Molecular Motion of Spin Labeled Side Chains in α-Helices:  Analysis by Variation of Side Chain Structure†

Biochemistry ◽  
2001 ◽  
Vol 40 (13) ◽  
pp. 3828-3846 ◽  
Author(s):  
Linda Columbus ◽  
Támás Kálai ◽  
József Jekö ◽  
Kálmán Hideg ◽  
Wayne L. Hubbell
Keyword(s):  
Molecular Motion ◽  
Chain Structure ◽  
Side Chain ◽  
Side Chains

Motion of Spin-Labeled Side Chains in T4 Lysozyme:  Effect of Side Chain Structure†

Biochemistry ◽  
1999 ◽  
Vol 38 (10) ◽  
pp. 2947-2955 ◽  
Author(s):  
Hassane S. Mchaourab ◽  
Tamás Kálai ◽  
Kálmán Hideg ◽  
Wayne L. Hubbell
Keyword(s):  
Chain Structure ◽  
Side Chain ◽  
Side Chains ◽  
T4 Lysozyme

Modulating bioactivities of primary ammonium-tagged antimicrobial aliphatic polycarbonates by varying length, sequence and hydrophobic side chain structure

2019 ◽  
Vol 7 (6) ◽  
pp. 2288-2296 ◽  
Author(s):  
Kazuki Fukushima ◽  
Kohei Kishi ◽  
Keita Saito ◽  
Kazuki Takakuwa ◽  
Shunta Hakozaki ◽  
...  
Keyword(s):  
Chain Structure ◽  
Side Chain ◽  
Side Chains ◽  
Varying Length

A highly antimicrobial, biocompatible, and fast biodegradable polycarbonate has been developed by incorporating primary ammonium and monoether side chains.

High efficiency all-polymer solar cells realized by the synergistic effect between the polymer side-chain structure and solvent additive

2015 ◽  
Vol 3 (13) ◽  
pp. 7077-7085 ◽  
Author(s):  
Jianyu Yuan ◽  
Wanli Ma
Keyword(s):  
Solar Cells ◽  
Synergistic Effect ◽  
High Efficiency ◽  
Polymer Solar Cells ◽  
Chain Structure ◽  
Side Chain ◽  
Side Chains ◽  
Solvent Additive

The number of conjugated side chains on the donor polymer can greatly affect the performance of all-polymer solar cells.

Side chain structure affects the molecular packing and photovoltaic performance of oligothiophene-based solution-processable small molecules

RSC Advances ◽  
2015 ◽  
Vol 5 (83) ◽  
pp. 67718-67726 ◽  
Author(s):  
Shang-Che Lan ◽  
Chiao-Kai Chang ◽  
Yueh-Hsin Lu ◽  
Shu-Wei Lin ◽  
Alex K.-Y. Jen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Intermolecular Interactions ◽  
Photovoltaic Performance ◽  
Thiobarbituric Acid ◽  
Chain Structure ◽  
Central Core ◽  
Side Chain ◽  
Side Chains ◽  
Alkyl Side Chains ◽  
Chain Lengths

Small molecules with alkyl side chains of different lengths were prepared with 2,2′-bithiophene, terthiophene and thiobarbituric acid as the central core, spacer and end-cap. Uniform, shorter chain lengths gave stronger intermolecular interactions, favoring crystallization.

Influence of side chains on the self-alignment capability of electroluminescent polyfluorenes

Soft Matter ◽  
2016 ◽  
Vol 12 (7) ◽  
pp. 1983-1988 ◽  
Author(s):  
Sunyoung Lee ◽  
Yooseong Yang ◽  
Sunchul Kwon ◽  
Youngsuk Jung
Keyword(s):  
Seed Layer ◽  
Critical Role ◽  
Chain Structure ◽  
The Self ◽  
Side Chain ◽  
Side Chains

The side chain structure plays a critical role in the orientation propagation of an aligned seed layer into the bulk of the polyfluorene film by heating into its nematic melt state.

