Fig. 2.

Variable temperature 1D MAS ssNMR of Q44-HttEx1 fibrils. (A) 1D ¹³C CP-MAS ssNMR at 277, 270, 263 and 256 K, reflecting signals of rigid and immobilized parts of the fibrils. Dashed lines mark select peaks in different parts of HttEx1, as indicated. (B) 1D ¹³C direct excitation MAS ssNMR showing signals of both (semi)rigid and mobile residues. All data acquired at 600 MHz (¹H) and 10 kHz MAS rates. Assignments are based on (Lin et al., 2017). (C) Enlargement of Cα signals for random coil (rc) and PPII prolines. (D) ¹H NMR of water molecules at 277 K (black), 270 K (blue), 263 K (red), 256 K (green), as indicated. (E) Same data as panel D, zoomed 20X to show low intensity signals at 263 and 256 K. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)