The backbone amide bonds in two series of tetrapeptide-based CCK-A rec
eptor agonists were systematically replaced with the methylene amino i
sostere. Potent and selective pseudopeptides were identified that will
facilitate our understanding of how these peptides interact with the
CCK receptor and their structural correlations with other CCK ligands.
This information will aid in the eventual development of peptidomimet
ics.