LONG-RANGE INTERACTIONS IN THE HELICOIDAL DNA DYNAMICS

2013 ◽  
Vol 27 (24) ◽  
pp. 1350143 ◽  
Author(s):  
MIRABEAU SAHA ◽  
TIMOLEON C. KOFANÉ

In this paper, the comparison between power-law long-range interaction and Kac–Baker long-range interaction in the DNA molecule is investigated. This is done by employing an extended version of spin-like model of the DNA molecule with long-range interaction between intra-strand nucleotides and helicoidal coupling between inter-strand nucleotides when an RNA-polymerase binds to the DNA at biological temperature. Results show that LRIs have an undeniable effect on the DNA dynamics and that one is free to use either PLLRI or KBLRI to study DNA behaviors.

2012 ◽  
Vol 26 (19) ◽  
pp. 1250101 ◽  
Author(s):  
MIRABEAU SAHA ◽  
TIMOLÉON C. KOFANÉ

The effects of long-range interactions between peptides on the protein–DNA dynamics in the long-wave limit are studied. The investigation, done at the physiological temperature, is based on a coupled spin system of DNA molecule which includes the helicoidal geometry of DNA molecule and the Kac–Baker long-range interaction between the peptides of the protein molecule. By using the Holstein–Primakoff bosonic representation of the spin operators, we show that the original discrete equations for the protein–DNA interaction dynamics can be reduced to the nonlinear Schrödinger (NLS) equation of which the dispersive and the nonlinear coefficients depend among other things on the protein long-range interaction parameter and on the helicoidal coupling coefficient. Furthermore, we find that the amplitude and the width of the resulting breather solution, in the form of the bubble moving along the DNA molecule, are strongly influenced by the long-range and helicoidal interactions. This result shows a relevant length scale for real protein–DNA interaction.


1938 ◽  
Vol 34 (2) ◽  
pp. 238-252 ◽  
Author(s):  
J. S. Wang

The statistical theory of long-range interactions between adsorbed particles on a plane lattice is worked out approximately, by treating in detail the distribution of adsorbed particles among a few sites inside and on the boundary of a circular region, and regarding the distribution outside the circle as uniform and continuous with a density Kθ per unit area, where K is the number of lattice points per unit area and θ is the fraction of surface covered by adsorbed particles. The continuous distribution begins at a distance ρ from the centre of the circle, ρ being determined by the condition that the probability of occupation of a first shell site is equal to the probability θ of occupation of the central site. Using this method, general formulae for the adsorption isotherm and the heat of adsorption are obtained. Numerical applications for dipole interactions and for quadratic and hexagonal lattices are worked out in detail and the case in which the dipole moment varies with θ is discussed.


1986 ◽  
Vol 89 ◽  
Author(s):  
W. J. M. De Jonge ◽  
Twardowski A ◽  
Denissen C.J.M.

AbstractData are presented yielding evidence on the long-range character of magnetic interactions in Diluted Magnetic Semiconductors. The radial dependence of these interactions is deduced from the concentration dependence of the freezing temperature. It is shown that calculations of the thermodynamic properties, which include this long-range interaction, are in fair agreement with the experimental data.


2002 ◽  
Vol 718 ◽  
Author(s):  
Jian Yu ◽  
X. J. Meng ◽  
J.L. Sun ◽  
G.S. Wang ◽  
J.H. Chu

AbstractIn this paper, size-induced ferroelectricit yweakening, phase transformation, and anomalous lattice expansion are observed in nanocrystalline BaTiO3 (nc-BaTiO3) deriv ed b y low temperature hydrothermal methods, and they are w ellunderstood using the terms of the long-range interaction and its cooperative phenomena altered by particle size in covalen t ionic nanocrystals. In cubic nc-BaTiO3, five modes centerd at 186, 254, 308, 512 and 716 cm-1 are observed Raman active in cubic nanophase, and they are attributed to local rhombohedral distortion breaking inversion-symmetry in cubic nanophase. The254 and 308 cm-1 modes are significantly affected not only by the concentration of hydroxyl defects, but also their particular configuration. And the 806 cm-1 modes found to be closely associated with OH - absorbed on grain boundaries.


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