Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.16.3.1 (ceruloplasmin)
 5,074 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum changes of Ferroxidase I and II well as the total iron binding capacity (TIBC) and unsaturated iron binding capacity (UIBC) were measured throughout their gestation in 32 normal pregnant women. Significantly higher concentrations for all the above mentioned parameters were found as pregnancy advanced. Moreover, a significant and positive correlation between the weeks of gestation and a) serum Ferroxidase I (r:0.568 p < 0.001), d) serum Ferroxidase II (r:0.619 p < 0.001), c) serum TIBC (r:0.549 p < 0.01), and d) serum UIBC (r:0.424 p < 0.05) was found. The parallel serum changes of both ferroxidase with those of TIBC and UIBC are also shown in this study. The correlation of Ferroxidase I with TIBC (r:0.734 p < 0.001) and UIBC (r:0.536 p < 0.01) as that of Ferroxidase II with TIBC(r:0.634 p < 0.001) and UIBC (r:0.513 p < 0.01) was significant and positive. In conclusion, serum Ferroxidase I and II are progressively increased with serum TIBC and UIBC as pregnancy advances.
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PMID:Serum changes of Ferroxidases and iron-binding capacity in pregnancy. 833 Apr 35

Increased free-radical production leading to oxidative stress may contribute to the development of cardiovascular complications in haemodialysis patients. The ferroxidase activity of caeruloplasmin forms an important component of antioxidant defences in body fluids. The aim of this study was to assess ferroxidase activity in haemodialysis patients. Venous blood was collected from 83 haemodialysis patients immediately prior to and after dialysis and from 52 healthy controls. Immunoreactive caeruloplasmin was measured by rate nephelometry, and ferroxidase activity determined by measuring loading of ferrous iron onto iron-free transferrin. A significant reduction in ferroxidase activity was observed in dialysis patients when compared with controls (37 +/- 1.20 and 46 +/- 1.14 mU/l, respectively; p < 0.001). Following dialysis, ferroxidase activity rose significantly to 41 +/- 1.16 mU/l, with a significant difference still remaining between control and patient ferroxidase activity (p < 0.005). Immunoreactive caeruloplasmin was found to be similar in all groups (before dialysis 0.40 +/- 0.07 g/l, after dialysis 0.39 +/- 0.07 g/l, control 0.42 +/- 0.09 g/l: p = NS). A significant difference in caeruloplasmin-specific activity was therefore observed between predialysis, postdialysis and control samples (97 +/- 2.31, 105 +/- 1.74 and 112 +/- 1.51 mU/g; p < 0.001, p < 0.01, respectively). Ferroxidase activity of caeruloplasmin is impaired in renal failure. Inhibition of caeruloplasmin ferroxidase activity in dialysis patients may contribute to increased oxidative stress in these patients.
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PMID:The ferroxidase activity of caeruloplasmin is reduced in haemodialysis patients. 1072 Aug 90

The present study identifies proteins modified by nitration in the plasma of patients with ongoing acute respiratory distress syndrome (ARDS). The proteins modified by nitration in ARDS were revealed by microsequencing and specific antibody detection to be ceruloplasmin, transferrin, alpha(1)-protease inhibitor, alpha(1)-antichymotrypsin, and beta-chain fibrinogen. Exposure to nitrating agents did not deter the chymotrypsin-inhibiting activity of alpha(1)-antichymotrypsin. However, the ferroxidase activity of ceruloplasmin and the elastase-inhibiting activity of alpha(1)-protease inhibitor were reduced to 50.3 +/- 1.6 and 60.3 +/- 5.3% of control after exposure to the nitrating agent. In contrast, the rate of interaction of fibrinogen with thrombin was increased to 193.4 +/- 8.5% of the control value after exposure of fibrinogen to nitration. Ferroxidase activity of ceruloplasmin and elastase-inhibiting activity of the alpha(1)-protease inhibitor in the ARDS patients were significantly reduced (by 81 and 44%, respectively), whereas alpha(1)-antichymotrypsin activity was not significantly altered. Posttranslational modifications of plasma proteins mediated by nitrating agents may offer a biochemical explanation for the reported diminished ferroxidase activity, elevated levels of elastase, and fibrin deposits detected in patients with ongoing ARDS.
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PMID:Plasma proteins modified by tyrosine nitration in acute respiratory distress syndrome. 1078 26

