A novel approach for studies of the molecular conformations in flexible polypeptides

Abstract

proline in ‘random coil’ polypeptide chains is characteristic for the ammo acid sequence in the immediate environment of the prolyl residue, and that this equilibrium can be sensitive to the formation of energetically favored flexible molecular conformations which could otherwise in most cases not be detected by the common experimental techniques. The proposed method should be of particular interest for investigations of medium size linear poly- peptides, where the folding of the molecule is very little restricted by the covalent structure [l] . It might thus be used for studies of a variety of polypeptide hormones which have been found by other methods [2-41 to exist in flexible ‘random coil’ solution con- formations. More detailed insight into the molecular species formed by this class of compounds is of much interest because it appears that different molecular ccnformations in solution, in complexes with carrier proteins, and at the receptor site might be intimately related with the biological roles of these polypeptide hormones