MOLECULAR-DYNAMICS AND MONTE-CARLO SIMULATIONS FAVOR THE ALPHA-HELICAL FORM FOR ALANINE-BASED PEPTIDES IN WATER

Molecular dynamics and Monte Carlo simulations of a capped undecaalani ne peptide were conducted to determine the preferred helical conformat ion in water. The results clearly favor the alpha-helical form over th e 3(10) alternative, in contrast to recent ESR findings. A molecular d ynamics simulation started at the 3(10) conformation converges rapidly to an alpha-helix, and the free energy profile calculated via Monte C arlo simulations shows the alpha-helix to be more stable by ca. 1.0 kc al.mol-1 per residue.