Electrostatic Effects on the Stability of Peptide Radicals

2018 ◽  
Vol 122 (38) ◽  
pp. 8880-8890 ◽  
Author(s):  
Harish Jangra ◽  
Hendrik Zipse
Keyword(s):  
Electrostatic Effects ◽  
The Stability ◽  
Peptide Radicals

The search for formal electrostatic effects on molecular conformation and crystal packing: crystal structure of 2,2′′-disubstituted (HversusPPh2) 1,1′-(1,2-phenylene)bis(3-methyl-1H-imidazol-3-ium) bis(trifluoromethanesulfonate)

2016 ◽  
Vol 72 (3) ◽  
pp. 198-202
Author(s):  
Carine Duhayon ◽  
Yves Canac ◽  
Laurent Dubrulle ◽  
Carine Maaliki ◽  
Remi Chauvin
Keyword(s):  
Crystal Structure ◽  
Electrostatic Interactions ◽  
Molecular Conformation ◽  
Crystal Packing ◽  
Relative Orientation ◽  
Electron Delocalization ◽  
Electrostatic Effects ◽  
Conformational Freedom ◽  
The Stability ◽  
Bond Character

Electrostatic interactions between localized integral charges make the stability and structure of highly charged small and rigid organics intriguing. Can σ/π-electron delocalization compensate reduced conformational freedom by lowering the repulsion between identical charges? The crystal structure of the title salt, C14H16N42+·2CF3SO3−, (2), is described and compared with that of the 2,2′′-bis(diphenylphosphanyl) derivative, (4). The conformations of the dications and their interactions with neighbouring trifluoromethanesulfonate anions are first analyzed from the standpoint of formal electrostatic effects. Neither cation exhibits any geometrical strain induced by the intrinsic repulsion between the positive charges. In contrast, the relative orientation of the imidazolium rings [i.e. antifor (2) andsynfor (4)] is controlled by different configurations of the interactions with the closest trifluoromethanesulfonate anions. The long-range arrangement is also found to be specific: beyond the formal electrostatic packing, C—H...O and C—H...F contacts have no definite `hydrogen-bond' character but allow the delineation of layers, which are either pleated or flat in the packing of (2) or (4), respectively.

Electrostatic effects control the stability and iron release kinetics of ovotransferrin

2014 ◽  
Vol 19 (6) ◽  
pp. 1009-1024 ◽  
Author(s):  
Sandeep Kumar ◽  
Deepak Sharma ◽  
Rajesh Kumar ◽  
Rajesh Kumar
Keyword(s):  
Release Kinetics ◽  
Iron Release ◽  
Electrostatic Effects ◽  
The Stability ◽  
Kinetics Of

Electrostatic Effects on the Stability of Discoidal High-Density Lipoproteins†

Biochemistry ◽  
2005 ◽  
Vol 44 (30) ◽  
pp. 10218-10226 ◽  
Author(s):  
Sangeeta Benjwal ◽  
Shobini Jayaraman ◽  
Olga Gursky
Keyword(s):  
High Density ◽  
High Density Lipoproteins ◽  
Electrostatic Effects ◽  
The Stability

The Stability of C α Peptide Radicals: Why Glycyl Radical Enzymes?

2011 ◽  
Vol 17 (13) ◽  
pp. 3781-3789 ◽  
Author(s):  
Johnny Hioe ◽  
Gökcen Savasci ◽  
Harald Brand ◽  
Hendrik Zipse
Keyword(s):  
Glycyl Radical ◽  
The Stability ◽  
Peptide Radicals ◽  
Radical Enzymes

Free surface instability in electrohydrodynamics

1968 ◽  
Vol 64 (2) ◽  
pp. 527-534 ◽  
Author(s):  
D. H. Michael
Keyword(s):  
Free Surface ◽  
Electric Field ◽  
Radial Electric Field ◽  
Surface Charges ◽  
Electrostatic Effects ◽  
The Subject ◽  
Free Surface Instability ◽  
The Stability ◽  
Wave Problems ◽  
Effect Of Surface

The study of electrostatic effects on the motion of fluids goes back to the work of Rayleigh (l) who discussed the effect of surface charges on the vibration of spherical drops, and Bassett (2) who studied the effect of a radial electric field on the stability of a jet. The subject has recently been taken up again by Melcher (3) and Crowley (4), and the author became interested in the subject through the monograph of the former author in which a wide variety of wave problems are described.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

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