Members of the genus Shewanella translocate deca- or undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/egress sites arranged within four domains. Seque...

The mechanism by which Paracoccus denitrificans utilizes parabactin in its iron-transport apparatus is examined. The cellular uptake of 55Fe-parabactin, its enantiomer, as well as a large number of its homologues and analogues are measured. Furthermore, the ability of these catecholamide ligands to stimulate microbial growth is also determined. The results of these studies point out several str...

Bidentate hydroxypyridinone chelators effectively complex and facilitate excretion of trivalent iron. To test the hypothesis that hexadentate chelators are more effective than bidentate chelators at low concentrations, urinary and biliary Fe excretions were determined in Fe-loaded rats before and after administration of a bidentate chelator, Pr-(Me-3,2-HOPO), or its hexadentate analogue, TREN-(...

Desferrioxamine, widely used for the treatment of iron overload in Cooley's anaemia, binds iron so tightly that it should quantitatively remove iron from transferrin. Studies conducted in vivo and in vitro, however, have failed to demonstrate significant depletion of transferrin-bound iron by a stoichiometric excess of desferrioxamine. However, low molecular weight chelating agents, capable of ...

Attention is devoted to the role of chelating agents in the treatment of aluminium related diseases. In fact, in spite of the efforts that have drastically reduced the occurrence of aluminium dialysis diseases, they so far constitute a cause of great medical concern. The use of chelating agents for iron and aluminium in different clinical applications has found increasing attention in the last ...

Lime-induced iron chlorosis in citrus and avocado trees may be controlled by chelating agents, such as EDTA-ethylene-diaminetetraacetic acid. Chelating agents have the ability to form complex compounds with metal ions-iron, zinc, manganese, and magnesium-holding the metals in a soluble form in various degrees of tenacity. Iron is held most firmly and, for this reason, the prospects may be best ...

The chemistry of sites that specifically bind Rb in Chlorella pyrenoidosa has been investigated by changing or modifying specific chemical groups or bonds in the cell and observing changes in binding capacity. Boiling the cells in water or in 70 per cent ethanol did not affect binding capacities of the sites. These results suggest that the integrity of the sites is independent of both hydrogen ...