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

Reference serum copper, ceruloplasmin and zinc values were established for 100 healthy white nulliparous students aged 18-23 years resident in Cape Town who had been taking low-dosage triphasic contraceptives for a minimum period of 3 months, and in 100 female students not taking contraceptives. The mean serum copper values were 26.5 +/- 4.2 mumol/l and 16.9 +/- 2.7 mumol/l for those taking and not taking oral contraceptives respectively; corresponding values for ceruloplasmin were 181 +/- 43.9 IU/ml and 110 +/- 22.7 IU/ml respectively. Both differences were statistically significant. Serum zinc values for those on contraceptives were 14.1 +/- 2.1 mumol/l and for the others 14.7 +/- 2.0 mumol/l. There were no differences in the haematological parameters except for a significantly higher mean corpuscular volume in females taking oral contraceptives. Of possible clinical significance in this student population are prevalence rates of 2.2% for anaemia (haemoglobin value less than 11.5 g/dl), 7% for iron deficiency (serum ferritin less than 12 micrograms/l) and 6.6% for iron depletion (serum ferritin 12-20 micrograms/l).
 ...
PMID:Reference values for serum copper, ceruloplasmin and zinc and haematological indices for healthy nulliparous females. 366 Jan 57

Apoferritin catalyzes the oxidation of Fe(II) to Fe(III). Ferroxidase activity is assayed and characterized by coupling the oxidation with the binding of Fe(III) to transferrin. The initial rate of Fe(II) oxidation is dependent on apoferritin and initial Fe(II) concentration but independent of transferrin concentration. The ferroxidase activity is inhibited by Zn(II). Ferritins with varying loads of iron have the same ferroxidase activity level. It is suggested that the described oxidation process represents the initial step of iron deposition in apoferritin. Since transferrin can intercept Fe(III) before it is deposited in apoferritin, active sites for Fe(II) oxidation must be on or near the surface of apoferritin. This finding is contrary to the current view of apoferritin-catalyzed oxidation of Fe(II) which places active sites in the channels to the core or inside the central core.
 ...
PMID:Iron incorporation into apoferritin. The role of apoferritin as a ferroxidase. 375 57

This study systematically examined the characteristics of specific binding of adult diferric transferrin to its receptor using a Triton X-100 solubilized preparation from human placentas as the receptor source. The following information was obtained. The ionic strength for maximal binding is in the range of 0.1-0.3 M NaCl. The pH optimum for specific binding extends over the range, from pH 6.0-10.0. Specific binding of diferric transferrin is not affected by 2.5 approximately 50 mM CaCl2 or by 10 mM EDTA. Triton X-100 in the concentration range of 0.02-3.0% does not affect specific binding. Specific binding is saturated within 10 min at 25 or 37 degrees C in the presence of excess amounts of diferric transferrin. The binding is reversible and the dissociation of diferric transferrin from the transferrin receptor is complete within 40 min at 25 degrees C. Apotransferrin, both adult and fetal, showed less binding than the holotransferrin species by competitive binding assay in the presence of 10 mM EDTA independent of up to 20 mM CaCl2. A 1500-fold molar excess of adult and fetal apotransferrin is required to give 40% inhibition for 125I-labeled diferric transferrin binding. Since calcium ion is not a factor, and since apotransferrin has such high binding affinity for iron (Ka = 1 X 10(24], this experiment suggests that the EDTA was necessary to prevent conversion of apotransferrin to holotransferrin from available iron in the reaction system. The specificity of the transferrin receptor for transferrin was examined by competitive binding studies in which 125I-diferric transferrin binding was measured in the presence of a series of other proteins. The proteins tested in the competitive binding studies were classified into three groups; in the first group were human serum albumin and ovalbumin; in the second group were proteins containing iron ions, such as hemoglobin, hemoglobin-haptoglobin complex, heme-hemopexin complex, ferritin, and diferric lactoferrin; in the third group were the metal-binding serum proteins, ceruloplasmin and metallothionein. None of these proteins except ferritin showed inhibition of diferric transferrin binding to the receptor. The effect of ferritin was small since a 700- to 1500-fold molar excess of ferritin is required for 50% inhibition of binding of diferric transferrin to the receptor.
 ...
PMID:Characterization of transferrin binding and specificity of the placental transferrin receptor. 631 Nov 10

The effects on iron and copper distribution and metabolism of exposure to high levels of CO2 were studied in the guinea-pig. Mature, male animals were placed in an atmosphere of 15% CO2, 21% O2 (balance N2), and sacrificed from 1 h to 1 week thereafter. Total iron and copper concentrations of blood, liver, spleen and bone, as well as concentrations of heme and ferritin iron, were measured together with blood hematocrit, reticulocytes, plasma hemoglobin, plasma ceruloplasmin and copper concentrations. The results show clearly that rapid and sustained red cell damage or hemolysis ensued several h from the start of CO2 treatment. This resulted in loss of iron and copper from the blood, an influx of both elements into liver, spleen and bone, and a rise in plasma ceruloplasmin. Influx of iron into liver and spleen caused an accumulation of ferritin, the main site for iron storage in cells. Following the effect on red cells, there was an accumulation of heme iron, and a decreased hematocrit, best explained by a depressed activity of the reticuloendothelial and erythropoietic systems. A period of adaptation succeeded these events, in which all blood parameters and most tissue values returned to normal, despite the continuing presence of high CO2. The only changes not reversed were the elevations in liver, spleen and bone iron stores. These remained high, with a net accumulation of greater than 2 mg iron, or 3-4 times more than originally present. The results indicate that at least in the guinea-pig, high CO2 exposure results in red cell damage and other events leading to an accumulation of additional iron in the body; also, that iron accumulated as ferritin and hemosiderin in liver and spleen may not be readily available to restore blood hemoglobin concentrations on an acute basis.
 ...
PMID:Effects of CO2 exposure on distribution of various forms of iron and copper in guinea-pig tissues. 640 60

Ceruloplasmin, a copper ferroxidase, promotes the incorporation of Fe(III) into the iron storage protein, apoferritin. The product formed is identical to ferritin as judged by polyacrylamide electrophoresis and iron/protein measurements. Of several proteins examined, only apoferritin accumulates the Fe(III) produced by ceruloplasmin. When ceruloplasmin was replaced by tyrosinase, which we have shown to have ferroxidase activity, no iron incorporation into apoferritin was observed. It is proposed that Fe(III) is transferred directly and specifically to apoferritin. These data support a more specific role for ceruloplasmin in iron metabolism than has previously been proposed.
 ...
PMID:The incorporation of iron into apoferritin as mediated by ceruloplasmin. 641 53

The performance of different solid-phase luminescence immunoassays has been documented using four different assay concepts. These are CELIA (chemiluminescence immunoassay), SPALT (solid-phase antigen luminescence technique), ILMA (immunoluminometric assay) and ILSA (immunoluminometric labelled second-antibody assay). CELIA is analogous to a solid-phase radioimmunoassay and uses a labelled antigen, SPALT and ILSA use a labelled second (species-specific) antibody and ILMA a labelled substance-specific antibody, i.e. analogous to the immunoradiometric assay. Both bioluminescent and chemiluminescent labels have been used. Pyruvate kinase was used for bioluminescence and diazoluminol and N-(4-amino-butyl)-N-ethyl isoluminol hemisuccinamide for chemiluminescence. Relevant quality-control parameters and reference ranges have been given for the optimised assays. Assays described are: thyroxine, thyroxine binding globulin, cortisol, caeruloplasmin, ferritin and C-reactive protein. Luminescence immunoassays with coefficients of variation comparable with radioimmunoassay have been designed, values of under 5% being obtainable within the working range of the assay.
 ...
PMID:An evaluation of four different luminescence immunoassay systems: CELIA (chemiluminescent immunoassay), SPALT (solid-phase antigen luminescence technique), ILMA (immunoluminometric assay) and ILSA (immunoluminometric labelled second antibody). A critical study of macro solid phases for use in immunoassay systems, Part III. 643 36

