Synthesis and Helical Structures of Poly(ω-alkynamide)s Having Chiral Side Chains: Effect of Solvent on Their Screw-Sense Inversion

2014 ◽  
Vol 20 (46) ◽  
pp. 15131-15143 ◽  
Author(s):  
Yuji Suzuki ◽  
Yu Miyagi ◽  
Masashi Shiotsuki ◽  
Yoshihito Inai ◽  
Toshio Masuda ◽  
...  
Keyword(s):  
Side Chains ◽  
Helical Structures ◽  
Effect Of Solvent

Cyclic α,α-Disubstituted α-Amino Acids with Menthone in Their Side-Chains Linked through an Acetal Moiety and Helical Structures of Their Peptides

2016 ◽  
Vol 2016 (17) ◽  
pp. 2988-2998 ◽  
Author(s):  
Kaori Furukawa ◽  
Makoto Oba ◽  
George Ouma Opiyo ◽  
Mitsunobu Doi ◽  
Masakazu Tanaka
Keyword(s):  
Amino Acids ◽  
Side Chains ◽  
Helical Structures

Double versus single helical structures of oligopyridine-dicarboxamide strands. Part 2: The role of side chains

Tetrahedron ◽  
2007 ◽  
Vol 63 (27) ◽  
pp. 6322-6330 ◽  
Author(s):  
Debasish Haldar ◽  
Hua Jiang ◽  
Jean-Michel Léger ◽  
Ivan Huc
Keyword(s):  
Side Chains ◽  
Helical Structures

scholarly journals Pressure-dependent helix inversion of poly(quinoxaline-2,3-diyl)s containing chiral side chains in non-aqueous solvents

2015 ◽  
Vol 51 (56) ◽  
pp. 11182-11185 ◽  
Author(s):  
Yuuya Nagata ◽  
Ryohei Takeda ◽  
Michinori Suginome
Keyword(s):  
Side Chains ◽  
Helical Structures

Poly(quinoxaline-2,3-diyl)s with chiral (S)-2-butoxymethyl side chains dissolved in 1,2-dichloroethane experience a reversible pressure-dependent helix inversion from P- to M-helical structures between 0.1 MPa and 200 MPa.

scholarly journals Water-mediated interactions determine helix formation of peptides in open nanotubes

2020 ◽  
Author(s):  
Dylan Suvlu ◽  
D. Thirumalai ◽  
Jayendran C. Rasaiah
Keyword(s):  
Water Reservoir ◽  
Side Chains ◽  
Helical Structures ◽  
Helix Formation ◽  
The Difference ◽  
Two Phases ◽  
The Stability ◽  
Dynamics Simulations ◽  
Polypeptide Chains ◽  
Entropic Stabilization

AbstractWater-mediated interactions (WMIs) play diverse roles in molecular biology. They are particularly relevant in geometrically confined spaces such as the interior of the chaperonin, at the interface between ligands and their binding partners, and in the ribosome tunnel. Inspired in part by the geometry of the ribosome tunnel, we consider confinement effects on the stability of peptides. We describe results from replica exchange molecular dynamics simulations of a system containing a 23-alanine or 23-serine polypeptide confined to non-polar and polar nanotubes in the gas phase and when open to a water reservoir. We quantify the effect of water in determining the preferred conformational states of these polypeptides by calculating the difference in the solvation free energy for the helix and coil states in the open nanotube in the two phases. Our simulations reveal several possibilities. We find that nanoscopic confinement preferentially stabilizes the helical state of polypeptides with hydrophobic side chains, which is explained by the entropic stabilization mechanism proposed on the basis of polymer physics. Polypeptide chains with hydrophilic side chains can adopt helical structures within nanotubes, but helix formation is sensitive to the nature of the nanotube due to WMIs. We elaborate on the potential implications of our findings to the stability of peptides in the ribosome tunnel.

Studies of a Defective Measles Virus

1968 ◽  
Vol 26 ◽  
pp. 208-209
Author(s):  
R. M. McCombs ◽  
M. Benyesh-Melnick ◽  
J. P. Brunschwig
Keyword(s):  
Inclusion Bodies ◽  
Measles Virus ◽  
Giant Cells ◽  
Helical Structures ◽  
Thin Sections ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Culture Cells ◽  
Infected Cells ◽  
Eosinophilic Inclusions

Measles virus is an agent that is capable of replicating in a number of different culture cells and generally causes the formation of multinucleated giant cells. As a result of infection, virus is released from the cells into the culture fluids and reinfection can be initiated by this cell-free virus. The extracellular virus has been examined by negative staining with phosphotungstic acid and has been shown to be a rather pleomorphic particle with a diameter of about 140 mμ. However, no such virus particles have been detected in thin sections of the infected cells. Rather, the only virus-induced structures present in the giant cells are eosinophilic inclusions (intracytoplasmic or intranuclear). These inclusion bodies have been shown to contain helical structures, resembling the nucleocapsid observed in negatively stained preparations.

Effect of Solvent Quality on the Behaviour of Highly Charged Polyelectrolytes

1995 ◽  
Vol 5 (9) ◽  
pp. 1269-1275 ◽  
Author(s):  
W. Essafi ◽  
F. Lafuma ◽  
C. E. Williams
Keyword(s):  
Effect Of Solvent ◽  
Solvent Quality

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

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