Figure 2.
Human ferroportin preferably transports Fe2+over other divalent metal ions. (A) Transport activity of Co2+, Ni2+, and Mn2+ using the calcein-based assay (as in Figure 1). Addition of these divalent metal ions is indicated above the curves. All metal ions are provided at the concentration of 100 μM. (B) Comparison of the apparent KM of ferroportin-mediated transport of different metal ions, with the y-axis break at 0.1 μM. (C) Competition of other divalent ions (Zn2+, Cd2+, Ca2+, and Mg2+) against Fe2+ transport. Fe2+ and the competing metal ions are provided at the concentrations of 10 μM and 100 μM, respectively.