In the neonatal period, there is a high iron load, while both the level and molar oxidase activity of ceruloplasmin are low. On the other hand, the neonatal xanthine oxidase (XO) activity is higher than later in life and XO has a significant iron-oxidizing capacity. We therefore studied the physiological contribution of XO to the ferroxidase activity of the plasma in 20 full-term newborn infants. Ferroxidase activity was measured spectrophotometrically, with Fe++ as substrate. The uric acid formed by XO was assayed by means of HPLC, with electrochemical detection. The total ferroxidase activity in the plasma was about one-fourth of the adult level and rapidly increased doubling within 3 days after birth. About 90% of the plasma ferroxidase activity was due to ceruloplasmin, the remainder being accounted for by ferroxidase II. The XO activity underwent a 30% (statistically non-significant) elevation at 24 h, though ferroxidase activity attributable to XO was not detected at any time. Accordingly, XO does not seem to add substantially to the total iron-oxidizing capacity of the plasma in the neonatal period. The high molar ferroxidase activity is probably of importance at the endothelial cell surface.
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PMID:Ferroxidases and xanthine oxidase in plasma of healthy newborn infants. 1176 13

Ferritin is an intracellular protein involved in iron metabolism. A cDNA PwYF-1 cloned from the adult Paragonimus westermani cDNA library encoded a putative polypeptide of 216 amino acids homologous with ferritins of vertebrates and invertebrates. Febinding motifs identified in PwYF-1 polypeptide were conserved and predicted to form a ferroxidase center. PwYF-1 polypeptide contained an extended peptide of 45 amino acids at its C-terminus. Recombinant PwYF-1 protein, expressed and purified from Escherichia coli, showed iron-uptake ability and ferroxidase activity. Ferroxidase activity of recombinant PwYF-1 protein was reactivated by secondary addition of apotransferrin to assay mixture. Mouse immune serum raised against the recombinant PwYF-1 protein recognized specifically 24 kDa protein from adult P. westermani lysate. PwYF-1 protein was localized to vitelline follicles and the eggs of P. westermani. Collectively, PwYF-1 protein was identified as a P. westermani yolk ferritin.
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PMID:Paragonimus westermani: molecular cloning, expression, and characterization of a recombinant yolk ferritin. 1285 17

The reticuloendothelial system has a central role in erythropoiesis and iron homeostasis. An important function of reticuloendothelial macrophages is phagocytosis of senescent red blood cells. The iron liberated from heme is recycled for delivery to erythrocyte precursors for a new round of hemoglobin synthesis. The molecular mechanism by which recycled iron is released from macrophages remains unresolved. We have investigated the mechanism of macrophage iron efflux, focusing on the role of ceruloplasmin (Cp), a copper protein with a potent ferroxidase activity that converts Fe2+ to Fe3+ in the presence of molecular oxygen. As shown by others, Cp markedly increased iron binding to apotransferrin at acidic pH; however, the physiological significance of this finding is uncertain because little stimulation was observed at neutral pH. Introduction of a hypoxic atmosphere resulted in marked Cp-stimulated binding of iron to apotransferrin at physiological pH. The role of Cp in cellular iron release was examined in U937 monocytic cells induced to differentiate to the macrophage lineage. Cp added at its normal plasma concentration increased the rate of 55Fe release from U937 cells by about 250%. The stimulation was absolutely dependent on the presence of apotransferrin and hypoxia. Cp-stimulated iron release was confirmed in mouse peritoneal macrophages. Stimulation of iron release required an intracellular "labile iron pool" that was rapidly depleted in the presence of Cp and apotransferrin. Ferroxidase-mediated loading of iron into apotransferrin was critical for iron release because ferroxidase-deficient Cp was inactive and because holotransferrin could not substitute for apotransferrin. The extracellular iron concentration was critical as shown by inhibition of iron release by exogenous free iron, and marked enhancement of release by an iron chelator. Together these data show that Cp stimulates iron release from macrophages under hypoxic conditions by a ferroxidase-dependent mechanism, possibly involving generation of a negative iron gradient.
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PMID:Role of ceruloplasmin in macrophage iron efflux during hypoxia. 1295 74

