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Thermodynamic Studies of Macromolecular Models

Sommelius, Ola LU (1997)
Abstract
The thermodynamic properties of single chain polyelectrolyte and protein models are studied using Monte Carlo simulations and (for the polyelectrolyte models) variational calculations and high- and low-temperature expansions. A variational method is used for minimizing Lennard-Jones energies and for estimating end-to-end distances for a rigid Coulomb chain at finite temperatures. A polyelectrolyte chain is viewed as Gaussian chain augmented with a Coulomb or screened Coulomb (Debye-Huckel) interaction between all pairs of monomers. Variational calculations are also used together with Monte Carlo simulations to study the behavior of a titrating polyelectrolyte. Furthermore a method for mapping the original polymer to a smaller one by... (More)
The thermodynamic properties of single chain polyelectrolyte and protein models are studied using Monte Carlo simulations and (for the polyelectrolyte models) variational calculations and high- and low-temperature expansions. A variational method is used for minimizing Lennard-Jones energies and for estimating end-to-end distances for a rigid Coulomb chain at finite temperatures. A polyelectrolyte chain is viewed as Gaussian chain augmented with a Coulomb or screened Coulomb (Debye-Huckel) interaction between all pairs of monomers. Variational calculations are also used together with Monte Carlo simulations to study the behavior of a titrating polyelectrolyte. Furthermore a method for mapping the original polymer to a smaller one by introducing a corrective nearest-neighbor interaction is presented. The underlying assumptions for this approach is examined using high- and low-temperature expansions. The effect of the screening length on the stiffness, defined by the persistence length, of a screened Coulomb chain is studied. Moreover a three dimensional off-lattice model for protein folding is presented. The model has two types of residues, hydrophobic and hydrophilic respectively, that interact via a sequence dependent Lennard-Jones potential. The influence of sequence independent local interactions is studied as well as the folding properties and the formation of the native state. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Marinari, Enzo, Italy
organization
publishing date
type
Thesis
publication status
published
subject
keywords
classical mechanics, Mathematical and general theoretical physics, termodynamik, klassisk mekanik, Matematisk och allmän teoretisk fysik, statistisk fysik, gravitation, kvantmekanik, relativitet, quantum mechanics, relativity, statistical physics, thermodynamics, Fysicumarkivet A:1997:Sommelius
pages
15 pages
publisher
Department of Theoretical Physics, Lund University
defense location
Auditorium, Dept. of Theoretical Physics
defense date
1997-05-29 10:15
external identifiers
  • other:ISRN: LUNFD6/(NFTF-1033)/1-15/(1997)
ISBN
91-628-2546-1
language
English
LU publication?
yes
id
0f7a418a-ca15-41b6-9ba6-3c4b63ef2728 (old id 29367)
date added to LUP
2007-06-13 13:22:51
date last changed
2016-09-19 08:45:11
@phdthesis{0f7a418a-ca15-41b6-9ba6-3c4b63ef2728,
  abstract     = {The thermodynamic properties of single chain polyelectrolyte and protein models are studied using Monte Carlo simulations and (for the polyelectrolyte models) variational calculations and high- and low-temperature expansions. A variational method is used for minimizing Lennard-Jones energies and for estimating end-to-end distances for a rigid Coulomb chain at finite temperatures. A polyelectrolyte chain is viewed as Gaussian chain augmented with a Coulomb or screened Coulomb (Debye-Huckel) interaction between all pairs of monomers. Variational calculations are also used together with Monte Carlo simulations to study the behavior of a titrating polyelectrolyte. Furthermore a method for mapping the original polymer to a smaller one by introducing a corrective nearest-neighbor interaction is presented. The underlying assumptions for this approach is examined using high- and low-temperature expansions. The effect of the screening length on the stiffness, defined by the persistence length, of a screened Coulomb chain is studied. Moreover a three dimensional off-lattice model for protein folding is presented. The model has two types of residues, hydrophobic and hydrophilic respectively, that interact via a sequence dependent Lennard-Jones potential. The influence of sequence independent local interactions is studied as well as the folding properties and the formation of the native state.},
  author       = {Sommelius, Ola},
  isbn         = {91-628-2546-1},
  keyword      = {classical mechanics,Mathematical and general theoretical physics,termodynamik,klassisk mekanik,Matematisk och allmän teoretisk fysik,statistisk fysik,gravitation,kvantmekanik,relativitet,quantum mechanics,relativity,statistical physics,thermodynamics,Fysicumarkivet A:1997:Sommelius},
  language     = {eng},
  pages        = {15},
  publisher    = {Department of Theoretical Physics, Lund University},
  school       = {Lund University},
  title        = {Thermodynamic Studies of Macromolecular Models},
  year         = {1997},
}