Fig. 5.

3D structure of a small molecular weight Aβ_1–40 oligomer determined by solution NMR. (A) 2D NOESY spectrum of 77 μM Aβ_1–40 dissolved in 20 mM potassium phosphate, 50 mM NaCl, pH 7.3 containing 93% H₂O and 7% D₂O recorded at 15 °C on a 900 MHz NMR spectrometer. The selected regions show NOEs that corresponds to the sequential assignment of H_αi-N_Hi+1. (B) The aromatic region of the NOESY spectrum showing cross-peaks between F19 and F20 residues, the C-terminus and F4 residue, and the central helical region of the peptide. (C) 3D NMR structures of Aβ_1–40 calculated from NOEs and backbone dihedral angle restraints. The cartoon structure shown on the right in green shows the long-range NOEs that stabilizes the formation of the hairpin structure and the bends in the N- and C-termini (red dashed lines). Copyright © 2011 Elsevier Inc. This figure is reproduced with permission from Biochemical and Biophysical Research Communications: https://doi.org/10.1016/j.bbrc.2011.06.133. Further details can be found in the published article.⁶⁹