Table 1. Properties of P. denitrificans cNOR variants at the entrance of proton pathway 1.
Data from this study is highlighted in bold, other data is from Ref. [7]. PW = pathway. Conservation and location from Ref. [7].
| Res. in P. aer. (conservation) Location | Mutation in P. den. | Spectra | Maximum turnover activity with NO (e-/s) (% of WT activity) a) | CO binding b) τ1 (μs)/ τ2 (μs) (% τ2) c) | O2 b) binding τ (μs) | ETPT d) τ (ms) at pH 7.5 |
|---|---|---|---|---|---|---|
| WT P. den. | Normal | 8.8 ± 0.2 (100%) | 14±4/130±10 (58±2%) | 44 ± 2 | 17 ± 4 | |
| E57C (77% E, rest Q,H,D) Entrance proton PW 1 | E58CQ P. den. | Normal | 0.7 ± 0.0 (8%) | 11±1/144±5 (49±1%) | 42 ± 2 | 510 ±50 |
| E57C (77% E, rest Q,H,D) Entrance proton PW 1 | E58CD P. den. | Normal | 2.0 ± 0.2 (23%) | 4±3/120±20 (62±1%) | 70±10 | 102 ± 2 |
| K53C (100%K) Entrance proton PW 1 | K54CA P. den. | Normal | 1.5 ± 0.1 (17%) | 18±2/170±20 (62±2%) | 40±2 | 250 ±80 |
a) At pH 7.5 and 303K. The average and the range of at least two different measurements is indicated.
b) At 1 mM CO or O2, pH 7.5 and T = 295K. The average of at least two independent experiments is given with the standard deviation (for wildtype, N>6 and E58cD and K54cA: N = 3) or with the range (N = 2).
c) % τ2 indicates the % of the total amplitude that is associated with the second phase at 430 nm.
d) Proton-coupled electron transfer during O2 reduction. The average of at least two independent experiments is given with the standard deviation (for wildtype, N = 12) or with the range (N = 2 or 3).