TABLE 3.

Order parameters P₂ and P₄ of the amide I components of the polarized spectra for four silk fibers

	Component	1	2	3	4	5
	assignment	Unordered	31-helix	β-sheet	β-turn	β-turn
N. clavipes	P2 (±0.02)	−0.13	−0.13	−0.39	−0.2	−0.15
	P4 (±0.02)	0.00	−0.03	0.19	0.02	0.00
N. edulis	P2 (±0.02)	−0.11	−0.10	−0.37	−0.22	−0.22
	P4 (±0.02)	−0.06	−0.08	0.20	0.02	0.02
S. c. ricini	P2 (±0.02)	−0.06	−0.10	−0.41	−0.15	−0.09
	P4 (±0.02)	−0.13	−0.22	0.24	0.06	0.03
B. mori	P2 (±0.02)	−0.10	−0.10	−0.45	−0.23	−0.20
	P4 (±0.02)	0.04	−0.20	0.30	0.16	0.12
Isotropic films	Riso* (±0.02)	0.26	0.27	0.20	0.18	0.18

^*The R_iso parameter values are averaged from spectral decompositions of the amide I band (not shown) of the β-sheet-rich regenerated films made from B. mori and S. c. ricini fibroins.