  A generalized-ensemble technique, multicanonical sampling, is used to study
the folding of a 34-residue human parathyroid hormone fragment. An all-atom
model of the peptide is employed and the protein-solvent interactions are
approximated by an implicit solvent. Our results demonstrate that
generalized-ensemble simulations are well suited to sample low-energy
structures of such large polypeptides. Configurations with a root-mean-square
deviation (rmsd) to the crystal structure of less than one \AA are found.
Finally, we discuss limitations of our implicit solvent model.
