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Two-state folding over a weak free-energy barrier

Favrin, Giorgio LU ; Irbäck, Anders LU ; Samuelsson, Björn LU and Wallin, Stefan LU (2003) In Biophysical Journal 85(3). p.1457-1465
Abstract
We present a Monte Carlo study of a model protein with 54 amino acids that folds directly to its native three-helix-bundle state without forming any well-defined intermediate state. The free-energy barrier separating the native and unfolded states of this protein is found to be weak, even at the folding temperature. Nevertheless, we find that melting curves to a good approximation can be described in terms of a simple two-state system, and that the relaxation behavior is close to single exponential. The motion along individual reaction coordinates is roughly diffusive on timescales beyond the reconfiguration time for a single helix. A simple estimate based on diffusion in a square-well potential predicts the relaxation time within a factor... (More)
We present a Monte Carlo study of a model protein with 54 amino acids that folds directly to its native three-helix-bundle state without forming any well-defined intermediate state. The free-energy barrier separating the native and unfolded states of this protein is found to be weak, even at the folding temperature. Nevertheless, we find that melting curves to a good approximation can be described in terms of a simple two-state system, and that the relaxation behavior is close to single exponential. The motion along individual reaction coordinates is roughly diffusive on timescales beyond the reconfiguration time for a single helix. A simple estimate based on diffusion in a square-well potential predicts the relaxation time within a factor of two. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biophysical Journal
volume
85
issue
3
pages
1457 - 1465
publisher
Cell Press
external identifiers
  • wos:000185009900010
  • scopus:0041821616
ISSN
1542-0086
language
English
LU publication?
yes
id
60924ccc-1642-427f-ace4-07a32acfecf0 (old id 302318)
alternative location
http://www.biophysj.org/cgi/content/abstract/85/3/1457
date added to LUP
2007-09-03 07:36:34
date last changed
2018-05-29 09:37:05
@article{60924ccc-1642-427f-ace4-07a32acfecf0,
  abstract     = {We present a Monte Carlo study of a model protein with 54 amino acids that folds directly to its native three-helix-bundle state without forming any well-defined intermediate state. The free-energy barrier separating the native and unfolded states of this protein is found to be weak, even at the folding temperature. Nevertheless, we find that melting curves to a good approximation can be described in terms of a simple two-state system, and that the relaxation behavior is close to single exponential. The motion along individual reaction coordinates is roughly diffusive on timescales beyond the reconfiguration time for a single helix. A simple estimate based on diffusion in a square-well potential predicts the relaxation time within a factor of two.},
  author       = {Favrin, Giorgio and Irbäck, Anders and Samuelsson, Björn and Wallin, Stefan},
  issn         = {1542-0086},
  language     = {eng},
  number       = {3},
  pages        = {1457--1465},
  publisher    = {Cell Press},
  series       = {Biophysical Journal},
  title        = {Two-state folding over a weak free-energy barrier},
  volume       = {85},
  year         = {2003},
}