Ferroxidase activity was detected in a laccase-like multicopper oxidase (LMCO) produced in transgenic tobacco cells expressing an LMCO cDNA (Ltlacc2.2) cloned from yellow-poplar (Liriodendron tulipifera). This marks the first report of ferroxidase activity associated with a plant laccase and suggests that some members of this plant enzyme family may have physiological functions based on activities other than their more widely recognized phenoloxidase activity. Recent work with LMCOs from bacteria, yeast and mammals has shown that metal oxidase activities in these enzymes can be important for their primary physiological functions, With respect to ferroxidase activity in certain plant LMCOs, it is proposed that the high levels of LMCO expression in plant vascular tissues may reflect the need for high-efficiency iron uptake pumps in tissues that undergo lignification during normal development. Such iron uptake pumps would function to minimize levels of free iron so that reactive oxygen species do not reach toxic levels when H2O2 is generated for peroxidase-mediated monolignol coupling during lignin deposition.
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PMID:Ferroxidase activity in a laccase-like multicopper oxidase from Liriodendron tulipifera. 1506 Oct 81

Ferroxidase (encoded by the mco gene), a component of a ferrous iron uptake pathway in Pseudomonas aeruginosa, was detected in all of the 35 respiratory clinical isolates surveyed; in contrast, considerable variation in siderophore expression was observed. The ubiquitous expression of this periplasmic ferroxidase suggests that it plays a key role in iron uptake in this opportunistic pathogen.
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PMID:Survey of ferroxidase expression and siderophore production in clinical isolates of Pseudomonas aeruginosa. 1518 77

As ceruloplasmin and copper abnormalities have been implicated in schizophrenia, we investigated the role of a second copper-containing non-ceruloplasmin protein, the iron oxidase ferroxidase II, in a prospective study of ten inpatients with schizophrenia and a comparison group. Ferroxidase II is a protein known to reciprocally regulate with ceruloplasmin in Wilson's disease, an illness characterized by psychotic symptoms, decreased ceruloplasmin, and increased copper deposition in tissues. Ferroxidase II plays a key role in the maintenance of near-normal iron metabolism in Wilson's disease, but its role in schizophrenia has never been studied. In this study, we assayed ceruloplasmin by two enzymatic assays, a standard clinical laboratory p-phenylenediamine oxidation assay and a second assay based on the rate of the oxidation and incorporation of iron (Fe3+) into transferrin; we assayed ferroxidase II activity using this second iron oxidation assay. We found that ceruloplasmin levels as measured by both enzymatic methods, but not ferroxidase II, were elevated in schizophrenia. The increased ceruloplasmin also correlated with elevated serum copper as assayed by atomic absorption spectrophotometry, which was unsurprising as the majority of copper in blood is bound to ceruloplasmin. It has been proposed that copper, as a component of several enzymes linked to dopamine synthesis, may play a role in schizophrenia by exacerbating or perpetuating dopaminergic dysregulation. Our study suggests that the ceruloplasmin elevation in schizophrenia is specific, and not simply an elevation of plasma copper-containing oxidative enzymes. Increases in ceruloplasmin may result in increased levels of copper, which ultimately proves deleterious in schizophrenia.
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PMID:Plasma copper, iron, ceruloplasmin and ferroxidase activity in schizophrenia. 1684 75

The effect of human lactoferrin on the arrest of experimental hemorrhagic anemia consequences was studied in rats. After six blood losses (days 1-4 and 7-8 of the experiment), the rats developed acute anemia: hemoglobin concentration decreased to 59% of the initial level, serum iron level decreased 3-fold. Intraperitoneal injections of lactoferrin (10 mg/day) for 4 days starting from day 7 led to an increase in hemoglobin level to 109% and of serum iron to 125% on day 14. In controls, hemoglobin level on day 14 was 70% and iron content 49% of the initial level. Ferroxidase activity of ceruloplasmin in blood serum decreased after 5 blood losses returned to normal only in rats receiving lactoferrin. The results indicate that lactoferrin modified ceruloplasmin activity in vivo, promoting normalization of iron metabolism.
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PMID:Effect of lactoferrin on consequences of acute experimental hemorrhagic anemia in rats. 2111 95


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