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)

Ceruloplasmin (ferroxidase) the blue Cu-protein of vertebrate plasma, possesses significant oxidase activity towards Fe(II) and numerous aromatic amines and phenols. Its ferroxidase activity has led to the discovery that it is a molecular link between copper and iron metabolism. Ceruloplasmin mobilizes iron into the plasma from iron storage cells in the liver. An additional role of Cp may be as a contributor to the regulation of the balance of biogenic amines through its oxidase action on the epinephrine and the hydroxyindole series. Ceruloplasmin also serves as a major copper transport vehicle, comparable to transferrin for iron. Evidence is presented that the copper atoms of Cp are a prerequisite for copper utilization in the biosynthesis of cytochrome oxidase. The ability of Cp to release copper at specific cellular sites is believed to be related to its broad substrate spectrum of biological reducing agents. Thus Cp is a serum protein with several important functions, all of which are directly related to its oxidase activity.
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PMID:The biological role of ceruloplasmin and its oxidase activity. 18 81

Electron spin-echo decay envelopes for types I and II copper of Rhus vernicifera laccase and for type II copper of procine ceruloplasmin have been studied. Nuclear modulation patterns show that imidazole is a ligand for all of them. The linear electric field effect (LEFE) in EPR was studied for type I copper in a laccase preparation from which type II had been removed. The symmetry of the site is near tetrahedral and the magnitude of the LEFE is correlated with the intensity of blue color.
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PMID:Pulsed electron paramagnetic resonance studies of types I and II coper of Rhus vernicifera laccase and porcine ceruloplasmin. 19 89

The cytochrome oxidase activity of circulating leucocytes was investigated by means of a semiquantitative method using blood films. A significant decrease in activity was found in male rats, cattle and sheep that had been deprived of copper. During copper depletion, leucocyte cytochrome oxidase activity declined more slowly than did plasma copper concentration and plasma ferroxidase I activity, and so was less sensitive as a guide to the copper status of the animal.
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PMID:Changes in leucocyte cytochrome oxidase activity associated with deficiency of copper in laboratory and farm animals. 20 32

The low temperature (77 K) irradiation of oxidized ceruloplasmin and Rhus vernicifera laccase at the 330 nm absorption which arises from type 3 copper leads to the reduction of type 1 copper as demonstrated by bleaching of the 610 nm chromophore and the decrease of the EPR signal associated with this species. Type 2 copper remains unaffected. Concomitant with the type 1 copper reduction, a new EPR signal which is possibly that of a biradical appears. Upon thawing, type 1 copper is reversibly oxidized and the radical signal disappears. Irradiation of oxidized protein at the absorption band of type 1 copper produces no spectral change. An EPR study at room temperature confirms the wave-length specificity and reversibility of the photoreduction of type 1 copper and radical formation. Radical appearance and disappearance at room temperature are extremely slow (tau1/2 approximately 30 min). Optical studies at room temperature show that upon anaerobic irradiation of laccase in the 330 nm absorption band, both type 3 and type 1 chromophores are slowly reduced. Upon return to the dark and in the presence of O2, both type 3 and type 1 centers are reoxidized. Oxidizing equivalents either from O2 or K3Fe(CN)6 are required for the reoxidation reaction. These studies demonstrate that there is a direct energy transfer between type 3 and type 1 copper sites in blue copper oxidases.
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PMID:Photoreduction of copper chromophores in blue oxidases. 21 33

The electron paramagnetic resonance (EPR) spectra of the blue copper oxidase ceruloplasmin [ferroxidase, iron (II):oxygen oxidoreductase, EC 1.16.3.1] and of a derivative having the type I (blue) copper centers reversibly bleached are reported. The EPR spectrum of bleached ceruloplasmin has a seven-line superhyperfine structure in the g : formula: (see text) region that is attributed to the presence of three nitrogen-donor type 2 copper ligands. The EPR data suggest further that the type 2 copper in ceruloplasmin possesses a tetragonal coordination gometry. In the presence of varying amounts of fluoride, superhyperfine splitting patterns in the g : formula: (see text) region of both ceruloplasmin derivatives indicate that a maximum of two fluorides may be bound to the type 2 copper.
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PMID:Coordination environment and fluoride binding of type 2 copper in the blue copper oxidase ceruloplasmin. 21 31

