We examined the bioavailability of iron-storage proteins—including representatives of maxiand miniferritins—to various species of marine phytoplankton. Both eukaryotic and prokaryotic species were able to grow rapidly with horse spleen ferritin (HoSF) or deoxyribonucleic acid (DNA)-binding proteins from starved cells (Dps) from Trichodesmium erythraeum as the sole Fe source in the medium. In th...

I n mammalian cells, iron is required for the function of many prosthetic groups, including heme and iron-sulfur clusters. Mammals absorb dietary iron and heme across the apical mucosa of duodenal epithelial cells using a Fe transporter known as divalent metal transporter 1 (DMT-1; also known as solute carrier family 11 member 2, divalent cation transporter 1 (DCT1), and natural resistance asso...

Iron oxide catalysts supported on nanostructured silica SBA-15 were synthesized with various iron loadings using two different precursors. Structural characterization of the as-prepared Fe x O y /SBA-15 samples was performed by nitrogen physisorption, X-ray diffraction, DR-UV-Vis spectroscopy, and Mössbauer spectroscopy. An increasing size of the resulting iron species correlated with an increa...

[Fe-Fe]-hydrogenases are enzymes that reversibly catalyze the reaction of protons and electrons to molecular hydrogen, which occurs in anaerobic media. In living systems, [Fe-Fe]-hydrogenases are mostly used for H(2) production. The [Fe-Fe]-hydrogenase H-cluster is the active site, which contains two iron atoms. The latest theoretical investigations1,2 advocate that the structure of di-iron air...

We report that the (Ba,K)Fe(2)As(2) superconductor (transition temperature, T(c) approximately 38 K) has an inverse iron isotope coefficient alpha(Fe) = -0.18(3) (where T(c) approximately M(-alphaFe) and M is the iron isotope mass); i.e., the sample containing the large iron isotope mass depicts a higher T(c). Systematic inverse shifts in T(c) were clearly observed between the samples using thr...

Waterborne iron accumulation by the gills of the zebrafish Danio rerio was assessed in ion-poor water. Branchial iron uptake, which comprises both the iron that has entered the gill cells and iron that is strongly bound to the epithelia, has high- and low-affinity components. At low nominal [Fe] (<40 nmol l(-1)) the high-affinity component demonstrated saturation kinetics, with an apparent K(m)...

The cells of the green unicellular alga Scenedesmus incrassatulus Böhl, strain R-83 released organic chelators for Fe(III) in inorganic nutrient medium both in iron-deficient and in iron-replete conditions. Iron-deficient cells released chelators capable to bind 11nmol Fe. mg (cell DW)–1.h–1, while the chelators released from iron-sufficient cells after contact with Fe(III) were sufficient to b...

To achieve cellular iron deprivation by chelation, it is important to develop chelators with selective metal-binding properties. Selectivity for iron has long been the province of certain oxygen-donor chelators such as desferrioxamine, which target Fe(III) and exploit the strength of a relatively ionic Fe(III)-O interaction. We have been studying novel chelators that possess mechanisms to selec...

Laser-evaporated iron was deposited onto solid oxygen at 20 K to produce stratified samples consisting of Fe and 02 layers. The Mossbauer spectra of these samples were acquired in order too investigate their oxidation states and chemical properties. The reaction produced the trivalent iron oxide particles whose size varied depending on the amount of Fe atoms deposited on the solid oxygen. Sampl...

The origin of previously observed variations in stoichiometry of iron oxidation during the oxidative deposition of iron in ferritin has been poorly understood. Knowledge of the stoichiometry of Fe(II) oxidation by O2 is essential to establishing the mechanism of iron core formation. In the present work, the amount of Fe(II) oxidized was measured by Mössbauer spectrometry and the O2 consumed by ...