Bioactive Peptides Based on Open-Chain -Turn Mimetics

Bioactive Peptides Based on Open-Chain y -Turn Mimetics 

In light of the importance of the / -turn motif in peptide and protein recognition, and the design and synthesis of bioactive small molecules, / -turn mimetics has attracted considerable attention. Seebach and coworkers have shown recently that low molecular weight open-chain / - and y-peptides designed to promote turn formation can be used as templates for mimicking the a-peptide hormone somatostatin. 

On this basis (see Fig. 2.41), various y9-di- and tetra-peptides incorporating [f-HLys-yS -HTrp (e.g. 160 [99], 161 [254]) or y9 -HTrp-y9 -HTrp, a-Trp-y9 -Lys [254] sequences as well as y -dipeptides with a Trp side-chain in the y -position for the first residue and a Lys side chain in the y -position for the second residue (e.g. 

163 and 164 [204]) have been synthesized and evaluated for binding to human somatostatin receptors (Fig. 2.42). 

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