Table 2.
Relative shares of populations (%) found for selected residues in wild-type Met-enkephalin (Gly2, Gly3, and Phe4) and for the α-tetrasubstituted α-amino acids included in the G2, G3, and F4 mutants.a
| αD | εD | γD | δD | βDL | δL | γL | εL | αL | |
|---|---|---|---|---|---|---|---|---|---|
| Gly2 | 25.1 | 8.9 | 3.1 | 0.5 | 5.0 | 1.0 | 10.1 | 34.0 | 12.3 |
| Gly3 | 29.2 | 7.3 | 30.3 | 3.6 | 7.0 | 1.9 | 5.7 | 7.3 | 7.7 |
| Phe4 | 0.0 | 0.0 | 0.0 | 19.1 | 18.4 | 3.5 | 2.9 | 21.7 | 34.4 |
| Aib2 (G2) | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Aib3 (G3) | 29.5 | 4.4 | 66.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| (2R,3R)c3diPhe4 (F4) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 13.1 | 4.7 | 82.2 |
a
The nine types of backbone conformation defined in ref. 14 have been considered.