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You searched for: Journal TheJournal of physical chemistry Remove constraint Journal: TheJournal of physical chemistry Publication Year 2019 Remove constraint Publication Year: 2019 Source 2019 v.123 no.8 Remove constraint Source: 2019 v.123 no.8
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1. m-s-m Cationic Gemini and Zwitterionic Surfactants–Spacer-Dependent Synergistic Interactions

Author:
McLachlan, Aleisha; Singh, Kulbir; Piggott, Emily; McAlduff, Michael; MacLennan, Shannon; Sandre, Victoria; Reid, Taryn; Marangoni, D. Gerrard
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1855-1868
ISSN:
1520-5207
Subject:
cationic surfactants; micelles; quaternary ammonium compounds; spectroscopy; synergism; zwitterions
Abstract:
... Critical micelle concentration (cmc) values were determined for the mixed zwitterionic/cationic gemini systems of N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (ZW3–12)/N,N′-bis(dimethyldodecyl)-α,ω-alkanediammonium dibromide (12-s-12) systems. The cmc values for the mixed systems were determined through conductivity measurements. The degree of nonideality of the interaction in the mixed mic ...
DOI:
10.1021/acs.jpcb.8b09771

2. Exposing the Nucleation Site in α-Helix Folding: A Joint Experimental and Simulation Study

Author:
Acharyya, Arusha; Ge, Yunhui; Wu, Haifan; DeGrado, William F.; Voelz, Vincent A.; Gai, Feng
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1797-1807
ISSN:
1520-5207
Subject:
crosslinking; hydrogen bonding; infrared spectroscopy; molecular dynamics; peptides; phase transition; protein folding; simulation models
Abstract:
... One of the fundamental events in protein folding is α-helix formation, which involves sequential development of a series of helical hydrogen bonds between the backbone C═O group of residues i and the −NH group of residues i + 4. While we now know a great deal about α-helix folding dynamics, a key question that remains to be answered is where the productive helical nucleation event occurs. Statisti ...
DOI:
10.1021/acs.jpcb.8b12220

3. The Effect of Gold Nanoparticle Concentration and Laser Fluence on the Laser-Induced Water Decomposition

Author:
Simakin, Aleksander V.; Astashev, Maxim E.; Baimler, Ilya V.; Uvarov, Oleg V.; Voronov, Valery V.; Vedunova, Maria V.; Sevost’yanov, Mikhail A.; Belosludtsev, Konstantin N.; Gudkov, Sergey V.
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1869-1880
ISSN:
1520-5207
Subject:
acoustics; ethanol; ethyl ether; hydrogen; hydrogen peroxide; irradiation; nanogold; nanoparticles; oxygen; solvents
Abstract:
... This Article covers the influence of the concentration of gold nanoparticles on laser-induced water decomposition. It was established that addition of gold nanoparticles intensifies laser-induced water decomposition by almost 2 orders of magnitude. The water decomposition rate was shown to be maximal at a nanoparticle concentration around 10¹⁰ NP/mL, whereas a decrease or increase of nanoparticle ...
DOI:
10.1021/acs.jpcb.8b11087

4. Role of Ligand Conformation on Nanoparticle–Protein Interactions

Author:
Simonelli, Federica; Rossi, Giulia; Monticelli, Luca
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1764-1769
ISSN:
1520-5207
Subject:
chemical composition; gold; human serum albumin; hydrophobicity; intravenous injection; ligands; nanogold; nanoparticles; protein corona
Abstract:
... Engineered biomedical nanoparticles (NPs) administered via intravenous routes are prone to associate to serum proteins. The protein corona can mask the NP surface functionalization and hamper the delivery of the NP to its biological target. The design of corona-free NPs relies on our understanding of the chemical-physical features of the NP surface driving the interaction with serum proteins. Here ...
DOI:
10.1021/acs.jpcb.8b11204

