Iron storage

The tight control of iron metabohsm is crucial for health, because not only iron deficiency but also iron overload is closely related to human diseases. Excess of cellular iron is stored and detoxified in ferritin. Ferritins are ubiquitous, highly conserved iron storage proteins which play a critical role in cellular and 

Iron stored in ferritin ean be mobilized during iron deficiency for metabolic needs, but the meehanism is incompletely characterized. Two models regarding iron exit and re-utilization have been proposed they are lysosome-mediated protein degradation and iron-releasing model and ferritin pores at the junetions of ferritin subunits as iron channel mediating iron release model. 

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Ferritin is a globular iron-storage protein that stores iron as FeJ+. To leave the ferritin, Fe3+ must first be reduced to Fe2+. Ferritin has two types of channels through which the Fe"+ could leave a three-fold channel and a four-fold channel. The three-fold channel is lined with the amino acids aspartate (Asp) and glutamate (Glu) and the four-fold channel is lined with the amino acid leucine (Leu). Through which channel is the Fe + more likely to leave the ferritin protein Explain your answer. 

Use iron complex former (for therapy of iron storage diseases)... 

Schematic representation of ferritin, the iron storage protein, (a) The protein contains 24 neariy identical polypeptides, (b) A ribbon stmcture of one of the polypeptide chains.

C20-0105. The iron storage protein ferritin usuaiiy is neither empty of iron nor fiiied to capacity. Why is this situation advantageous for an organism ... 

Alkaline Nickel-Cadmium (Iron) Storage Batteries... 

Richter, G.W. (1978). The iron-loaded cell - the cytopathology of iron storage. A review. Am. J. Pathol. 91, 363—404. 

Peters, S.W., Jones, B.M., Jacobs, A. and Wagstaff, M. (1985). Free iron and lipid peroxidation in the plasma of patients with iron overload. In Proteins of Iron Storage and Transport (eds. G. Spik, J. Montreuil, R.R. Crichton and J. Mazurier) pp. 321-324. Elsevier Science Publishers, New York. 

Figure 6.13 shows the Mossbauer spectra of ferritin [51], which is an iron-storage protein consisting of an iron-rich core with a diameter around 8 nm with a structure similar to that of ferrihydrite and which is surrounded by a shell of organic material. At 4.2 K essentially all particles contribute to a magnetically split component, but at higher temperatures the spectra show the typical superposition of a doublet and a sextet with a temperature dependent area ratio. At 70 K the sextet has disappeared since all particles have fast superparamagnetic relaxation at this temperature. 

Serum ferritin Less than 1 0-20 mcg/L (22-44 pmol/L) Ferritin is the protein-iron complex found in macrophages used for iron storage low in iron-deficiency anemia. 

Serum ferritin A complex protein formed in the intestine, containing about 23% iron, the amount of ferritin found in serum is directly related to iron storage in the body. 

Finally, animal, plant and microbial tissues have been shown to contain the iron storage protein ferritin. The animal protein has been extensively studied, but the mechanism of iron binding has not been completely resolved (29). Animal tissues contain, in addition, a type of granule comprised of iron hydroxide, polysaccharide and protein. The latter, called hemosiderin, may represent a depository of excess iron (30). Interestingly, a protein with properties parallel to those of ferritin has been found in a mold. Here the function of the molecule can be examined with the powerful tools of biochemical genetics (31). 

The core of the iron storage protein ferritin consists of a hydrated ferric oxide-phosphate complex. Various models have been proposed which feature Fe111 06 oct., Fe111 O4 tet. or Fe111 O4 tet. Fe111 06 oct. complexing the first listed is preferred by Gray (99) on the basis of the electronic absorption spectrum. The protein very closely related to ferritin which occurs in the mold Phycomyces blakesleeanus contains... 

Saccharomyces cerevisiae 85 copper uptake 290 iron storage 100 zinc uptake 295 scandium 108 selenium xvii... 

In the absence of a demonstrable yeast iron-storage protein (ferritin), we have to recognize that, despite our substantial advances in understanding iron uptake in yeast, we know practically nothing about intracellular iron metabolism - except that is for iron transport into, and out of, mitochondria. 

It has been suggested (Bozzi et ah, 1997 Grant et ah, 1998) that Dps and E. inocua ferritin represent examples of a family of ancestral dodecameric protein which had as function to trap, but not to mineralize, metal ions, and that the ability to oxidize and mineralize iron efficiently and to form fourfold interactions came later. The hollow-cored dodecameric motif exemplified by Dps and E. inocua ferritin has clearly been adapted to a number of functions, since in addition to DNA binding and iron storage, other family members include a novel pilin, a bromoperoxidase and several other proteins of unknown function (Grant et ah, 1998). 

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