Table I.
Fitting of FP-Hairpin ΔSr spectra.a
| Sample/(13CO label) | β sheetb | α helixb | ||||
|---|---|---|---|---|---|---|
| Peak shift (ppm) | Linewidthc (ppm) | Fractional intensity | Peak shift (ppm) | Linewidthc (ppm) | Fractional intensity | |
| Membrane/(L7) | 173.8 | 3.0 | 0.60 | 177.3 | 4.0 | 0.35 |
| 180.6 | 2.6 | 0.05 | ||||
| Membrane+D-malt/(L7) | 174.0 | 2.4 | 0.73 | 177.1 | 3.6 | 0.22 |
| 180.0 | 1.6 | 0.05 | ||||
| Membrane/(F8) | 173.4 | 3.9 | 0.43 | 177.0 | 4.1 | 0.57 |
| Membrane+D-malt/(F8) | 173.3 | 3.0 | 0.80 | 177.5 | 3.1 | 0.20 |
| Membrane/(L12) | 174.7 | 4.1 | 0.52 | 178.7 | 4.2 | 0.48 |
| Membrane+D-malt/(L12) | 174.2 | 3.3 | 0.75 | 178.5 | 3.5 | 0.25 |
| Membrane+D-malt/(F11) | 172.6 | 3.3 | 0.76 | 176.3 | 3.9 | 0.24 |
| Membrane+D-malt/(I4) | 173.7 | 4.0 | 0.88 | 178.2 | 3.5 | 0.12 |
Spectra are displayed in fig. 3 insets and are fitted to the sum of two or three Gaussian lineshapes. The black (red) colors match the colors of the inset spectra. Fits are shown in the SI.
Conformation is assigned by similarity between the peak 13CO shift and the peak shift of the database distribution of the amino acid in a specific conformation. Database peak shifts (standard deviations) in ppm include: Leu, β strand, 175.7 (1.5); Leu, helix; 178.5 (1.3); Phe, β strand, 174.3 (1.6); Phe, helix; 177.1 (1.4); Ile, β strand, 174.9 (1.4); Ile, helix, 177.7 (1.3). Each β sheet shift of FP-Hairpin is within 1 ppm of the corresponding β sheet HFP shift where HFP residue (shift) include L7 (174.2), F8 (173.8), L12 (174.4), F11 (173.3), and I4 (174.5).
Full-width at half-maximum.