TABLE 1.
Structural and dynamical parameters determined in the PVA and in the trehalose matrix
| Matrix | Model | Fe-Nɛ2(1) (Å) | Fe-Nɛ2(2) (Å) | Fe-Oɛ1 (Å) | Fe-Oɛ2 (Å) | Δα (°) | σ2 (10−3 Å2) | ΔE0 (eV) | R (%) |  |
|---|---|---|---|---|---|---|---|---|---|---|
| 4 His | 2.14 (2) | 1.94 (3) | 2.42 (5) | 6 (2) | 6 (2) | 7 (2) | 34 (10) | 46 (14) | ||
| PVA | 2 + 2 His | 2.18 (4) | 1.99 (3) | 2.09 (3) | 2.43 (6) | 3 (2) | 4 (1) | 5 (3) | 18 (6) | 13 (4) |
| 3 + 1 His | 2.16 (3) | 1.97 (6) | 2.02 (3) | 2.43 (5) | 5 (2) | 5 (2) | 6 (2) | 25 (8) | 33 (11) | |
| 4 His | 2.16 (2) | 1.98 (3) | 2.42 (9) | 5 (3) | 6 (1) | 7 (2) | 29 (9) | 22 (7) | ||
| Trehalose | 2 + 2 His | 2.17 (5) | 2.04 (2) | 2.15 (7) | 2.41 (7) | 2 (2) | 5 (1) | 5 (2) | 21 (6) | 12 (4) |
| 3 + 1 His | 2.12 (2) | 1.98 (4) | 2.19 (5) | 2.41 (6) | 1 (2) | 5 (1) | 6 (2) | 23 (7) | 21 (7) |
The bending angle of the Glu residue is indicated by Δα, and the first-shell Debye-Waller factor by σ2. The Fe-Oɛ2 distance is calculated by inserting the best-fitting values of the Fe-Oɛ1 distance and α + Δα into Eq. 1. For each RC-matrix system, the fit was performed according to three structural models, characterized by a different grouping of the four His residues (see text for details). We report in parentheses the 1σ error on the least significant digit calculated by the fitting program. The 1σ error for the Fe-Oɛ2 distance was evaluated by considering the propagation of the errors associated with the best-fitting parameters inserted into Eq. 1.