Fig. 7.

The 2D proton-detected ¹³C/¹H HSQC NMR spectrum of moderately ¹³C-enriched (10-15%) Black Widow dragline silk. The delays τ and τ′ were set equal to 150 μs, the MAS frequency was 60 kHz, the recycle delay was 5 s, the sweep width in the indirect dimension was 30 kHz, no proton decoupling was applied and 80 scans were acquired for each of the 128 t₁ points.