Figure 2. Molecular illustrations of SP-B mimic peptide N-terminal – C-terminal amphipathic helix hairpin structures.

(A) Mini-B peptide with the longer N-terminal amphipathic alpha helix in red highlight ribbon and the shorter C-terminal amphipathic helix as red ribbon with cysteine disulfide linkages shown in yellow (Protein Data Bank accession code: PDB 2DWF). Bend and disordered structures shown as green tube. (B) Super Mini-B peptide with longer amphipathic helix in red ribbon connected to N-terminal insertion sequence represented as a blue tubular structure. Bend connecting N-terminal helix to C-terminal alpha helix shown as a green tube with cysteine disulfide linkages in yellow (ModelArchive accession code: ma-abz44). (C) B-YL construct with N-terminal insertion sequence as blue tube structure with N-terminal helix in red connected by bend domain shown as green tubular structure to the C-terminal amphipathic helix in red ribbon. The tyrosine side chain pi-pi interactions that stabilize the helical hairpin structure are illustrated in yellow highlight (ModelArcive accession code: ma-vilb7).