scholarly journals UNDERSTANDING STRUCTURAL PREFERENCES IN KETONE-PHENOL DISPERSION BALANCES

2020 ◽  
Author(s):  
C. Zimmermann ◽  
Martin Suhm
Keyword(s):  
Structural Preferences

Local Structural Preferences of Calpastatin, the Intrinsically Unstructured Protein Inhibitor of Calpain†‡§

Biochemistry ◽  
2008 ◽  
Vol 47 (26) ◽  
pp. 6936-6945 ◽  
Author(s):  
Robert Kiss ◽  
Dénes Kovács ◽  
Péter Tompa ◽  
András Perczel
Keyword(s):  
Protein Inhibitor ◽  
Intrinsically Unstructured Protein ◽  
Structural Preferences ◽  
Unstructured Protein

Structural preferences for the double bond position in some unsaturated 3,3-diphenylpyrrolidines

1970 ◽  
Vol 48 (23) ◽  
pp. 3742-3745 ◽  
Author(s):  
M. M. A. Hassan ◽  
A. F. Casy
Keyword(s):  
Double Bond ◽  
Methyl Iodide ◽  
Quaternary Salt ◽  
Double Bond Position ◽  
Magnesium Bromide ◽  
Free Base ◽  
Spectroscopic Evidence ◽  
Structural Preferences ◽  
Ethyl Magnesium Bromide ◽  
Sole Product

The reaction between 3,3-diphenyl-3-cyano-1-methylpropyl isocyanate and ethyl magnesium bromide leads to 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline rather than the isomeric 2-ethylidenepyrrolidine. The protonated N-methyl analogue (identical with a major metabolite of methadone) retains the 1-pyrroline structure, but the free base is a cis-trans mixture of the corresponding 2-ethylidenepyrrolidines; the cis Me/Ph isomer preponderates and is the sole product (obtained as a quaternary salt) when the mixture is treated with methyl iodide. 5-Methyl-2-methylene-3,3-diphenylpyrrolidine, a lower homologue of the methadone metabolite, isomerizes to a 1-pyrroline derivative when protonated or methylated. All structural conclusions are based on i.r. and p.m.r. spectroscopic evidence.

scholarly journals Adsorption of Amino Acids on Graphene: Assessment of Current Force Fields

2019 ◽  
Author(s):  
Siva Dasetty ◽  
John K. Barrows ◽  
Sapna Sarupria
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Force Field ◽  
Force Fields ◽  
Principal Component ◽  
Free Energies ◽  
Adsorbed State ◽  
Free Energy Of Adsorption ◽  
Density Based Clustering ◽  
Structural Preferences

<div> <div> <div> <p>We compare the free energies of adsorption (∆Aads) and the structural preferences of amino acids obtained using the force fields — Amberff99SB-ILDN/TIP3P, CHARMM36/modified-TIP3P, OPLS-AA/M/TIP3P, and Amber03w/TIP4P/2005. The amino acid–graphene interactions are favorable irrespective of the force field. While the magnitudes of ∆Aads differ between the force fields, the trends in the free energy of adsorption with amino acids are similar across the studied force fields. ∆Aads positively correlates with amino acid–graphene and negatively correlates with graphene–water interaction energies. Using a combination of principal component analysis and density-based clustering technique, we grouped the structures observed in the graphene adsorbed state. The resulting population of clusters, and the conformation in each cluster indicate that the structures of the amino acid in the graphene adsorbed state vary across force fields. The differences in the conformations of amino acids are more severe in the graphene adsorbed state compared to the bulk state for all the force fields. Our findings suggest that while the thermodynamics of adsorption of proteins and peptides would be described consistently across different force fields, the structural preferences of peptides and proteins on graphene will be force field dependent. </p> </div> </div> </div>

scholarly journals Folding initiation sites and protein folding.

1999 ◽  
Vol 46 (3) ◽  
pp. 487-508 ◽  
Author(s):  
M Dadlez
Keyword(s):  
Protein Folding ◽  
Protein Fragments ◽  
Denatured State ◽  
Local Structures ◽  
Rate Limiting Step ◽  
Structural Preferences ◽  
Low Levels ◽  
Rate Limiting ◽  
Transition State Barrier

The paper discusses the role of local structural preferences of protein segments in the folding of proteins. First a short overview of the local, secondary structures detected in peptides, protein fragments, denatured proteins and early folding intermediates is given. Next the discussion of their role in protein folding is presented based on recent literature and data obtained in our laboratory. In conclusion it is pointed out that, during folding, local structures populated at low levels in denatured state may facilitate the crossing of the folding transition state barrier, and consequently accelerate the rate limiting step in folding. However, the data show that this effect does not follow simple rules.

Structural preferences of ν4-dienecyclopentadienyl complexes: molecular mechanics, molecular orbital and crystallographic studies

1998 ◽  
Vol 275-276 ◽  
pp. 263-273 ◽  
Author(s):  
Vitor Félix ◽  
Maria José Calhorda ◽  
Michael G.B. Drew ◽  
Isabel S. Gonçalves ◽  
Carlos C. Romão
Keyword(s):  
Molecular Mechanics ◽  
Molecular Orbital ◽  
Structural Preferences

scholarly journals The distinct structural preferences of tau protein repeat domains

2018 ◽  
Vol 54 (45) ◽  
pp. 5700-5703 ◽  
Author(s):  
Xuhua Li ◽  
Xuewei Dong ◽  
Guanghong Wei ◽  
Martin Margittai ◽  
Ruth Nussinov ◽  
...  
Keyword(s):  
Tau Protein ◽  
Structural Motifs ◽  
Structural Preferences

Among the four bi-repeat protofilaments, only R3–R4 can maintain the C-shaped structure that can be stabilized by heparins, while R1–R2 tends to be linear in shape, and these two structural motifs appear in the most stable K18 protofilament.

Sign in / Sign up

Export Citation Format

Share Document