passages.id: split_8_test_2816_passage
passages.type: progene_text
passages.text: The conformational study on cyclic Ac-Cys-Pro-Xaa-Cys-NHMe ( Ac - CPXC - NHMe ; X = Ala , Val , Leu , Aib , Gly , His , Phe , Tyr , Asn and Ser ) peptides has been carried out using the Empirical Conformational Energy Program for Peptides , version 3 ( ECEPP / 3 ) force field and the hydration shell model in the unhydrated and hydrated states .