Thermodynamics of alpha- and beta-structure formation in proteins.
An atomic protein model with a minimalistic potential is developed and then tested on an alpha-helix and a beta-hairpin, using exactly the same parameters for both peptides. We find that melting curves for these sequences to a good approximation can be described by a simple two-state model, with parameters that are in reasonable quantitative agreement with experimental data. Despite the apparent two-state character of the melting curves, the energy distributions are found to lack a clear bimodal shape, which is discussed in some detail. We also perform a Monte Carlo-based kinetic study and find, in accord with experimental data, that the alpha-helix forms faster than the beta-hairpin.
Irbäck
Anders
A
Complex Systems Division, Department of Theoretical Physics, Lund University, Lund, Sweden. anders@thep.lu.se
Samuelsson
Björn
B
Sjunnesson
Fredrik
F
Wallin
Stefan
S
D006860:Hydrogen Bonding; D007700:Kinetics; D015233:Models, Statistical; D009010:Monte Carlo Method; D010455:Peptides / Q000737:chemistry; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
D010455:Peptides; D011506:Proteins