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)

1. The curved plots of 1/v against 1/[S] obtained when caeruloplasmin oxidizes NN-dimethyl-p-phenylenediamine were investigated. The first free-radical oxidation product of caeruloplasmin oxidation of NN-dimethyl-p-phenylenediamine is required for curvature, as straight-line plots were obtained when activities were measured either before appreciable free-radical product had appeared or in the presence of ascorbate, which reduced it back to NN-dimethyl-p-phenylenediamine. 2. In the presence of ascorbate linear reciprocal-plots were obtained with all of the 37 substrates tested. V(max.) values varied over only an eightfold range and those for the 20 p-amino compounds over only a twofold range. K(m) values, however, varied over a 10(4)-fold range. The small range of V(max.) values indicates that the rate-limiting step in caeruloplasmin action is relatively independent of the nature of the substrate. K(m) values suggest that substrates bind primarily by ring electrons, although certain side-chain groups increased the K(m) in a manner unrelated to likely changes of ring-electron densities. A mechanism involving repulsion between negative charges on the substrate and the enzyme was supported by the variation of the K(m) of 5-hydroxyindol-3-ylacetic acid with pH.
Biochem J 1972 Sep
PMID:A method for obtaining linear reciprocal plots with caeruloplasmin and its application in a study of the kinetic parameters of caeruloplasmin substrates. 464 13

Serum levels, urinary excretion, and clearances of several proteins of different molecular weights were studied in 18 patients with mono- and myelomonocytic leukemia. Nine patients had normal renal function (group A) and nine had impaired renal function with azotemia (group B). The majority of patients in both groups had increased concentration of immunoglobulins, particularly IgG, IgA, and IgM; IgD level was normal. Serum transferrin and alpha(2)-macroglobulin were frequently reduced while the level of ceruloplasmin was often increased, especially in patients with azotemia. The activity of lysozyme in the serum was high in all patients, but was considerably higher in group B. Proteinuria was found in most patients but was more prominent in group B. Almost invariably albumin constituted less than 25% of the total protein excreted. Qualitative analysis of various urinary proteins by immunochemical techniques and clearance studies suggested the presence of glomerular as well as tubular dysfunction. Determination of urinary lysozyme frequently showed no direct correlation between the serum level of the enzyme and its concentration in the urine or its clearance by the kidney. In addition to glomerular filtration, impaired tubular reabsorption may account for the high level of lysozyme in the urine. It is postulated that the very high level of lysozyme in the glomerular filtrate and possibly hypergammaglobulinemia may play a role in the induction of tubular damage. Renal impairment has been correlated with histological changes in the kidneys. From a comparative study of various leukemias, it seems that the combined glomerular-tubular dysfunction is a manifestation unique to mono- and myelomonocytic leukemia.
J Clin Invest 1970 Sep
PMID:Serum and urinary proteins, lysozyme (muramidase), and renal dysfunction in mono- and myelomonocytic leukemia. 527 Sep 14

The way in which iron is handled by the duodenal mucosa, the reticuloendothelial system, the hepatic parenchymal cell, and the normoblast was investigated in copper-deficient swine.Copper-deficient swine failed to absorb dietary iron at the normal rate. Increased amounts of stainable iron were observed in fixed sections of duodenum from such animals. When (59)iron was administered orally, the mucosa of copper-deficient animals extracted iron from the duodenal lumen at the normal rate, but the subsequent transfer to plasma was impaired.When intramuscular iron supplements were given to copper-deficient pigs, increased amounts of iron were found in the reticuloendothelial system, the hepatic parenchymal cells, and in normoblasts (sideroblasts). Hypoferremia was observed in the early stages of copper deficiency, even though iron stores were normal or increased. When red cells that were damaged by prolonged storage were administered, the reticuloendothelial system failed to extract and transfer the erythrocyte iron to the plasma at the normal rate. Administration of copper to copper-deficient animals with normal iron stores resulted in a prompt increase in the plasma iron. The observed abnormalities in iron metabolism are best explained by an impaired ability of the duodenal mucosa, the reticuloendothelial system, and the hepatic parenchymal cell to release iron to the plasma. It is suggested that copper is essential to the normal release of iron from these tissues. This concept is compatible with the suggestion made by others that the transfer of iron from tissues to plasma requires the enzymatic oxidation of ferrous iron, and that the plasma copper protein, ceruloplasmin, is the enzyme (ferroxidase) which catalyzes the reaction. Because excessive amounts of iron were found in normoblasts, it is suggested that an additional defect in iron metabolism affects these cells and plays a major role in the development of anemia. As a result of the proposed defect, iron cannot be incorporated into hemoglobin and, instead, accumulates as nonhemoglobin iron.
J Clin Invest 1968 Sep
PMID:Iron metabolism in copper-deficient swine. 567 26

