Figure 5.

Synergistic anion competition for binding to apohTF. ApohTF was incubated in 25 mM (CO₃⁻²) with increasing concentrations of C₂O₄⁻² ranging from normal C₂O₄⁻² concentrations (1.8–4.7 μM) (7), ASD C₂O₄⁻² concentrations (3.5–7.5 μM) (7) and above (lanes 2–12 are 0, 1.0, 1.8, 2.5, 3.5, 4.7, 5.6, 7.5, 10, 25 and 50 μM C₂O₄⁻² respectively) in the presence of excess Fe³⁺. Samples were removed and electrophoresed following incubation with iron removal buffer (100 mM MES, pH 5.6, containing 300 mM KCl and 4 mM EDTA) for 15 min. The control carbonate (CO₃⁻²) and oxalate (C₂O₄⁻²) containing Fe₂hTF samples from Figure 1A are shown on the left as a reference.