (K) ( Freeman , 2000 ). MST is a powerful new method for the quantitative analysis of protein-protein interactions (PPIs) with low sample consumption. The technique is based on the movement of molecules along microscopic temperature gradients, and it detects changes in their hydration shell, charge or size. Read More

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Hyaluronan orders water molecules in its nanoscale extended hydration shells.

Sci Adv 2021 Mar 3;7(10). Epub 2021 Mar 3.

Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.

Hyaluronan (HA) is an anionic, highly hydrated bio-polyelectrolyte found in the extracellular environment, like the synovial fluid between joints. We explore the extended hydration shell structure of HA in water using femtosecond elastic second-harmonic scattering (fs-ESHS). HA enhances orientational water-water correlations. Read More

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