  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.
