Abnormal deposition of hemichrome on the inner aspect of the sickle red cell membrane promotes premature cell demise. The steps proximate to hemichrome formation in these cells are poorly understood. To test the hypothesis that the pathologic deposits of free ferric iron located on the inner aspect of sickle cell membranes would be redox active and promote oxidation of soluble oxyhemoglobin, we...

Many bituminous coal mine effluents contain, along with other ions, high concentrations of ferrous iron. This is brought into solution by sulfuric acid produced by the oxidation of sulfuritic material, possibly iron sulfides in part, occurring with bituminous coal (Leathen et al., 1952). The ferrous iron is oxidized by bacteria to the ferric state at a more rapid rate than can be accounted for ...

It is widely accepted that iron deposition in the iron storage protein ferritin in vitro involves Fe(II) oxidation, and that ferritin facilitates this oxidation at a ferroxidase site on the protein. However, these views have recently been questioned, with the protein ferroxidase activity instead being attributed to autoxidation from the buffer alone. Ligand exchange between another protein with...

Were Oscar Wilde a devotee of iron biogeochemistry in the twenty-first century (hard as that might be to imagine), he might remark that iron is the most ironic of elements. Those interested in microbes that carry out life-sustaining iron-coupled redox reactions like to point out that iron is, after oxygen, the most abundant redox-active element in the Earth’s crust. However, those studying ocea...

iron is a pro-oxidant cofactor that may be linked to atherosclerosis progression. free iron catalyzes the generation of free radicals and free radicals promote the oxidation of lipids. reduction of body iron stores secondary to blood donation has been hypothesized to reduce lipid peroxidation. the aim of this study was to evaluate the association between blood donation and antioxidant enzymes a...

The conventional model of oxidative DNA damage posits a role for superoxide (O2-) as a reductant for iron, which subsequently generates a hydroxyl radical by transferring the electron to H2O2. The hydroxyl radical then attacks DNA. Indeed, mutants of Escherichia coli that lack superoxide dismutase (SOD) were 10-fold more vulnerable to DNA oxidation by H2O2 than were wild-type cells. Even the pa...

Iron particle coating can improve the behavior of magnetorheological elastomers (MREs) by inhibiting iron particle rusting; however, such a process can change physical properties of MREs such as oxidation resistance, shear modulus, and stiffness change due to an applied magnetic field. In this study, MRE samples are fabricated with regular and polymerized iron particles. To investigate the poss...

Oxidation of serum proteins can lead to carbonyl formation that alters their function and is often associated with stress-related diseases. As it is recommended that all pigs reared in modern production facilities be given supplemental iron at birth to prevent anemia, and metals can catalyze the carbonylation of proteins, the primary objective of this study was to determine whether standard iro...

The mechanisms of early diagenetic quartz formation under low-temperature conditions are still poorly understood. In this study we investigated lithified cherts consisting of microcrystalline quartz recovered near the base of a 420 m thick Miocene-Holocene sequence of nannofossil and diatom ooze at a drill site in the Eastern Equatorial Pacific (Ocean Drilling Program Site 1226). Precipitation ...

Thiobacillus ferrooxidans is found in many Alaskan and Canadian drainages contaminated by metals dissolved from placer and lode gold mines. We have examined the iron-limited growth and iron oxidation kinetics of a T. ferrooxidans isolate, AK1, by using batch and continuous cultures. Strain AK1 is an arsenic-tolerant isolate obtained from placer gold mine drainage containing large amounts of dis...