| [H2O2] (μM) | | Oxidation at steady state (5 min)b | kswitch-off (s− 1)c |
---|
Strain | Extracellular | Intracellulara | Gradient | OxyR | Tpx1 | OxyR | Tpx1 |
---|
Δtrx1
| 2 | 0.048 | 42 | 28% | | 0.017 | |
Δtrx1
| 5 | 0.12 | 42 | 89% | | 0.002 |
Δtrx3
| 20 | 0.12 | 160 | 24% | | 0.056 |
Δtrx3
| 50 | 0.31 | 160 | 77% | | 0.013 |
Wild type | 20 | 0.075 | 267 | 17% | 46% | 0.050 | 0.85 |
Wild type | 50 | 0.19 | 267 | 58% | 71% | 0.019 | 0.79 |
- aIntracellular concentration of H2O2 is calculated from the gradients between extracellular and intracellular H2O2 concentration determined from OxyR oxidation profiles
- bThe oxidation values for OxyR are extracted from experiments like those in Additional file 2: Figure S2 and the fitting shown in Additional file 3: Figure S3a, while Tpx1 oxidation values are an average of several biological replicates of experiments, like those of Additional file 2: Figure S2b
- cThe pseudo-first-order rate constant characterizing the reduction of thiol proteins is determined from the steady-state Eqs. 2 and 3, assuming that the second-order rate constants for the reaction of H2O2 with Tpx1 and OxyR are 1 × 107 M− 1 s− 1 and 1.4 × 105 M− 1 s− 1, respectively