5. Tetrameric Charge-Zipper Assembly of the TisB Peptide in Membranes—Computer Simulation and Experiment

Author:
Schneider, Violetta; Wadhwani, Parvesh; Reichert, Johannes; Bürck, Jochen; Elstner, Marcus; Ulrich, Anne S.; Kubař, Tomáš
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1770-1779
ISSN:
1520-5207
Subject:
Escherichia coli; bacteria; biofilm; circular dichroism spectroscopy; gel electrophoresis; hydrogen bonding; molecular dynamics; pH; peptides; phospholipids
Abstract:
... TisB is a short amphiphilic α-helical peptide from Escherichia coli that induces a breakdown of the pH gradient across the inner membrane when the bacteria are under stress and require to form persister cells to turn into a biofilm. A computational–experimental approach combining all-atom and coarse-grained molecular dynamics simulation with circular dichroism spectroscopy and gel electrophoresis ...
DOI:
10.1021/acs.jpcb.8b12087

6. Hydration and Counterion Binding of an Aminomethylated Resorcin[4]arene

Author:
Moreno-Gómez, Nicolás; Vargas, Edgar F.; Buchner, Richard
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1840-1846
ISSN:
1520-5207
Subject:
aqueous solutions; aromatic hydrocarbons; chlorides; dielectric spectroscopy; hydrochloric acid; hydrogen bonding; ions
Abstract:
... Supramolecular chemistry based on host–guest complexes is a rapidly evolving research field with numerous potential applications. However, up to date investigations mainly focused on molecular recognition and self-assembly in nonpolar media where hydrogen-bond formation could be used for selective host–guest binding. Obviously, in aqueous solutions hydration will compete, hampering supramolecular ...
DOI:
10.1021/acs.jpcb.8b11900

7. Dynamics of Dicyanamide in Ionic Liquids is Dominated by Local Interactions

Author:
Hunger, Johannes; Roy, Soham; Grechko, Maksim; Bonn, Mischa
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1831-1839
ISSN:
1520-5207
Subject:
activation energy; ambient temperature; anions; anisotropy; infrared spectroscopy; ionic liquids; viscosity
Abstract:
... The dynamics of probe molecules is commonly used to investigate the structural dynamics of room-temperature ionic liquids; however, the extent to which this dynamics reflects the dynamics of the ionic liquids or is probe specific has remained debated. Here, we explore to what extent the vibrational and rotational dynamics of the dicyanamide anion, a common ionic liquid anion, correlates with the s ...
DOI:
10.1021/acs.jpcb.8b10849

8. Structural Modification of DNA Studied by Scanning Tunneling Microscopy

Author:
Terasaki, Kohei; Yokoyama, Takashi
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1780-1783
ISSN:
1520-5207
Subject:
DNA; gold; scanning tunneling microscopy; simulation models
Abstract:
... In addition to the well-known double-helix structure of deoxyribonucleic acid (DNA), theoretical simulations have predicted structural variants, such as cross and T-shaped formations. The direct visualization of individual DNA molecules by scanning probe microscopy should be able to identify these structures. In this study, we examine various structures of DNA deposited on Au(111) by using an elec ...
DOI:
10.1021/acs.jpcb.8b12100

9. UV Resonance Raman Structural Characterization of an (In)soluble Polyglutamine Peptide

Author:
Jakubek, Ryan S.; White, Stephen E.; Asher, Sanford A.
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1749-1763
ISSN:
1520-5207
Subject:
Raman spectroscopy; ambient temperature; aqueous solutions; hydrogen bonding; neurodegenerative diseases; peptides; proteins; water solubility
Abstract:
... Fibrillization of polyglutamine (polyQ) tracts in proteins is implicated in at least 10 neurodegenerative diseases. This generates great interest in the structure and the aggregation mechanism(s) of polyQ peptides. The fibrillization of polyQ is thought to result from the peptide’s insolubility in aqueous solutions; longer polyQ tracts show decreased aqueous solution solubility, which is thought t ...
DOI:
10.1021/acs.jpcb.8b10783

