Staphylococcus lugdunensis is often found as part of the normal flora of human skin but has the potential to cause serious infections even in healthy individuals. It remains unclear what factors enable S. lugdunensis to transition from a skin commensal to an invasive pathogen. Analysis of the complete genome reveals a putative iron-regulated surface determinant (Isd) system encoded within S. lu...

The hmuO gene is required for the utilization of heme and hemoglobin as iron sources by Corynebacterium diphtheriae. The product of hmuO has homology to eukaryotic heme oxygenases which are involved in the degradation of heme and the release of iron. To investigate the mechanism of hmuO regulation, a promoterless lacZ gene present on the promoter-probe vector pCM502 was placed under transcripti...

Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme...

The bacterioferritin (BFR) of Escherichia coli is a heme-containing iron storage molecule. It is composed of 24 identical subunits, which form a roughly spherical protein shell surrounding a central iron storage cavity. Each of the 12 heme moieties of BFR possesses bis-methionine axial ligation, a heme coordination scheme so far only found in bacterioferritins. Members of the BFR family contain...

Pseudomonas aeruginosa, an opportunistic pathogen, requires iron for virulence and can obtain this nutrient via the acquisition of heme, an abundant source of iron in the human body. A surplus of either iron or heme can lead to oxidative stress; thus, the Fur (ferric uptake regulator) protein blocks expression of genes required for iron and heme uptake in iron-replete environments. Fur also rep...

Red meat intake has been linked to increased colorectal cancer (CRC) risk. Although the underlying mechanisms remain unclear, experimental studies suggest a role for dietary heme iron. Because heme iron was shown to promote specific mutations, it would be insightful to link heme iron data to CRC with mutations in key genes in an observational, population-based study. We investigated the associa...

Commercial elemental iron powders (electrolytic and reduced iron), as well as heme iron supplements, were tested for efficacy in improving the iron status of women. In a randomized, double-blind trial, 51 women with moderate to low iron stores received daily for 12 wk: 1) placebo, 2) 5 mg iron as heme iron or 50 mg iron as 3) electrolytic iron, 4) reduced iron, or 5) FeSO(4). Treatments were pr...

Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to ...

Iron is essential for replication of Mycobacterium tuberculosis, but iron is efficiently sequestered in the human host during infection. Heme constitutes the largest iron reservoir in the human body and is utilized by many bacterial pathogens as an iron source. While heme acquisition is well studied in other bacterial pathogens, little is known in M. tuberculosis To identify proteins involved i...

BACKGROUND Quantitative data on the mucosal uptake and serosal transfer of nonheme-iron absorption in humans and the effects of calcium on these components are limited. OBJECTIVE Our objective was to measure the initial mucosal uptake and the subsequent serosal transfer of nonheme iron and to determine the effects of adding calcium to a meal on both heme- and nonheme-iron retention. DESIGN ...