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)

Three experiments involving 52 baby pigs were conducted to determine the minimum copper requirement of baby pigs fed purified diets. Diets were supplemented with anhydrous cupric sulfate to yield the following copper concentrations (ppm, by analysis) when the three experiments were combined: 0.6, 0.9, 1.3, 1.9, 2.0, 2.8, 3.2, 4.0, 4.9, 5.6 and 9.3. Parameters examined include weight gain, hematocrit, hemoglobin concentration, mean corpuscular hemoglobin concentration, plasma ceruloplasmin activity, plasma copper concentration, copper balance, brain and erythrocyte superoxide dismutase activity, copper concentration of liver, kidney, spleen, heart, brain, femur and hair, liver ferritin-iron and total iron concentration, strength characteristics of the femur, and gross and histological appearance at necropsy. Weight gains were subnormal at dietary copper concentrations below 1.9 ppm; plasma ceruloplasmin activities, and plasma and tissue copper concentrations were depressed at dietary copper levels below 2.8 ppm. Bone histopathology was evident at dietary copper levels below 3.2 ppm, and copper balance was low at dietary copper levels below 4.9 ppm. Some evidence of anemia was present at dietary copper levels below 5.6 ppm. Under the conditions of this study, the copper requirement of the baby pig fed a purified diet was judged to be approximately 5.6 ppm (6 ppm copper, dry basis).
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PMID:Copper requirement of baby pigs fed purified diets. 44 53

Factors related to iron metabolism were determined in 20 United States Navy divers during 8 d of air saturation-excursion hyperbaric exposures. During these simulated dives progressive and correlated increases in serum ferritin and iron occurred. No significant changes were observed in bilirubin, hemoglobin, ceruloplasmin, transferrin, copper, or total iron binding capacity. The significance of the increased serum ferritin is discussed in relation to bone marrow damage and early detection of aseptic bone necrosis.
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PMID:Changes in serum ferritin and other factors associated with iron metabolism during chronic hyperbaric exposure. 45 20

In an attempt to understand the variability of the hematologic response to oral sodium cyanate, iron metabolism was studied in a group of 39 patients with sickel cell disease. Eleven of the 39 patients were found to have no stainable iron in the marrow despite the fact that patients with sickle cell disease are generally considered to have hemosiderosis. The mean per cent saturation and total iron-binding capacity were in the low-normal range in sickle cell patients whether or not stainable iron was present in the bone marrow aspirate. Serum ferritin concentrations, on the other hand, were found to be high in both groups (greater than 500 mu g/liter) when compared to controls (60 mu g/liter). The high serum ferritin levels denoted significant total-body iron deposition which may be unavailable for normal metabolic processes. One patient with no stainable iron in the bone marrow aspirate did respond to iron therapy alone with an increase in hemoglobin concentration. Serum ceruloplasmin levels were also found to be high in sickle cell disease patients. The ability to respond to oral cyanate therapy was correlated with the amount of stainable iron in the bone marrow aspirate. These studies emphasize the necessity of a reevaluation of iron metabolism in the pathophysiology and treatment of sickle cell disease.
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PMID:Iron metabolism, sickle cell disease, and response to cyanate. 117 92

Fifty-nine thyroid tumors were re-examined and studied using immunohistochemistry to detect the presence of ceruloplasmin (CP), lactoferrin (LF), thyroglobulin, thyrocalcitonin, carcinoembryonic antigen and ferritin. In an attempt to study the contribution of the immunodetection of CP and LF in the diagnosis of malignant versus benign tumors, specially in follicular tumors, we compared our results of immunodetection with those of Tuccari and Barresi, and carried out our own studies on the usefulness of these immunolabelling. Concerning CP and LF staining, we have found the following data: 1) little (in contrast to Tuccari and Barresi) or no staining in normal thyroid and benign adenomas; 2) diffuse and intense staining in papillary and follicular carcinomas (as noted by the previous authors); 3) diffuse and weak staining for medullary carcinomas (in contrast to Tuccari and Barresi who found none). Our findings suggest that a diffuse and intense cytoplasmic staining with CP and LF concerning more than one third of all cells is a criterion of malignancy, whereas a weak paranuclear staining of a few cells is more in favor of a benign process.
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PMID:[Immunohistochemical demonstration of ceruloplasmin and lactoferrin in a series of 59 thyroid tumors]. 129 56

