Figure 10.

¹H–¹³C CP-MAS spectra of N. clavipes dragline silk fibers. (a) Neat silk fibers in dry (upper red curve) and hydrated (lower blue curve) state. The results of Creager et al [21] were used to make the amino acid assignments. Except for the Ala C_α and Ala C_β (β-sheet) peaks, the hydrated spectra are lower in intensity. (b) Neat (red) and gold-sputtered (green) silk fibers. Inset: detail of slight intensity increase in Pro C_γ and Ala C_β (helix) peaks after gold sputtering. (c) Neat (upper red curve) and lightly I₂-doped (lower black curve) silk fibers. Inset: detail of decrease in Gly C_α and Glx C_γ (Tyr C_β) peaks after I₂ doping. (d) Neat (upper red curve) and heavily I₂-doped (lower orange curve) silk fibers. Intensity reduction in most peaks is indicated by the arrow.