title: Two state behavior in a solvable model of beta-hairpin folding.
abstract: Understanding the mechanism of protein secondary structure formation is an essential part of the protein-folding puzzle. Here we describe a simple model for the formation of a beta hairpin, motivated by the fact that folding of a beta hairpin captures much of the basic physics of protein folding. The modeled hairpin is composed of two interacting Gaussian chains with one pairwise (two-body) and two many-body interactions. We show that these many-body interactions, arising from side chain packing effects, are responsible for producing an "all-or-none" folding transition. We also estimate the (single exponential) folding/unfolding rate via calculating the thermodynamic weight of the "critical" droplet/bubble.
authors.affiliation: Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0319, USA.
authors.forename: C
authors.initials: C
authors.lastname: Guo
authors.forename: H
authors.initials: H
authors.lastname: Levine
authors.forename: D A
authors.initials: DA
authors.lastname: Kessler
mesh_terms: D007700:Kinetics; D008962:Models, Theoretical; D016011:Normal Distribution; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins