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 copper binding tripeptide, glycyl-L-histidyl-L-lysine [GHK:Cu(II)] has a plethora of biological effects related to the wound healing process. The presence of iron complexes in damaged tissues is detrimental to wound healing, due to local inflammation, as well as microbial infection mediated by iron. To test if the wound healing properties of GHK:Cu(II) are due to an affect on iron metabolism, we examined the effects of GHK:Cu(II) on iron catalyzed lipid peroxidation. GHK:Cu(II) inhibited lipid peroxidation only if the iron source was ferritin. Whereas GHK:Cu(II) inhibited ferritin iron release it did not exhibit significant superoxide dismutase-like or ceruloplasmin-like activity. We propose that GHK:Cu(II) binds to the channels of ferritin involved in iron release and physically prevents the release of Fe(II). Thus, a biological effect of GHK:Cu(II), possibly related to wound healing, may be the inhibition of ferritin iron release in damaged tissues, preventing inflammation and microbial infections.
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PMID:Effects of glycyl-histidyl-lysyl chelated Cu(II) on ferritin dependent lipid peroxidation. 224 43

In unseparated human blood the reactivity of yeast copper (I)-thionein on TPA-activated polymorphonuclear leukocytes was evaluated and compared with low Mr copper chelates exerting Cu2Zn2 superoxide dismutase mimetic activity. Cu, 18 microM, in the form of Cu-thionein was sufficient to inhibit the superoxide production of activated human blood phagocytes by 50%. Furthermore, the scavenging of hydroxyl radicals and singlet oxygen by Cu(I)-thionein was determined, using the 2-deoxyribose fragmentation assay induced by decaying K3CrO8 and the NADPH oxidation caused by UVA illuminated psoralen, respectively. The inhibitory reactivity of Cu-thionein in both assays was compared with that of serum proteins including albumin, ceruloplasmin, transferrin, and ferritin. The galactosamine/endotoxin-induced hepatitis in male NMRI mice was used to evaluate the antiinflammatory reactivity of Cu-thionein in vivo. The serum copper, superoxide dismutase, and sorbitol dehydrogenase concentrations, as well as the activity of polymorphonuclear leukocytes in unseparated blood seemed most appropriate to quantify the protective capacity of Cu-thionein in the course of an oxidative stress-dependent liver injury. The intraperitoneal application of 32.5 mumols/kg thionein-Cu limited this damage to 45%.
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PMID:Antiinflammatory reactivity of copper(I)-thionein. 224 84

Three recombinant human apoferritin variants were added to ferrous iron and the amount of lipid peroxidation produced by hydrogen peroxide was studied. The H-apoferritin had the strongest inhibitory effect on lipid peroxidation, probably due to its ferroxidase activity. The L-apoferritin inhibited lipid peroxidation slowly and only at neutral pH. The H-mutant 91, deleted of the last 22 C-terminal amino acids, and which is not able to form an iron core, had minimal effects on iron lipid peroxidation. It was concluded that both ferro-oxidase and iron mineralization activities are necessary for ferritin iron detoxifying action.
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PMID:Iron detoxifying activity of ferritin. Effects of H and L human apoferritins on lipid peroxidation in vitro. 226 41

Pea seed ferritin is able to incorporate ferrous iron into the mineral core. Fe2+ may be formed by reduction of exogenous Fe3+ with ascorbate or by photoreduction by ferritin and by ferric citrate. In our experimental conditions the bulk of the photoreduction is carried out by ferritin, which is able to photoreduce its endogenous iron. Citrate does not enhance the photoreduction capacity of ferritin, and exogenous ferric citrate improves the yield of the reaction by about 30%. The mineral core of the ferritin is shown to photoreduce actively, and the protein shell does not participate directly in the photoreduction. Low light intensities and low concentration of reducing agents do not allow a release of iron from ferritins, but induce a 'redox mill' of photoreduction and simultaneous ferroxidase-mediated incorporation. High ascorbate concentrations induce the release of ferritin iron. These reactions are accompanied by the correlated occurrence of damage caused by radicals arising from Fenton reactions, leading to specific cleavages in the 28 kDa phytoferritin subunit. This damage caused by radicals occurs during the oxidative incorporation into the mineral core and is prevented by o-phenanthroline or by keeping the samples in the dark.
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PMID:Photoreduction and incorporation of iron into ferritins. 237 59

Eleven potential biochemical markers were measured in serum from 33 patients with malignant and 13 with benign colorectal disease: four isoenzymes (creatine kinase-BB, homoarginine-sensitive alkaline phosphatase, salivary-type amylase, and macro-creatine kinase type 2), five specific proteins (ferritin, alpha 1-acid glycoprotein, C-reactive protein, alpha 1-antitrypsin, and ceruloplasmin), one oncofetal antigen (carcinoembryonic antigen, CEA), and one hormone (beta human choriogonadotropin). The sensitivity of individual markers for the detection of early-stage malignancy (n = 11) ranged from 0% to 64% (CEA 18%); for late-stage colon malignancy (n = 12) from 8% to 83% (CEA 83%). Specificity in patients (n = 10) with benign intestinal disease ranged from 80% to 100% (CEA 100%). The five most-sensitive markers--C-reactive protein, alpha 1-glycoprotein, CEA, macrocreatine kinase type 2, and homoarginine-sensitive alkaline phosphatase--were selected for use as a "colon panel." In retrospective comparison, use of the colon panel instead of CEA alone increased sensitivity by 17% and 64% for late-and early-stage cancer, respectively; specificity, however, decreased by 30%, but should improve with serial testing.
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PMID:Multiple markers of malignancy in sera of patients with colorectal carcinoma: preliminary clinical studies. 241 37

Two-wk-old broiler chicks were inoculated via crop intubation with Eimeria acervulina at two doses: 10(5) or 10(6) sporulated oocysts/bird or with Eimeria tenella at a dose of 10(5) sporulated oocysts/bird. Serum and liver samples were collected on days 3 and 6 post-inoculation (PI). There were no significant changes in serum or liver zinc, copper, and iron concentrations in any of the infected groups by 3 d PI. However, on d 6, PI serum protein was significantly reduced in all of the infected groups compared to their pair-fed controls. The chicks infected with E. tenella had significantly reduced serum zinc (1.20 vs 1.77 micrograms/mL) and iron (0.44 vs 1.28 micrograms/mL) concentrations and significantly elevated serum copper (0.28 vs 0.17 micrograms/mL) and ceruloplasmin levels (20.33 vs 11.11 micrograms/mL) compared to their pair-fed counterparts. Those chicks infected with E. acervulina (10(6) oocysts/bird) exhibited significantly reduced serum iron concentration by 6 days PI (0.90 vs 1.14 micrograms/mL). Liver zinc was significantly increased in the chicks infected with E. tenella (349 vs 113 micrograms/g dry liver wt), as was copper (24 vs 19 micrograms/g), whereas liver iron concentration was significantly reduced (172 vs 243 micrograms/g) compared to pair-fed controls. At both dose levels, the chicks infected with E. acervulina exhibited a significant reduction in liver iron by 6 d PI. Hepatic cytosol metals generally reflected whole tissue levels. Metallothionein (MT)-bound zinc was significantly elevated in the chicks infected with E. tenella. Iron bound to a high molecular weight, heat-stable protein fraction (presumably cytoplasmic ferritin) was significantly reduced in chicks infected with E. acervulina, as well as those infected with E. tenella. Collectively, the changes in serum zinc, copper, and iron concentrations, as well as the changes in hepatic zinc and MT-zinc concentrations in the chicks infected with E. tenella were similar to changes evoked during an acute phase response to infection. It is possible that a secondary bacterial infection or inflammation stemming from erosion of the lining of the cecum may play a role in the response of trace element metabolism to the E. tenella infection.
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PMID:Serum and liver zinc, copper, and iron in chicks infected with Eimeria acervulina or Eimeria tenella. 248 59

5-Hydroperoxymethyl-2'-deoxyuridine (HPMdU) is formed in DNA by ionizing radiation. Although relatively stable, HPMdU eventually decomposes to two products 5-hydroxymethyl-2'-deoxyuridine (HMdU) and 5-formyl-2'-deoxyuridine (FdU). We show that a number of transition metal ions and metalloproteins accelerate this process. Of the metal ions tested, Sn(II) and Fe(II) were the most active, with the former producing exclusively HMdU, and the latter, a mixture of both. Cu(I), Cu(II), Co(II), and Ni(II) induced a predominant generation of FdU, with copper ions being more effective than Co and Ni. FdU was also preferentially formed in the presence of the iron-containing proteins transferrin and ferritin, whereas HMdU was the major product in the presence of apotransferrin as well as in the presence of ceruloplasmin, a copper-containing protein.
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PMID:Decomposition of nucleoside hydroperoxide by metals and metalloproteins. 248 13

The diabetogenic action of alloxan is believed to involve oxygen free radicals and iron. Incubation of glutathione (GSH) and alloxan with rat liver ferritin resulted in release of ferrous iron as assayed by spectrophotometric detection of ferrous-bathophenanthroline complex formation. Neither GSH nor alloxan alone mediated iron release from ferritin. Superoxide dismutase (SOD) and catalase did not affect initial rates of iron release whereas ceruloplasmin was an effective inhibitor of iron release. The reaction of GSH with alloxan resulted in the formation of the alloxan radical which was detected by ESR spectroscopy and by following the increase in absorbance at 310nm. In both instances, the addition of ferritin resulted in diminished alloxan radical detection. Incubation of GSH, alloxan, and ferritin with phospholipid liposomes also resulted in lipid peroxidation. Lipid peroxidation did not occur in the absence of ferritin. The rates of lipid peroxidation were not affected by the addition of SOD or catalase, but were inhibited by ceruloplasmin. These results suggest that the alloxan radical releases iron from ferritin and indicates that ferritin iron may be involved in alloxan-promoted lipid peroxidation.
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PMID:Alloxan- and glutathione-dependent ferritin iron release and lipid peroxidation. 253 98

Total plasma iron turnover in man is about 36 mg/day. Transferrin is the iron transport protein of plasma, which can bind 2 atoms of iron per protein molecule, and which interacts with various cell types to provide them with the iron required for their metabolic and proliferative processes. All tissues contain transferrin receptors on their plasma membrane surfaces, which interact preferentially with diferric transferrin. In erythroid cells as well as certain laboratory cell lines, the removal of iron from transferrin apparently proceeds via the receptor-mediated endocytosis process. Transferrin and its receptor are recycled to the cell surface, whereas the iron remains in the cell. The mode of iron uptake in the hepatocyte, the main iron storage tissue, is less certain. The release of iron by hepatocytes, as well as by the reticuloendothelial cells, apparently proceeds nonspecifically. All tissues contain the iron storage protein ferritin, which stores iron in the ferric state, though iron must be in the ferrous state to enter and exit the ferritin molecule. Cellular cytosol also contains a small-molecular-weight ferrous iron pool, which may interact with protoporphyrin to form heme, and which apparently is the form of iron exported by hepatocytes and macrophages. In plasma, the ferrous iron is converted into the ferric form via the action of ceruloplasmin.
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PMID:Biochemistry of nonheme iron in man. I. Iron proteins and cellular iron metabolism. 266 99

The human ferritin L-chain cDNA was cloned into a vector for overproduction in Escherichia coli, under the regulation of a lambda promoter. The plasmid obtained contains the full L-chain coding region modified at the first two codons. It is able to direct the synthesis of the L-chain which can constitute up to 15% of the total soluble protein of bacterial extract. The L-chains assemble to form a ferritin homopolymer with electrophoretic mobility, molecular weight, thermal stability, spectroscopic, and immunological properties analogous to natural ferritin from human liver (95% L-chain). This recombinant L-ferritin is able to incorporate and retain iron in solution at physiological pH values. At variance with the H-ferritin, the L form does not uptake iron at acidic pH values and does not show detectable ferroxidase activity. It is concluded that ferritin L-chain lacks the ferroxidase site present in the H-chain and that the two chains may have specialized functions in intracellular iron metabolism.
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PMID:Expression and structural and functional properties of human ferritin L-chain from Escherichia coli. 266 70


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