Time dependence of Fe transfer from L1 to Fl-DFO.

Preformed L1-Fe complexes containing 2 μM Fe and increasing concentrations of L1 (0-16 μM) were prepared from Fe:NTA and L1 as described in Figure 4. At 0 minute, 20 μL of each solution was mixed with 100 μL 2.5 μM Fl-DFO in HBS, and the fluorescence was monitored with time. The final concentrations of both Fe and Fl-DFO were 2 μM in each system, whereas the concentration of L1 (μM) varied: ▪, 0; ●, 2; ▴, 4; ▾, 8; ♦, 16.