10. Protein Ions Generated by Native Electrospray Ionization: Comparison of Gas Phase, Solution, and Crystal Structures

Author:
Bakhtiari, Maryam; Konermann, Lars
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1784-1796
ISSN:
1520-5207
Subject:
X-radiation; crystal structure; gases; ionization; ions; lysozyme; models; molecular dynamics; protein structure; protons; solvents; spectroscopy; ubiquitin
Abstract:
... Experiments and molecular dynamics (MD) simulations in the literature indicate that gaseous proteins generated by electrospray ionization (ESI) can retain native-like structures. However, the exact properties of these ions remain to be explored. Focusing on ubiquitin and lysozyme, we examined several pertinent questions. (1) We applied solvent MD runs to test whether the X-ray structures of both p ...
DOI:
10.1021/acs.jpcb.8b12173

11. Vibrational Cooling in Oligomeric Viologens of Different Sizes and Topologies

Author:
Liu, Mengdi; Kawauchi, Takehiro; Iyoda, Tomokazu; Piotrowiak, Piotr
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1847-1854
ISSN:
1520-5207
Subject:
cooling; energy; molecular dynamics; paraquat; simulation models; solvents; spectroscopy; temperature; topology; wavelengths
Abstract:
... Vibrational cooling was investigated in a set of homologous dimers and trimers with methyl viologen repeat units (MV²⁺). The rapid, <500 fs decay of the D₁ excited state of monoreduced viologen (MV⁺•) via a conical intersection allows the preparation of a vibrationally hot D₀ ground state with a large excess energy of 1.7 eV, which is equivalent to the initial effective temperature of ∼800 K. Pump ...
DOI:
10.1021/acs.jpcb.8b12165

12. Structure and Reactivity of the Ionic Liquid 1-Allyl-3-methylimidazolium Iodide under High Pressure

Author:
Faria, Luiz F. O.; Nobrega, Marcelo M.; Falsini, Naomi; Fanetti, Samuele; Temperini, Marcia L. A.; Bini, Roberto; Ribeiro, Mauro C. C.
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1822-1830
ISSN:
1520-5207
Subject:
X-ray diffraction; ambient temperature; chemical bonding; ionic liquids; moieties; oligomerization; polymers; spectroscopy; topology
Abstract:
... Poly(ionic liquid)s are an interesting class of compounds because of their unique chemical and physical properties gathering the characteristics of ionic liquids and polymers. Pressure and temperature have been demonstrated to be alternative parameters to obtain polymers from monomeric species using only physical tools. In this work, we investigate the reaction under high pressure and room tempera ...
DOI:
10.1021/acs.jpcb.8b10669

13. N-Methylacetamide Aqueous Solutions: A Neutron Diffraction Study

Author:
Di Gioacchino, Michael; Bruni, Fabio; Ricci, Maria Antonietta
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1808-1814
ISSN:
1520-5207
Subject:
Monte Carlo method; aqueous solutions; glutathione; hydrogen bonding; neutron diffraction; proteins; tripeptides
Abstract:
... The hydration of N-methylacetamide (NMA) in solution has been determined by neutron diffraction with isotopic Hydrogen/Deuterium substitution (NDIS), augmented by Monte Carlo simulation. This study is representative of the hydration of the peptide bonds characteristic of proteins and might shed light on aggregation phenomena in intrinsically disordered proteins. It is found that NMA forms hydrogen ...
DOI:
10.1021/acs.jpcb.9b00246

14. Proton Transfer and Ionicity: An ¹⁵N NMR Study of Pyridine Base Protonation

Author:
Hasani, Mohammad; Amin, Samrat A.; Yarger, Jeffery L.; Davidowski, Stephen K.; Angell, C. Austen
Source:
TheJournal of physical chemistry 2019 v.123 no.8 pp. 1815-1821
ISSN:
1520-5207
Subject:
Bronsted acids; acidity; electrolytes; gases; ionic liquids; nitrogen; nuclear magnetic resonance spectroscopy; protonation; pyridines; stable isotopes; viscosity
Abstract:
... Protic ionic liquids (PILs) are made by proton transfer from a Brønsted acid to a base and are of interest for their solvent and electrolyte properties such as high ionic conductivity. Unfortunately, many PILs have been misnamed, because their ionic content is minimal due to an insufficient driving force for the proton transfer. Here we review this problem and introduce a new method, using ¹⁵N NMR ...
DOI:
10.1021/acs.jpcb.8b10632