Evaluation of the iterative simulated annealing technique in conformational search of peptides

Characterization of the subset of low energy minima of a peptide is hampered by the multiple minima problem associated to the roughness of its potential energy surface. The iterative simulated annealing procedure was recently proposed as an effective procedure to overcome these difficulties. In the present work results of a thorough exploration of the conformational space of the peptide Ac-Cys-Val-Tic-Met performed by means of the simulated annealing procedure is compared to the results of a random search. Profile differences in the two sets of low energy conformations obtained are analyzed. The results are also discussed in terms of the rotational isomeric model and its usefulness in assessing the degree of completeness of the conformational search.