Figure 2.

³J_HNHα couplings measured in the Aβ peptides. (A) Small expanded region of the ¹⁵N–¹H TROSY spectrum recorded at a ¹H frequency of 800 MHz for the Aβ^1–42 peptide showing the well-resolved doublets of cross-peaks arising from the J coupling between the ¹H^N and ¹H^α protons. (B) ³J_HNHα coupling values measured for the Aβ^1–40 (red) and Aβ^1–42 (black) peptides at 277 K. (C) Plot of ³J_HNHα measured for Aβ^1–40 (red) and Aβ^1–42 (black) against residue-specific random coil values, derived from α-synuclein.⁵⁵