Table 2. Substrate Amounts Bound to YxeB by Exchange or Displacement with YxeB:DFO.
| metal–substrate added to YxeB:DFO [0.2 nmol/mL sample] | substrates bound to YxeB except DFO [nmol/mL sample] |
|---|---|
| ICP analysis for DFO:YxeB-L142-6×His complexa (Figure 3C) | |
| Ga-DFO | Ga-DFO, 0.155 (78%b) |
| FO | FO, 0.172 (86%b) |
| Cr-DFO | Cr-DFO, 0.014 (7%b) |
| ICP Analysis for DFO:YxeB-S142-6×His Complexa (Figure 3D) | |
| Ga-DFO | Ga-DFO, 0.165 (83%b) |
| FO | FO, 0.166 (83%b) |
| Cr-DFO | Cr-DFO, 0.022 (11%b) |
| RP-HPLC Analysis for DFO:YxeB-L142-6×His Complex (Figure 5 and Supporting Information Figure 6) | |
| AcFO | FO, 0.153 (77%b); AcDFO, 0.110 (55%c) |
| Fe-Ent | FO, 0.011 (≤5%b) |
| Fe-EDTA | FO, 0.003 (≤1%b) |
| Fch | FO, 0 (0%b); Fch, 0.037 (19%b) |
| Fe-Cit | FO, 0.089 (45%b) |
| hematin | FO, 0.003 (≤1%b) |
| RP-HPLC Analysis for DFO:YxeB-S142-6×His Complex (Supporting Information Figure 5) | |
| AcFO | FO, 0.144 (72%b); AcDFO, 0.089 (45%c) |
a
Substrate amounts bound to YxeB after 30 min incubation of YxeB;DFO with metal–substrate are shown.
b
Percentages are metal exchange rates or displaced substrate rates.
c
Percentages indicate rates of iron-released substrate remaining bound to YxeB.