Figure 7. Representations of the amphipathic helical region in β-endorphin.
(A) Human β-endorphin [12–28] represented both as an α-helical net projection (left) and as a π-helical net projection (right) [90]. The lipophilic (hydrophobic) residues are circled. (B) Human β-endorphin [12–30] represented as an axial projection of a π-helix [91].