Table 1.
Effect of slow ring flips on possible positions of Phe and Tyr residues
| Position | Δδ1H (ppm) | Δδ13C (ppm) | LB 1H | LB 13C | Rex13C | Ring flip | RD method |
|---|---|---|---|---|---|---|---|
| Y3δ | 0.40 | 2.11 | Yes | Yes | Yes | Slow | 1H/13C |
| Y3ε | 0.50 | 1.40 | Yes | Yes | Yes | Slow | 1H/13C |
| F30δ | 0.84 | 5.39 | Yes | Yes | Yes | Slow | 1H/13C |
| F30ε | 0.56 | 0.00 | Yes | No | No | Slow | 1H |
| Y33δ | No | No | No | Fast | |||
| Y33ε | No | No | No | Fast | |||
| Y45δ | Slow | ||||||
| Y45ε | Yes | Yes | Yes | Slow | 1H/13C | ||
| F52δ | No | No | Slow | ||||
| F52ε | 0.00 | 1.76 | No | Yes | Yes | Slow | 13C |
Δδ: chemical shift difference between individual signals of both sides of the ring, detected at − 5 °C and 200 MPa. LB: significant line broadening at lower temperatures. Rex: exchange contribution of R2 at lower temperatures. RD method: suitable relaxation dispersion method to study slow ring flips on this position