Figure 6.

Electrostatic surface area for the control Ac-His-DPhe-Arg-Trp-NH₂ (JRH887-9 1), Ac-His-(pI)DPhe-Arg-Trp-NH₂ (EMH4-105 3), and Ac-His-(pCl)DPhe-Arg-Trp-NH₂ (EMH4-104 12) control tetrapeptides as well as the 8 tetrapeptides (4–11) that were tested at all the polymorphic hMC4Rs and mouse MCRs examined in this study (Tables 5 and 6). The His/Arg residue at the first position is oriented at the top of the molecule, and the Arg/amino acid side chain at the third position is oriented down. The electrostatic surfaces were calculated using Maestro 9.5 (Schr̈odinger) with red (−5.0) to blue (+5.0) using the solute dielectric constant of 10 and the solvent dielectric constant of 80.