Coordination Chemistry of Microbial Iron Transport

• DOI: 10.1021/acs.accounts.5b00301
• Publication Date: 2015-09-02T17:06:22Z
• Authors: Kenneth N. Raymond; Benjamin E. Allred; Allyson K. Sia
• Keywords: Coordination complex

ConspectusThis Account focuses on the coordination chemistry of microbial iron chelators called siderophores. The initial research (early 1970s) focused simple analogs siderophores, which included hydroxamate, catecholate, or hydroxycarboxylate ligands. subsequent work increasingly transport siderophores and their transport. Since these are pseudo-octahedral complexes often composed bidentate ligands, there is chirality at metal center that in principle independent ligand chirality. It has been shown many cases chiral recognition complex occurs. Many techniques have used to elucidate uptake processes both Gram-positive (single membrane) Gram-negative (double bacteria. These use radioactive labels (of ligand, metal, both), kinetically inert complexes, Mössbauer spectroscopy. In general, siderophore involves receptors recognize chelate portion iron–siderophore complex. A second, date less commonly found, mechanism shuttle receptor binding an apo-siderophore.Since one primary ways microbes compete with each other for stores strength competing it became important early characterize solution thermodynamics species. acidity varies significantly, just stability constant does not give a direct measure relative competitive binding. For this reason, pM value compared. pM, like pH, negative log free ion concentration, typically calculated pH 7.4, standard total concentrations ligand. characterization electronic structure ferric done much help explain high complexes.A new chapter science emerged what now siderocalins. Initially found as protein human innate immune system, proteins bind apo-siderophores inactivate system hence deny invading pathogenic microbe. Siderocalins also can play role host, particularly stages fetal development. Finally, speculated molecular targets siderocalins different species differ based structures most bacterial pathogens those