Structure-activity and biophysical studies of the C-terminal hexapeptide of endothelin

A series of endothelin-1 [16-21] analogs, designed to incorporate random coil and beta-turn conformations, was synthesized. Compounds were compared for their endothelin receptor binding affinity and functional activity relative to the native sequence. They were studied by NMR spectroscopy in an attempt to elucidate the bioactive conformation of the C-terminal region.