Structural similarity between beta super(3)-peptides synthesized from beta super(3)-homo-amino acids and aspartic acid monomers

• Published in: Biopolymers 2014-07, Vol.102 (4), p.359-367
• Main Authors: Ahmed, Sahar, Sprules, Tara, Kaur, Kamaljit
• Format: Article
• Language: English
• ISSN: 0006-3525; 1097-0282
• DOI: 10.1002/bip.22510

Formation of stable secondary structures by oligomers that mimic natural peptides is a key asset for enhanced biological response. Here we show that oligomeric beta super(3)-hexapeptides synthesized from l-aspartic acid monomers ( beta super(3)-peptides 1, 5a, and 6) or homologated beta super(3)-amino acids ( beta super(3)-peptide 2), fold into similar stable 14-helical secondary structures in solution, except that the former form right-handed 14-helix and the later form left-handed 14-helix. beta super(3)-Peptides from l-Asp monomers contain an additional amide bond in the side chains that provides opportunities for more hydrogen bonding. However, based on the NMR solution structures, we found that beta super(3)-peptide from l-Asp monomers (1) and from homologated amino acids (2) form similar structures with no additional side-chain interactions. These results suggest that the beta super(3)-peptides derived from l-Asp are promising peptide-mimetics that can be readily synthesized using l-Asp monomers as well as the right-handed 14-helical conformation of these beta super(3)-peptides (such as 1 and 6) may prove beneficial in the design of mimics for right-handed alpha -helix of alpha -peptides. copyright 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 359-367, 2014.