Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The ferroxidase II protein from human serum is large and structurally complex. It possesses protein-bound lipid and copper components which are essential for the maintenance of its catalytic activity. Treatment of ferroxidase II with 8 M urea, 6 M guanidine hydrochloride, or 6 M guanidine hydrochloride and alkylation does not result in the dissociation of the enzyme into subunits. However, treatment with sodium dodecyl sulfate results in the dissociation of ferroxidase II into two nonidentical subunits, designated S-I and S-II. S-I contains little phospholipid, cholesterol, or copper and has a molecular weight of 3.8-3.9 X 10(5). In contrast, S-II contains bound phospholipid, cholesterol, and copper and has a molecular weight of 2.2-2.4 X 10(5). The lipid compositon of S-II is identical with the native enzyme. Sodium dodecyl sulfate-free S-I exhibits no ferroxidase activity. Immediately following removal of sodium dodecyl sulfate, S-II exhibits ferroxidase activity but S-II rapidly loses its activity in the absence of S-I. The separated subunits spontaneously reassociate upon removal of the sodium dodecyl sulfate to yield a fully active enzyme which chemically appears identical with native ferroxidase II. Furthermore, the reconstituted enzyme is stable. Both native and reconstituted ferroxidase II may be stored at 4 degrees C for 6 weeks without any loss in activity. This suggests that S-II, the copper and lipid-containing subunit, is the catalytic subunit and that S-I is essential for the stabilization of the enzymic activity of S-II. These results provide insight into the molecular structure and chemical composition of ferroxidase II and suggest that the complete native structure of ferroxidase II is required for the maintenance of i-s functional integrity.
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PMID:Dissociation and reconstitution of human ferroxidase II. 1 23

A surface coat of host serum proteins was detected on virulent Treponema pallidum by sodium dodecyl sulfate-gel electrophoresis. The loosely associated serum proteins could be removed by repeated washings in a protein-free medium. Washed T. pallidum retained the ability to readsorb numerous host proteins from rabbit serum as well as iodinated rabbit or human albumin. In addition, various avidly associated host serum proteins including albumin, alpha(2)-macroglobulin, transferrin, ceruloplasmin, immunoglobulin G, immunoglobulin M, and C3 were identified on the outer envelope of washed treponemes by an immunoadsorbent technique with protein A-bearing staphylococcus. Hyaluronidase treatment did not remove the avidly associated host proteins from the surface of washed treponemes, whereas trypsin treatment resulted in decreased levels of agglutination. Electrophoretic patterns of trypsin-treated treponemes showed that treponemal proteins as well as adsorbed host proteins were released concurrently by protease digestion. Reacquisition studies involving alpha(2)-macroglobulin and transferrin suggested the presence of noncompetitive binding sites for serum proteins on the treponemal outer envelope. Finally, differences among the T. pallidum preparations from individual rabbits with respect to incorporation of [(35)S]methionine, extent of agglutination with antisera, and length of time required for removal of avidly associated host proteins by trypsin treatment indicated biological variability among the treponemal populations.
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PMID:Surface-associated host proteins on virulent Treponema pallidum. 9 74

It was found in experiments on male albino rats that hypophysectomy was accompanied by an increase of potassium (on account of its accumulation in the mitochondria, nuclei and the microsomes) and copper in the liver. At the same time there was an increase in this organ of tha activity of Mg-2+-Na-+-K-+-ATPase and Mg-+-ATPase, and also a rise of ceruloplasmin activity in the blood serum. STH and TTH restored the sodium content to the normal and increased potassium level in the liver of hypophysectomized rats. ACTH and STH increased copper content in the hepatic tissue and normalized the activity of ceruloplasmin in the blood. All the hormones used promoted normalization of ATP-ase activity.
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PMID:[The effect of STH, TTH and ACTH on several aspects of copper, sodium and potassium metabolism in the livers of hypophysectomized white rats]. 16 74

In maturity onset diabetes the blood levels of total blood keto acids in terms of pyruvic, serum citric, calcium are significantly higher than in normal adults, while there is a decrease in reduced-blood glutathione, serum zinc, potassium and sodium levels. There were no significant differences between diabetes and normal adults in the serum levels of copper, ceruloplasmin oxidase activity, iron and magnesium.
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PMID:Blood-reduced glutathione, pyruvic acid, citric acid, ceruloplasmin oxidase activity and certain mineral changes in diabetes mellitus before and after treatment. 68 21

In cases of juvenile diabetes, there were lower than normal levels of reduced glutathione, ceruloplasmin oxidase activity, zinc, copper and sodium, while the other elements show no significant changes. The lower level of serum zinc, copper and sodium may be due to the osmotic diuresis and consequent polyurea of diabetes.
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PMID:Blood-reduced glutathione, serum ceruloplasmin and mineral changes in juvenile diabetes. 68 22

