Table 1.
The Rate Constants for PT in the WT ClC-ec1 and E203K Mutant
| Cl−cen | PMF | k (μs−1) | ΔF‡ (kcal/mol) | |
|---|---|---|---|---|
| WT | Present | Fig. 3A | (3.8 ± 1.8) × 102 | 5.1 |
| Fig. 3B | (6.4 ± 1.5) × 102 | 5.9 | ||
| Absent | Fig. 4A | 0.71 ± 0.25 | 10.2 | |
| Fig. 4B | 0.24 ± 0.09 | 10.9 | ||
| E203K | Present | Fig. 6A | (2.3 ± 0.3) × 102 | 11.4 |
| Fig. 6B | 1.2 ± 0.2 | 9.4 | ||
| Absent | Fig. 6C | (7.0 ± 0.7) × 10−9 | 20.4 | |
| Fig. 6D | (1.9 ± 0.9) × 10−2 | 12.0 |
The rate constants were calculated with transition state theory. Error in the rate constant was estimated using the block average method by calculating the rate constant in four consecutive blocks in the trajectories for each window. The experimental value for proton permeation rate in the WT protein is (1.0 ± 0.1) × 10−3μs−1 (34), while that for E203K is ∼3 times slower (27).