TABLE 7.
Key residues that alter the pKa difference between Asp-85 and Asp-212 in the presence of the protonated Schiff base (in pKa units)
Side, side chain; bb, backbone; ND = not determined.
| BR (1C3W) residue | pKa (Asp-85) = 1.5 |
pKa (Asp-212) = −2.0 |
||||
|---|---|---|---|---|---|---|
| Side | bb | Total | Side | bb | Total | |
| Met-56 | −0.4 | −0.8 | −1.2 | −0.1 | −0.3 | −0.3 |
| Tyr-57 | −0.5 | −0.3 | −0.9 | v3.2 | −0.2 | −3.4 |
| Ala-81 | 0.0 | 0.7 | 0.8 | 0.0 | 0.1 | 0.1 |
| Arg-82 | −3.9 | 0.8 | −3.1 | −6.4 | 0.1 | −6.3 |
| Asp-85 | ND | ND | ND | 6.4 | −0.4 | 6.0 |
| Trp-86 | −0.2 | −0.6 | −0.8 | v0.8 | −0.3 | −1.0 |
| Thr-89 | −2.0 | −0.9 | −2.9 | 0.1 | −0.2 | −0.1 |
| Tyr-185 | −0.3 | −0.1 | −0.4 | −3.2 | −0.1 | −3.3 |
| Glu-194 | 1.2 | −0.1 | 1.2 | 1.8 | −0.1 | 1.7 |
| Phe-208 | 0.0 | 0.2 | 0.2 | 0.0 | 1.8 | 1.8 |
| Asp-212 | 6.3 | −0.1 | 6.2 | ND | ND | ND |
| Schiff | −9.5 | 0.2 | −9.3 | −9.3 | 0.6 | −8.7 |