Iron-siderophore complex

The **iron-siderophore complex** is a chemical entity formed when a siderophore, a small high-affinity iron-chelating compound secreted by microorganisms, binds ferric iron (Fe(III)). This complex enables otherwise insoluble iron to be solubilized and transported into bacterial cells through specialized receptor-mediated uptake systems, mainly found in the outer membrane of Gram-negative bacteria[1][2][4][5][6]. The structural diversity of siderophores arises from distinct chelating groups (catecholates, hydroxamates, carboxylates), but all serve the function of scavenging iron from the environment. The iron-siderophore complex is recognized and imported by specific **TonB-dependent transporters** or similar proteins on the bacterial cell surface[4][6]. Inside the cell, iron is reduced and released for metabolic use, and the siderophore may be recycled or degraded[1][2]. Because iron acquisition is essential for bacterial survival and pathogenesis, the corresponding transporters/receptors (not the complex itself) are attractive antimicrobial drug targets, and "Trojan horse" antibiotics use the siderophore pathway for targeted drug delivery[6]. Essential clarification: *Iron-siderophore complex* describes a molecular assembly critical to bacterial iron uptake—highly relevant in microbiology and infection biology but should not be mistaken for a protein, receptor, or classical therapeutic target. Most drugs target the associated transport proteins, not the complex itself.

Other names

Ferric-siderophore complexFe(III)-siderophore complexferri-siderophore complex

Drug "hijacking" (drugs conjugated to siderophores are transported into bacteria via iron-siderophore uptake system), Inhibition of iron acquisition pathways