Table 2. Proportions of secondary structure for SP-C peptide mimics in deuterated phosphate and hexafluoroisopropanol buffer.
Proportions of secondary structurea for SP-C peptide mimics in 10 mM deuterated phosphate buffer (dPBS, pD 7.4) and 35% hexafluoroisopropanol (HFIP)/65% dPBS, as estimated from the ATR-FTIR spectra of the peptide amide I band.
| System | % Conformationa | |||
|---|---|---|---|---|
| α-helix | β-sheet | Loop-turn | Disordered | |
| dPBS | ||||
| SP-Cff | 7.4 | 51.9 | 24.0 | 10.6 |
| SP-Cff ion-lock 1 | 17.8 | 2.9 | 59.9 | 19.5 |
| SP-Css | 15.8 | 49.7 | 14.6 | 19.9 |
| SP-Css ion-lock 1 | 40.8 | 11.8 | 18.8 | 28.7 |
| SP-C33 UCLA | 50.0 | 14.4 | 17.2 | 18.4 |
| SP-C33 ion-lock 1 | 57.8 | 14.8 | 12.2 | 15.1 |
| 35% HFIP/dPBS | ||||
| SP-Cff | 19.3 | 53.2 | 17.8 | 9.7 |
| SP-Cff ion-lock 1 | 53.0 | 13.9 | 16.9 | 16.1 |
| SP-Css | 18.5 | 35.6 | 22.1 | 23.9 |
| SP-Css ion-lock 1 | 51.1 | 10.4 | 33.1 | 5.45 |
| SP-C33 UCLA | 52.6 | 14.1 | 18.6 | 14.7 |
| SP-C33 ion-lock 1 | 49.6 | 8.01 | 1.42 | 13.7 |