Table 2.
Predicted approximate stabilization of the anionic state of the D-propionate group of heme o3 (a3) by its charge interactions (21) with R438 (R481 in cytochrome bo3) and R439 (R482 in bo3) and its hydrogen bond interaction with R438 (or Q438)
| Strain (Cyt bo3 numbering) | Predicted stabilization, pKa units
|
Proton translocation (see Table 1) | |||
|---|---|---|---|---|---|
| Charge interaction
|
Hydrogen bond | Sum | |||
| With R481 | With R482 | ||||
| Wild type | 11 | 6.5 | 5 | 22.5 | Yes |
| R481Q | 0 | 6.5 | 5 | 11.5 | Yes |
| R481N, L | 0 | 6.5 | 0 | 6.5 | No |
| R482Q, N, L | 11 | 0 | 5 | 16 | Yes |
| R481Q/R482Q | 0 | 0 | 5 | 5 | No |