  We study the free energy landscape of the small peptide Met-enkephalin. Our
data were obtained from a generalized-ensemble Monte Carlo simulation taking
the interactions among all atoms into account. We show that the free energy
landscape resembles that of a funnel, indicating that this peptide is a good
folder. Our work demonstrates that the energy landscape picture and folding
concept, developed in the context of simplified protein models, can also be
used to describe the folding in more realistic models.
