Fig. 4: NMR structures of aPP variants.
From: Stabilization of a miniprotein fold by an unpuckered proline surrogate
A Overlay of the NMR-derived dimeric structural ensemble of 7 (gray) and the reported X-ray structure of wild-type aPP (orange). B–D NMR-derived dimeric structural ensembles for ΔaPro-substituted aPP analogs 10 (green), 12 (blue), and 15 (yellow). ΔaPro residues in each structure are indicated with spheres. (E) Aligned lowest energy (state 1) monomer chains of 7, 10, 12, and 15. F Interchain Tyr7−Tyr7’ π−π interaction observed in the NMR structure (state 1) of wt aPP (7). G A shift in the Tyr7/Tyr7’ χ1 angle leads to intramolecular T-shaped π interactions with Phe20/Phe20’ in the NMR structure (state 1) of 15. H Intramolecular Gln4−Tyr27 H-bond observed in the NMR structure (state 1) of wt aPP (7). I Potential Pro2−Tyr27 CH−π interaction in the NMR structure (state 1) of ΔaPro4 aPP (10).
