WMDF-NH₂ docked to CCK-R1.

<p>Contacts between the amino acids inWMDF-NH₂ are shown as W (purple), M (green), D (brown), and F (dark blue) and the receptor, FMRFa-R, whose transmembrane regions are labeled TM# where # is 1–7. The C-terminal F was amidated, -NH₂.