1. Recent magnetic susceptibility measurements on laccase (monophenol,dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) from the lacquer tree Rhus vernicifera showed a deviation from Curie behaviour above 50 K, which was taken as evidence for an antiferromagnetically coupled Cu(II)-Cu(II) pair in the oxidized enzyme. The magnetic susceptibility of this protein has been reinvestigated. Further measurements on laccase from the fungus Polyporus versicolor and human ceruloplasmin (iron(II):oxygen oxidoreductase, EC 1.16.3.1) are presented. 2. The magnetic susceptibility of fungal laccase and lacquer tree laccase can be accounted for by the EPR detectable copper ions in the temperature range 40--300 K. 3. If an antiferromagnetically coupled Cu(II)-Cu(II) pair exists in the laccases, then the coupling, expressed as --J, should be at least of the order of 300 cm-1, as deduced from the Curie dependence of the susceptibility and the sensitivity in our measurements. 4. If an analogy with the laccases is assumed for the EPR invisible copper in ceruloplasmin then a limiting value of the coupling may be deduced also in this case, with --J at least of the order of 200 cm-1.
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PMID:Magnetic susceptibility of laccases and ceruloplasmin. 21 24

The methodology of blood sample preparation and analysis has been examined to further evaluate the technique of electron spin resonance (ESR) for possible use in detecting cancer and in monitoring the progress of cancer therapy. Frozen whole blood and serum samples from 278 normal donors and 97 cancer patients were studied by ESR for signal intensity from Cu+2 bound to ceruloplasmin (g factor = 2.05). The signal from this species (Cu+2-CP) in serum rose sharply during the first two hours of storage at room temperature after being drawn from the subject, and then reached a plateau. The average Cu+2-CP ESR signal intensity was significantly different for control groups of males, females not taking estrogen medication, and females taking estrogens. The mean ESR signal intensities of Cu+2-CP from cancer patients separated into the same groups as the control data were approximately twice as great as the mean control levels. Total serum copper levels were correlated with ESR intensities of Cu+2-CP and indicated that the ratio of Cu+2/Cu+1 in CP is higher in serum from cancer patients than from controls.
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PMID:Electron spin resonance studies on properties of ceruloplasmin and transferrin in blood from normal human subjects and cancer patients. 22 23

The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceruloplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spectroscopy. The spectra obtained are identical to the one obtained with leukemic blood. The consequences of this for the molecular events occurring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as reconsile the two existing and seemingly contradictory hypothesis. Possible implications for lipid peroxidation and for the respiratory process are discussed.
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PMID:On the possible involvement of ascorbic acid and copper proteins in leukemia. IV. ESR investigations on the interaction between ascorbic acid and some copper proteins. 22 87

Amino acid sequences of 8 plastocyanins, 8 azurins, stellacyanin, two regions in human ceruloplasmin (ferroxidase)--all of which proteins are known to bind a blue (type 1) copper--and subunit II of bovine mitochondrial cytochrome c oxidase were compared by statistical methods to assess similarities and derive possible evolutionary relationships. It is suggested that all of the examined proteins are monophyletic. The two ceruloplasmin partial sequences clearly demonstrate that this protein has undergone a duplication. A calculated most parcimonious phylogenetic tree shows the divergence of the azurin and plastocyanin ancestor to be the earliest event. Stellacyanin and later the blue oxidase (ceruloplasmin) evolved from the plastocyanin branch, which the cytochrome c oxidase subunit evolved from the azurin ancestor.
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PMID:On the evolution of blue proteins. 22 16

Ceruloplasmin, the blue copper-protein of the blood plasma, is believed by some workers to be involved in the metabolic management of 5-hydroxytryptamine (serotonin) during pregnancy. 5-Hydroxytryptamine is abortifacient in experimental animals. By some authors, a role has been suggested for it in human abortion. The plasma concentrations of 5-hydroxytryptamine, copper and ceruloplasmin were measured in non-pregnant women, in normal early pregnancy and in cases of spontaneous abortion. Compared with normal early pregnancy, cases of inevitable abortion show lower values for both plasma copper and ceruloplasmin and higher values for plasma 5-hydroxytryptamine. The possible implications of these findings are discussed in view of the alterations in ceruloplasmin values in pregnancy and in the light of what is known of the pharmacology and metabolism of 5-hydroxytryptamine. It it believed that these alterations in plasma copper, ceruloplasmin and 5-hydroxytryptamine in cases of inevitable abortion are the effect, rather than the cause, of abortion.
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PMID:5-Hydroxytryptamine (serotonin), copper and ceruloplasmin plasma concentrations in spontaneous abortion. 26 87


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