Two-state protein-like folding of a homopolymer chain

Details Two-state protein-like folding of a homopolymer chain Two-state protein-like folding of a homopolymer chain

2010-05-27

arxiv.org/abs/1005.5099v1

Physics

Condensed Matter

Soft Condensed Matter

10 pages, 5 figures, prepared for Physics Procedia: 23rd Annual Workshop on Recent Developments in Computer Simulation Studies

Scientific paper

Many small proteins fold via a first-order "all-or-none" transition directly from an expanded coil to a compact native state. Here we study an analogous direct freezing transition from an expanded coil to a compact crystallite for a simple flexible homopolymer. Wang-Landau sampling is used to construct the 1D density of states for square-well chains of length 128. Analysis within both the micro-canonical and canonical ensembles shows that, for a chain with sufficiently short-range interactions, the usual polymer collapse transition is preempted by a direct freezing or "folding" transition. A 2D free-energy landscape, built via subsequent multi-canonical sampling, reveals a dominant folding pathway over a single free-energy barrier. This barrier separates a high entropy ensemble of unfolded states from a low entropy set of crystallite states and the transition proceeds via the formation of a transition-state folding nucleus. Despite the non-unique homopolymer ground state, the thermodynamics of this direct freezing transition are identical to the thermodynamics of two-state protein folding. The model chain satisfies the van't Hoff calorimetric criterion for two-state folding and an Arrhenius analysis of the folding/unfolding free energy barrier yields a Chevron plot characteristic of small proteins.

Affiliated with

Also associated with

No associations

Rating

Two-state protein-like folding of a homopolymer chain does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Two-state protein-like folding of a homopolymer chain, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-state protein-like folding of a homopolymer chain will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-192640