Table 3. Comparison of secondary structure for recombinant vs. native AcSp1 dope and fibres.
|
Dopea |
Fibrea |
||||
|---|---|---|---|---|---|
| W2 | N. clavipes | W2 | A. aurantia | N. clavipes | |
| α-helix (%) | 40 | 49 | 32 | 33 | 24 |
| β-sheet (%) | 0 | 0 | 28 | 27 | 30 |
aProportions in W2 in dope are based upon the ensemble of W1 structures determined in NMR buffer, given that W2 in NMR buffer is fibre-forming-competent. All other proportions are based upon amide I band orientation-insensitive Raman spectral decomposition. The uncertainty on the values is ±3% based on the reproducibility of the experiments and curve-fitting procedure11. N. clavipes results were previously published7 and are provided for comparison. Decomposition of W2 and A. aurantia fibres is detailed in Supplementary Fig. S7.