Influence of Flexible Side-Chains on the Breathing Phase Transition of Pillared Layer MOFs: A Force Field Investigation

2020 ◽  
Author(s):  
Julian Keupp ◽  
Johannes P. Dürholt ◽  
Rochus Schmid
Keyword(s):  
First Principles ◽  
Good Accuracy ◽  
Field Investigation ◽  
Square Lattice ◽  
Side Chain ◽  
Second Step ◽  
Side Chains ◽  
Dynamics Simulations ◽  
Complex Phenomena ◽  
Closed Pore

The prototypical pillared layer MOFs, formed by a square lattice of paddle-<br>wheel units and connected by dinitrogen pillars, can undergo a breathing phase<br>transition by a “wine-rack” type motion of the square lattice. We studied this not<br>yet fully understood behavior using an accurate first principles parameterized force<br>field (MOF-FF) for larger nanocrystallites on the example of Zn 2 (bdc) 2 (dabco) [bdc:<br>benzenedicarboxylate, dabco: (1,4-diazabicyclo[2.2.2]octane)] and found clear indi-<br>cations for an interface between a closed and an open pore phase traveling through<br>the system during the phase transformation [Adv. Theory Simul. 2019, 2, 11]. In<br>conventional simulations in small supercells this mechanism is prevented by periodic<br>boundary conditions (PBC), enforcing a synchronous transformation of the entire<br>crystal. Here, we extend this investigation to pillared layer MOFs with flexible<br>side-chains, attached to the linker. Such functionalized (fu-)MOFs are experimen-<br>tally known to have different properties with the side-chains acting as fixed guest<br>molecules. First, in order to extend the parameterization for such flexible groups,<br>1a new parametrization strategy for MOF-FF had to be developed, using a multi-<br>structure force based fit method. The resulting parametrization for a library of<br>fu-MOFs is then validated with respect to a set of reference systems and shows very<br>good accuracy. In the second step, a series of fu-MOFs with increasing side-chain<br>length is studied with respect to the influence of the side-chains on the breathing<br>behavior. For small supercells in PBC a systematic trend of the closed pore volume<br>with the chain length is observed. However, for a nanocrystallite model a distinct<br>interface between a closed and an open pore phase is visible only for the short chain<br>length, whereas for longer chains the interface broadens and a nearly concerted trans-<br>formation is observed. Only by molecular dynamics simulations using accurate force<br>fields such complex phenomena can be studied on a molecular level.

scholarly journals Effects of Amino Acid Side-Chain Length and Chemical Structure on Anionic Polyglutamic and Polyaspartic Acid Cellulose-Based Polyelectrolyte Brushes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1789
Author(s):  
Dmitry Tolmachev ◽  
George Mamistvalov ◽  
Natalia Lukasheva ◽  
Sergey Larin ◽  
Mikko Karttunen
Keyword(s):  
Glutamic Acid ◽  
Chain Length ◽  
Chemical Structure ◽  
Side Chain ◽  
Side Chains ◽  
Side Chain Length ◽  
Polyelectrolyte Brushes ◽  
Grafting Density ◽  
The Difference ◽  
Cellulose Surface

We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration.

scholarly journals Unusual Structural Features in the Adduct of Dirhodium Tetraacetate with Lysozyme

2021 ◽  
Vol 22 (3) ◽  
pp. 1496
Author(s):  
Domenico Loreto ◽  
Giarita Ferraro ◽  
Antonello Merlino
Keyword(s):  
Anticancer Agents ◽  
Structural Features ◽  
Side Chain ◽  
Side Chains ◽  
Valuable Insight ◽  
Experimental Conditions ◽  
Egg White Lysozyme ◽  
Potential Applications ◽  
Model Protein ◽  
Hen Egg White

The structures of the adducts formed upon reaction of the cytotoxic paddlewheel dirhodium complex [Rh2(μ-O2CCH3)4] with the model protein hen egg white lysozyme (HEWL) under different experimental conditions are reported. Results indicate that [Rh2(μ-O2CCH3)4] extensively reacts with HEWL:it in part breaks down, at variance with what happens in reactions with other proteins. A Rh center coordinates the side chains of Arg14 and His15. Dimeric Rh–Rh units with Rh–Rh distances between 2.3 and 2.5 Å are bound to the side chains of Asp18, Asp101, Asn93, and Lys96, while a dirhodium unit with a Rh–Rh distance of 3.2–3.4 Å binds the C-terminal carboxylate and the side chain of Lys13 at the interface between two symmetry-related molecules. An additional monometallic fragment binds the side chain of Lys33. These data, which are supported by replicated structural determinations, shed light on the reactivity of dirhodium tetracarboxylates with proteins, providing useful information for the design of new Rh-containing biomaterials with an array of potential applications in the field of catalysis or of medicinal chemistry and valuable insight into the mechanism of action of these potential anticancer agents.

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