Domain preference in iron removal from human transferrin by the bacterial siderophores aerobactin and enterochelin

The ability of the siderophores aerobactin and enterochelin to remove iron from transferrin is reported. Aerobactin removes iron from both high-affinity sites on the transferrin molecule, but shows a marked preference for the C-terminal site. This preference is different to that of many iron chelators. Enterochelin removes iron perferentially from the N-terminal site. No evidence for synergism between aerobactin and bidentate ligands could be detected.