Recombinant H chain ferritins bearing site-directed amino acid substitutions at their ferroxidase centres have been used to study the mechanism of catalysis of Fe(II) oxidation by this protein. UV-difference spectra have been obtained at various times after the aerobic addition of Fe(II) to the recombinants. These indicate that the first product of Fe(II) oxidation by wild type H chain apoferritin is an Fe(III) mu-oxo-bridged dimer. This suggests that fast oxidation is achieved by 2-electron transfer from two Fe(II) to dioxygen. Modelling of Fe(III) dimer binding to human H chain apoferritin shows a solvent-accessible site, which resembles that of ribonucleotide reductase in its ligands. Substitution of these ligands by other amino acids usually prevents dimer formation and leads to greatly reduced Fe(II) oxidation rates.
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PMID:Mechanism of catalysis of Fe(II) oxidation by ferritin H chains. 135 23

Plasma zinc, copper, selenium, ferritin and whole blood manganese concentrations were measured in 22 children with kwashiorkor on admission to hospital and on days 5, 10 and 30 of refeeding. Twenty similarly aged, healthy, well nourished children served as controls. The mean (SEM) zinc, copper and selenium concentrations of 7.5 (0.93), 10.8 (0.64) and 0.29 (0.02) mumol/l, respectively, in the children with kwashiorkor on admission were all significantly lower than the values of 13.7 (0.66), 25.6 (1.72) and 0.72 (0.04) mumol/l in the controls. In contrast, the erythrocyte manganese level of 1.67 (0.09) micrograms/gHb and the median ferritin concentration of 293 micrograms/dl were significantly higher than in the controls. After 30 days there was full clinical recovery with significant weight gain and a return of the plasma albumin, caeruloplasmin, copper and ferritin to normal. However, manganese remained elevated and zinc and selenium concentrations remained significantly low. Our results suggest that nutritional rehabilitation of children with kwashiorkor is incomplete by 30 days and cannot be judged purely by a return of the plasma proteins to normal. Addition of selected trace elements to the diet may hasten full recovery.
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PMID:Plasma zinc, copper, selenium, ferritin and whole blood manganese concentrations in children with kwashiorkor in the acute stage and during refeeding. 137 81

The ferritins of animals and plants and the bacterioferritins (BFRs) have a common iron-storage function in spite of differences in cytological location and biosynthetic regulation. The plant ferritins and BFRs are more similar to the H chains of mammals than to mammalian L chains, with respect to primary structure and conservation of ferroxidase center residues. Hence they probably arose from a common H-type ancestor. The recent discovery in E. coli of a second type of iron-storage protein (FTN) resembling ferritin H chains raises the question of what the relative roles of these two proteins are in this organism. Mammalian L ferritins lack ferroxidase centers and form a distinct group. Comparison of the three-dimensional structures of mammalian and invertebrate ferritins, as well as computer modeling of plant ferritins and of BFR, indicate a well conserved molecular framework. The characterisation of numerous ferritin homopolymer variants has allowed the identification of some of the residues involved in iron uptake and an investigation of some of the functional differences between mammalian H and L chains.
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PMID:Structure, function, and evolution of ferritins. 143 78

