Fig. 8.

Slices extracted from (a – c) 2D refocused INEPT-HETCOR NMR spectrum and (d – f) 2D proton-detected ¹³C/¹H HSQC NMR spectrum of moderately ¹³C-enriched (10-15%) Black Widow dragline silk. All experimental and processing parameters were identical for the two experiments. The delays τ and τ′ were set equal to 150 μs, the MAS frequency was 60 kHz, the recycle delay was 2 s, the sweep width in the indirect dimension was 30 kHz and 80 scans were acquired for each of the 96 t₁ points. Exponential multiplication (lb = 50 Hz) was used for apodization in both dimensions. The slices were extracted at the corresponding ¹H and ¹³C chemical shifts for the two experiments, respectively. The signal to noise ratio (S/N) is shown for each slice