Acyclic oligopeptides

As the distance of separation of the terminal functional groups increases, the sensitivity of the conformation towards solution parameters decreases. Attractions between side-chains become more dominant in determining conformations of longer peptides these interacting side-chains do not necessarily have to be close together if they are polar, but may be bridged by water molecules. 

---

The design and construction of acyclic oligopeptide molecules, which form supramoleeular (3-sheetstructures. 

Upon completion of the biosynthesis, the oligopeptide must be released by the enzyme complex. This transformation is achieved by a TE domain located after the PCP domain in the final module of the NRPS. After initial transfer of the terminal carboxyl function from the thiol of the PCP to a serine residue in the TE, the ester is either hydrolyzed to yield an acyclic product or engaged by a nucleophile on the peptide chain to afford a cyclic product. In the case of cyclic products, the exact nature of the cycle (i.e., ring size) is governed by features in the TE. 

---