Twelve voluntary adult subjects twice took a 30-min sauna bath, at a temperature of 80 degrees C with a 30-min rest between each, every 12 h for 1 week. Measurements of serum iron, copper, zinc, ferritin and ceruloplasmin were performed before the experiment, after the first and second 30 min in the sauna and at the end of the week. The first two sauna baths did not significantly change the concentrations of the trace elements measured. After the week the mean serum copper concentration had decreased from 15.0 (SD 1.7) mumol x 1-1 to 13.5 (SD 2.0) mumol x 1-1 (p less than 0.02). The mean zinc concentration decreased from 13.8 (SD 2.4) mumol x 1-1 to 9.8 (SD 1.8) mumol x 1-1 (p less than 0.001) during the week of the experiment. At the beginning of the study period two subjects had zinc concentrations below the reference values and after the week nine subjects had zinc concentrations below the reference values. The concentration of serum ferritin decreased from 142.2 (SD 103) micrograms x 1-1 to 111.3 (SD 89) micrograms x 1-1 (p less than 0.02) whereas the values of ceruloplasmin remained unchanged. Our findings confirm the earlier suggestion that heavy exposure to heat can cause a loss of some trace elements, especially zinc.
 ...
PMID:Serum iron, copper, zinc, ferritin, and ceruloplasmin after intense heat exposure. 668 31

Oxygen free radicals are probably involved in the pathogenesis of rheumatoid arthritis (RA). The enzymes involved in protection against oxygen free radicals and H2O2 (superoxide dismutase, catalase, and glutathione peroxidase) were measured. Superoxide dismutase was not increased, glutathione peroxidase was slightly and catalase was strongly elevated in RA synovial fluid (SF) compared with control SF. Although these enzymes are present in SF, the activities are insufficient to protect against oxygen free radicals and H2O2. In contrast to transferrin, ferritin was increased in RA synovial fluid. Ceruloplasmin was also elevated. When rat liver microsomes were used as a target for oxygen free radicals, serum and SF were both protective. Gel filtration experiments showed that the fraction pattern in which there was maximal protective potential against lipid peroxidation corresponded closely to the level of ceruloplasmin. After removal of ceruloplasmin from serum or SF, about 70% of the protective capacity disappeared. It is concluded that ceruloplasmin is an important protector against oxygen free radicals.
 ...
PMID:Protective factors against oxygen free radicals and hydrogen peroxide in rheumatoid arthritis synovial fluid. 674 61

Among various human tissues liver had the highest content of both CuZn superoxide dismutase and Mn superoxide dismutase. There were comparatively small differences in CuZn superoxide dismutase among other organs. The Mn superoxide dismutase contents were roughly half as large as the CuZn superoxide dismutase contents. The total amount of CuZn superoxide dismutase in the body was estimated to be 3900 mg. The superoxide dismutase activities of serum and cerebrospinal fluid corresponded to between 0.2-0.3 mg CuZn superoxide dismutase per liter. CuZn superoxide dismutase was apparently the source of the superoxide dismutase activity in cerebrospinal fluid, whereas this enzyme only accounted for about 15% of the serum activity. The superoxide dismutase activities of ceruloplasmin, transferrin and ferritin were very low, 40 000, 350 000 and 330 000 times lower than that of human CuZn superoxide dismutase. These factors contributed very little to serum superoxide dismutase activity. The activity of lymph was more than twice that of serum. Sera from patients with severely impaired renal function or bilaterally nephrectomized had a very high superoxide dismutase activity.
 ...
PMID:Distribution of CuZn superoxide dismutase and Mn superoxide dismutase in human tissues and extracellular fluids. 693 5

Antigens A and B, shown to be associated with the progestagen-dominated human endometrium, were partly purified and their properties studied. The antigens were recovered in the crude nuclei, the heavy particulate fraction and cytosol of decidua-rich tissue from early pregnancy. The antigens in cytosol were enriched by a combination of Concanavalin A-Sepharose chromatography and polyacrylamide gel electrophoresis. The immunological reactivity of the antigens after partial purification by Concanavalin A-Sepharose chromatography was retained after 30 min exposure to 4-85 degrees C at pH 7.4, or after 2 h to pH 2-12 at 22 degrees C. Trypsin, but not pepsin, RNase, DNase or neuraminidase, completely destroyed immunological reactivity of both antigens. The apparent molecular weight of both antigens determined by filtration on Sephadex G100 was 48 000. The isoelectric point of both antigens was approximately 4.9. The antigens were not immunologically related to transferrin, ceruloplasmin, alpha-1-antitrypsin, ferritin, uteroglobin, alpha-fetoprotein, human chorionic gonadotrophin, pregnancy-associated plasma proteins or pregnancy zone protein. Furthermore, the antisera to Antigens A and B did not react with the decidual cytosol of pregnant baboons or of pseudopregnant rats.
 ...
PMID:Properties of the progestagen-dependent protein of the human endometrium. 743 Dec 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>