Partially purified ceruloplasmin mRNA was isolated using indirect immunoprecipitation of rat liver polysomes and poly(U)-Sepharose chromatography of polysomal RNA. This RNA programmed the synthesis of ceruloplasmin polypeptides in a cell-free system from mitochondria. Immunochemical analysis of the translation products revealed a 40-fold enrichment of the ceruloplasmin mRNA activity. The purified ceruloplasmin mRNA migrated as a major homogeneous component with an apparent molecular weight about 1 X 10(6) daltons in polyacrylamide gels containing sodium dodecyl sulfate. The immunoprecipitated products of the cell-free translation had molecular weights in the range 4.5--5.4 X 10(4) daltons as estimated by gel-electrophoresis under denaturating conditions. These values approach the weight of the half-molecule of native ceruloplasmin.
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PMID:Isolation and partial purification of ceruloplasmin messenger RNA from rat liver. 87 Aug 19

Soluble copper (Cu) preparations are both acute/chronic irritants and effective anti-inflammatory agents in rats. Copper is a prevalent component in several folk remedies for arthritis. Patients with rheumatoid arthritis and ankylosing spondylitis are reported to have higher-than-normal levels of serum copper, mainly associated with albumin. The anti-arthritis drug, D-penicillamine (Pn), efficiently strips Cu from some of its (pharmacologically inert) storage forms, e.g. Cu-albumin, Cu-polynucleotides yielding low M.W. Cu-Pn complexes, which show anti-inflammatory activity (ca. 5 X phenylbutazone) in rats irritated with carrageenan, oleyl alcohol, sodium urate and adjuvants. Under certain conditions Pn also blocks the amine-oxidase activity of caeruloplasmin, a circulating copper protein which is elevated in inflamed animals (an 'acute phase reactant'). Drugs, nutritional factors and the disease process may all possibly affect the movement of copper in vivo between inert reversible pharmacoactive reversible toxic forms.
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PMID:Ambivalent role of copper in inflammatory disorders. 94 95

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

We developed a direct, simple, and sensitive procedure for the simultaneous colorimetric assay of iron and copper in serum, using sodium dodecyl sulfate-ascorbic acid to dissociate iron and copper from transferrin and ceruloplasmin, respectively. We also use a new water-soluble reagent, 2-(5-nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol disodium salt (nitro-PAPS) and thioglycolic acid to eliminate interference from copper in the measurement of iron. Within- and between-run precisions of the present method were 2.5-2.8% for iron and 1.8-4.6% for copper. The proposed method is susceptible to interference by hemoglobin and lipemia, especially for the iron assay. Linear-regression analyses of results of the proposed method with those of the bathophenanthroline method for iron and of the atomic absorption spectroscopic method for copper correlated well (r = 0.996, Sy/x = 0.73 and r = 0.959, Sy/x = 1.11, respectively).
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PMID:Sensitive, direct procedures for simultaneous determinations of iron and copper in serum, with use of 2-(5-nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol (nitro-PAPS) as ligand. 162 8

Cu,Zn-superoxide dismutase activity, expressed on the basis of cell number, increased by 50% during sodium butyrate-induced differentiation of human K562 erythroleukemia cells. The increased enzyme activity was found to be concomitant with constant Cu,Zn-superoxide dismutase mRNA and immunoreactive protein levels and was accompanied by a rise in intracellular copper and glutathione. Incubation of K562 cell homogenates with copper caused an increase of Cu,Zn-superoxide dismutase activity which reached the levels observed after differentiation in the presence of sodium butyrate. The same treatment led to no significant activity increase in homogenates derived from differentiated cells. Externally added ceruloplasmin increased both intracellular copper levels and Cu,Zn-superoxide dismutase activity in undifferentiated cells to a level comparable with that observed after induction of differentiation. Both increments were abolished by depletion of cell glutathione. Cu,Zn-superoxide dismutase purified from control cells had both a lower kcat and a lower copper content than the enzyme purified from differentiated cells. From these data we conclude that: 1) Cu,Zn-superoxide dismutase is present in K562 cells also under the form of a less active copper-deficient enzyme, 2) the extent of enzyme activation is regulated post-translationally by differential delivery of copper as a function of differentiation stage, and 3) glutathione is likely to play a role in delivering copper to the copper-deficient protein in intact K562 cells.
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PMID:Increase of Cu,Zn-superoxide dismutase activity during differentiation of human K562 cells involves activation by copper of a constantly expressed copper-deficient protein. 176 55


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