Design, Synthesis, and Conformational Analysis of Secondary Structure Elements

Methods Alternating D,L-peptides are able to assume specific conformations including, among other, various kinds of single and double stranded ?-helix structures, predicted also on theoretical ground, and ?-extended chains that can aggregate through parallel or antiparallel H bonds and yield pleated (or rippled) sheet. The stability of each structure depends on the influence of various structural factors, such as the length of the peptide chain, the nature of the lateral substituents, and the end groups, the solvent and the specific pattern of configuration (LDL or DLD) which may modify the conformational properties of D, L-alternating peptides. Both helix and extended structures are stabilized by a complex network of molecular interactions (principally H-bonds and hydrophobic interaction) [1, 2]. Here we have used these models to study the conformational behaviour in solution of several synthetic oligomers of modest length (6-20 residues). Influence of pattern of configuration (LDL or DLD) The influence of asymmetric carbon atom of the side chains on the conformational properties of polypeptides.