TABLE 1.
Parameters used in the fittings of ENDOR spectra of 
in H2O and 
in D2O at 35 GHz and T = 80 K
| Direction | x | y | z |
|---|---|---|---|
| g-value (±0.0001) | 2.0065 | 2.0053 | 2.0021 |
| Hyperfine components (Ai) | Ax′ [MHz] | Ay′ [MHz] | Az′ [MHz] |
| N−H…O1 (Ala M260) | −4.54 ± 0.02 | −4.93 ± 0.02 | +8.95 ± 0.07 |
| N−D…O1 (Ala M260) | −0.70 ± 0.01 | −0.76 ± 0.01 | +1.37 ± 0.02 |
| Nδ−H…O4 (His M219) | −6.49 ± 0.03 | −6.51 ± 0.02 | +9.15 ± 0.10 |
| Nδ−D…O4 (His M219) | −0.98 ± 0.01 | −1.00 ± 0.01 | +1.36 ± 0.03 |
| Euler angles (between A and g) [deg] | φ | θ | |
| N−H…O1 (Ala M260) | −16 ± 8 | 63 ± 2 | |
| N−D…O1 (Ala M260) | −14 ± 8 | 68 ± 3 | |
| Nδ−H…O4 (His M219) | −167 ± 2 | 50 ± 2 | |
| Nδ−D…O4 (His M219) | −160 ± 6 | 54 ± 2 | |
| Quadrupolar components (2Pi) | 2Px″ [kHz] | 2Py″ [kHz] | 2Pz″ [kHz] |
| N−D…O1 (Ala M260) | −140 ± 10 | −62 ± 6 | +202 ± 6 |
| Nδ−D…O4 (His M219) | −82 ± 6 | −86 ± 8 | +168 ± 10 |
| Euler angles (between P and g) [deg] | α | β | γ |
| N−D…O1 (Ala M260) | −17 ± 10 | 47 ± 3 | 10 ± 10 |
| Nδ−D…O4 (His M219) | −175 ± 8 | 37 ± 3 | −* |
*
The nqc tensor corresponding to Nδ−D…O4 has axial symmetry, so its axes with respect to the g-tensor are determined by only two Euler angles (α and β).