Iron mobilization from transferrin by therapeutic iron chelating agents

► Human transferrin binds two iron(III) ions with slightly different affinities. ► Negatively charged chelators (pFe ≥ 20) can remove iron from transferrin. ► Chelators have different abilities to scavenge iron from the 2 binding sites. ► Some siderophores can remove iron from the transferrin. ► Chelators (pFe ≈ 20) can both remove and donate iron from and to transferrin.