Figure 1.

Spectroscopic characterization of hβ₂m and ΔN6 fibrils. Negative stain electron micrographs (EM) of (a) hβ₂m and (b) ΔN6 fibrils (scale bar 100 nm) and their MAS NMR spectra of (c–e) ¹³C–¹³C and (f–h) ¹³C–¹⁵N correlations. (c–e) One-bond RFDR spectra of U–¹³C,¹⁵N-hβ₂m (blue) and U–¹³C,¹⁵N-ΔN6 (red). The cross sections of S52 are shown in (e) to illustrate the peak intensity and line width. (f–h) One-bond ZF TEDOR spectra of 1,3-hβ₂m (blue) and 1,3-ΔN6 (red). (c–e) and (f–h) were acquired at 900 and 800 MHz ¹H frequencies, respectively. Assignments in spectra are residue-specific and are based on 2D and 3D experiments.