A 55-year-old female with progressed dementia, cerebellar ataxia was reported. There was no family history of the same symptoms although her brothers, sisters and a son showed hypoceruloplasminemia and decrease of the serum copper content. On physical examination, anemia, dementia, dysarthria, torticollis, choreic involuntary movement of respiratory muscles, hyperreflexia in extremities and cerebellar ataxia were noted. Blood analysis revealed microcytic hypochromic anemia, diabetes mellitus, decrease of copper content of the serum and urine. Serum ferritin concentration was increased. Serum ceruloplasmin could not be detected. Biopsy of the liver showed that copper content in the liver was slightly increased and iron content was remarkably increased. On MRI study, dentate nucleus of the cerebellum, the thalamus, the putamen and the caudate nucleus and the liver showed low intensity in both T1 and T2 weighted images. Based on increased iron content in the liver, the radiological findings of the brain suggested deposition of iron in the brain. This deposition was considered as caused by deficiency of function of ceruloplasmin as ferroxidase. This disorder is suggested as a new disease due to ceruloplasmin deficiency different from Wilson's disease.
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PMID:[A case of ceruloplasmin deficiency which showed dementia, ataxia and iron deposition in the brain]. 145 25

Protein ferroxidase site(s), which catalyze the reaction between ferrous ion and dioxygen, have long been thought to play a role in core formation in ferritin; however, the mechanism of the reaction has never been studied in detail. In the present work, the enzymatic activity of ferritin was examined using oximetry, the net Fe2+ oxidation reaction being as follows. [formula: see text] The reaction exhibits saturation kinetics with respect to both Fe2+ and O2 (apparent Michaelis constants: Km,Fe = 0.35 +/- 0.01 mM and Km,O2 = 0.14 +/- 0.03 mM). The enzyme has a turnover number kcat = 80 +/- 3 min-1 at 20 degrees C with maximal activity at pH 7. The kinetics are discussed in terms of two mechanisms, one involving monomeric and the other dimeric iron protein complexes. In both instances Fe(II) oxidation occurs in 1-electron steps. Zinc(II) is a competitive inhibitor of iron(II) oxidation at Zn2+/apoprotein ratios > or = 6 (inhibitor constant KI,Zn = 0.067 +/- 0.011 mM) but appears to be a noncompetitive inhibitor at lower ratios (< or = 2), indicating the presence of more than one type of zinc binding site on the protein. At increments of 50 Fe2+/protein or less, all of the iron is oxidized via the protein ferroxidase site(s), independent of the amount of core already present. However, when larger increments are employed, some iron oxidation appears to occur on the surface of the mineral core. The results of these studies emphasize the role of the protein shell in all phases of core growth and confirm the presence of a functionally important catalytic site in ferritin in addition to other binding sites on the protein for iron.
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PMID:Ferroxidase kinetics of horse spleen apoferritin. 146 15

The ability to incorporate iron in vitro was studied in homopolymers of human ferritin L-chain, human ferritin H-chain and its variants and in homopolymer mixtures. The H-chain variants carried amino acid substitutions in the ferroxidase centre and/or in carboxy residues on the cavity surface. Iron incorporation was examined by gel electrophoresis of the reaction products by staining for iron and protein. It was found that inactivation of the ferroxidase centre combined with the substitution of four carboxy groups on the cavity abolished the ability of H-chain ferritin to incorporate iron. Competition experiments with limited amounts of iron showed that, at neutral pH, L-chain ferritin is more efficient in forming iron cores than the H-chain variants altered at the ferroxidase activity or in the cavity. Competition experiments at pH 5.5 demonstrated that L-chain apoferritin is able to incorporate iron only when in the presence of H-chain variants with ferroxidase activity. The results indicate that L-chain apoferritin has a higher capacity than the H-chain apoferritin to induce iron-core nucleation, whereas H-chain ferritin is superior in promoting Fe(II) oxidation. The finding of cooperative roles of the H- and L-chains in ferritin iron uptake provides a clue to understanding the biological function of isoferritins.
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PMID:Evidence of H- and L-chains have co-operative roles in the iron-uptake mechanism of human ferritin. 146 63


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