Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The NMR relaxation technique was used to investigate the permeation of molecules into the cavity of ferritin. Spin-lattice relaxation times in the rotating frame of various probe molecules were measured for solutions of recombinant horse L-apoferritin without iron and horse spleen apoferritin with very small amounts of ferric ions. The results show that molecules larger than the size of the ferritin channels can pass through the channels into the ferritin interior, and that the maximum size of molecules for the permeation is smaller than maltotriose.
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PMID:Permeation of small molecules into the cavity of ferritin as revealed by proton nuclear magnetic resonance relaxation. 771 84

The DNA-binding proteins from starved cells (Dps) are a family of proteins induced in microorganisms by oxidative or nutritional stress. Escherichia coli Dps, a structural analog of the 12-subunit Listeria innocua ferritin, binds and protects DNA against oxidative damage mediated by H(2)O(2). Dps is shown to be a Fe-binding and storage protein where Fe(II) oxidation is most effectively accomplished by H(2)O(2) rather than by O(2) as in ferritins. Two Fe(2+) ions bind at each of the 12 putative dinuclear ferroxidase sites (P(Z)) in the protein according to the equation, 2Fe(2+) + P(Z) --> [(Fe(II)(2)-P](FS)(Z+2) + 2H(+). The ferroxidase site (FS) bound iron is then oxidized according to the equation, [(Fe(II)(2)-P](FS)(Z+2) + H(2)O(2) + H(2)O --> [Fe(III)(2)O(2)(OH)-P](FS)(Z-1) + 3H(+), where two Fe(II) are oxidized per H(2)O(2) reduced, thus avoiding hydroxyl radical production through Fenton chemistry. Dps acquires a ferric core of approximately 500 Fe(III) according to the mineralization equation, 2Fe(2+) + H(2)O(2) + 2H(2)O --> 2Fe(III)OOH((core)) + 4H(+), again with a 2 Fe(II)/H(2)O(2) stoichiometry. The protein forms a similar ferric core with O(2) as the oxidant, albeit at a slower rate. In the absence of H(2)O(2) and O(2), Dps forms a ferrous core of approximately 400 Fe(II) by the reaction Fe(2+) + H(2)O + Cl(-) --> Fe(II)OHCl((core)) + H(+). The ferrous core also undergoes oxidation with a stoichiometry of 2 Fe(II)/H(2)O(2). Spin trapping experiments demonstrate that Dps greatly attenuates hydroxyl radical production during Fe(II) oxidation by H(2)O(2). These results and in vitro DNA damage assays indicate that the protective effect of Dps on DNA most likely is exerted through a dual action, the physical association with DNA and the ability to nullify the toxic combination of Fe(II) and H(2)O(2). In the latter process a hydrous ferric oxide mineral core is produced within the protein, thus avoiding oxidative damage mediated by Fenton chemistry.
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PMID:Iron and hydrogen peroxide detoxification properties of DNA-binding protein from starved cells. A ferritin-like DNA-binding protein of Escherichia coli. 1201 14

Seventeen non-transfusion-dependent Chinese haemoglobin H (Hb H) disease patients (age 29-76 years) with serum ferritin >900 microg/l were treated with deferiprone for up to 18 months. One patient withdrew and data from 16 patients were analysed. Sixteen other Hb H patients with ferritin <900 microg/l, matched for age and genotype, acted as controls. Treatment was well tolerated except for mild arthralgia. Serum ferritin fell with treatment, reaching significance at 6 and 18 months (from 1492.3 +/- 901.4 to 519.4 +/- 405.4 microg/l at 18 months, P = 0.0008). Nine of 16 patients had levels below 397 microg/l before 18 months. Serum ferritin remained stable 6 months after stopping treatment. In contrast, there was no change in ferritin levels in the control group. Magnetic resonance imaging was used for measurement of liver iron content. Spin echo T(1)-signal intensity ratio (T(1)-SIR) and gradient echo T(2)-signal intensity ratio (T(2)-SIR) increased with treatment. T(2)-SIR rose from 0.17 +/- 0.08 pretreatment to 0.58 +/- 0.50 at 2 years (P = 0.0055). Improvement occurred in 12 of 16 patients, reaching normal in three patients. Using echocardiography, peak early diastolic : late diastolic blood flow (E/A) remained unchanged with treatment, but isovolumic relaxation time (IVRT) was prolonged at 2 years indicating mild impairment of diastolic function. All systolic function parameters were normal. A longer treatment period is desirable to demonstrate improvement in cardiac function.
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PMID:Use of the oral chelator deferiprone in the treatment of iron overload in patients with Hb H disease. 1661 12

The purpose of this study is to describe the MR imaging features of bone marrow in beta-thalassemia major and investigate their relation to ferritin, liver and spleen siderosis. Spinal bone marrow was prospectively assessed on abdominal MR studies of 40 transfused beta-thalassemic patients and 15 controls using T1-w, Pd, T2*-w Gradient Echo (GRE) and T1-w turbo Spin Echo (TSE) sequences. Signal intensity (SI) ratios of liver, spleen and bone marrow to paraspinous muscles (L/M, S/M, B/M respectively) and the respective T2 relaxation rates (1/T2) were calculated. Serum ferritin levels were recorded. Bone marrow hypointensity in at least T2*-w GRE sequence was noted in 29/40 (72.5%) patients. Eleven/40 patients exhibited normal B/M on all MR sequences. Five/40 patients had normal B/M and low L/M. B/M correlated with L/M in T1-w TSE sequence only (r = 0.471, p = 0.05). B/M correlated with S/M and mean ferritin values in all sequences (r > 0.489, p < 0.01 and r > - 0.496, p < 0.03 respectively). Marrow 1/T2 did not correlate with ferritin values or liver and spleen 1/T2. B/M in transfused beta-thalassemic patients is related to splenic siderosis and ferritin levels. Although marrow is usually hypointense, it may occasionally display normal SI coexisting with liver hypointensity, a pattern typical of primary hemochromatosis.
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PMID:Bone marrow changes in beta-thalassemia major: quantitative MR imaging findings and correlation with iron stores. 1718 Mar 27

The patients of thalassaemia major need repeated blood transfusion which leads to excess iron deposition in various organs like liver, heart, pituitary etc. This iron accumulation causes various complications and ultimately organs' failure. There is no non-invasive, standard and reliable method to know the status of iron overload in various organs of the body. This paper attempts to use magnetic resonance imaging to know the liver iron overload in 8 thalassaemic patients as a pilot study. Eight children suffering with thalassaemia and 3 controls who were the normal siblings of the patient group underwent magnetic resonance imaging of the abdomen using spin-echo T, weighted sequence. Blood serum ferritin levels in the patients' group were also determined on the same day of magnetic resonance imaging examination. It was observed that the ratio of magnetic resonance imaging signal intensity (in spin-echo T1 weighted image) in paraspinous muscle to liver was significantly different in normal control (0.65) compared to that in thalassaemia patients (2.1 to 11.4 depending upon extent of iron deposition). The magnetic resonance signal intensity ratio correlated with the blood serum ferritin level of patients (p = 0.01) which is generally taken as indirect measure of body iron burden. Spin-echo sequence is the simplest imaging sequence and it increases the chance of its routine use. The study concludes that magnetic resonance imaging has good potential to quantify the liver iron deposition non-invasively and may denote the efficacy of iron-chelation therapy which is used to reduce the body iron burden in these patients.
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PMID:Assessmrent of iron overload in thalassaemic patients by magnetic resonance imaging: a pilot study. 1838 51