A marked increase in the serum copper and caeruloplasmin levels in 25 female subjects taking oral contraceptives is noted. The correlation between the copper and caeruloplasmin concentrations, together with the finding of normal urine copper levels in 10 of the subjects, suggests that the increased serum copper is due to increased caeruloplasmin synthesis.
J Clin Pathol 1966 Sep
PMID:Raised serum copper and caeruloplasmin levels in subjects taking oral contraceptives. 591 65

Decreased serum caeruloplasmin levels in patients with Wilson's disease have been attributed to decreased caeruloplasmin synthesis in the hepatocyte. An immunoperoxidase procedure was used to identify caeruloplasmin in liver biopsies. The pattern of staining in biopsies from patients with Wilson's disease did not differ from the pattern seen in normal adult or neonatal liver. This indicates that immunoreactive caeruloplasmin is synthesized by the liver cell in Wilson's disease. Low serum levels of caeruloplasmin may reflect an abnormality of copper incorporation into the apoprotein or an abnormality of holocaeruloplasmin export.
Liver 1982 Sep
PMID:Immunocytochemical identification of caeruloplasmin in hepatocytes of patients with Wilson's disease. 618 93

Hepatocellular blood plasma inclusions were demonstrated in conventional formalin-fixed paraffin-embedded liver tissue by the immunoperoxidase technique in 114 out of 197 liver specimens. They were usually round or elliptical in shape, their size varying from a few microns to about 30 microns in diameter. Albumin, fibrinogen, alpha 1-antitrypsin, IgG, IgM, IgA, ceruloplasmin and transferrin were demonstrated in the inclusions, in that order of frequency. A majority were negative with the periodic acid Schiff stain after amylase digestion, but a few were positive. Many of them seemed to correspond to vacuoles in the hepatocytes but some were not seen in HE-stained sections. The inclusions were frequently seen in autopsy liver specimens, but were rare in surgical ones. Most of the inclusions might develop at an agonal stage, probably as a result of hypoxia or circulatory disturbances in the livers.
Liver 1982 Sep
PMID:Cytoplasmic blood plasma inclusions in human hepatocytes. 618 94

A human hepatoma cell line, HuH-7, which was established from a hepatocellular carcinoma, was found to replicate continuously in a chemically defined medium when the medium was supplemented with Na2SeO3. The cells grew better in this medium than in serum-containing medium without any adaptation period. Other established human hepatoma and hepatoblastoma cell lines, HuH-6 cl-5, PLC/PRF/5, huH-1, and huH-4, also grew in the defined medium. Although HLEC-1 cells failed to proliferate continuously with Na2SeO3 alone, they grew if a cell-free conditioned medium from HuH-7 cells was added to the medium. These cell lines, except the HLEC-1 cell line, produced the following human plasma proteins among those examined: albumin, prealbumin, alpha 1-antitrypsin, ceruloplasmin, fibrinogen, fibronectin, haptoglobin, hemopexin, beta-lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, Complement Components 3 and 4, and alpha 1-fetoprotein. Beside plasma proteins, the media from HuH-7, HuH-6 cl-5, PLC/PRF/5, and huH-1 contained anti-carcinoembryonic antigen-reactive proteins, and those from PLC/PRF/5, huH-1, and huH-4 medium contained hepatitis B surface antigen. These proteins were detected during periods of serial cultivation over 9 months under the above culture conditions. The hepatoma cell lines grown in the fully defined synthetic medium may provide a new approach for investigating the growth and metabolism of human hepatoma cells in vitro.
Cancer Res 1982 Sep
PMID:Growth of human hepatoma cells lines with differentiated functions in chemically defined medium. 628 15

When leukocyte lysosomal extracts are used as a source of elastase and are combined with a fraction of plasma containing sufficient alpha 1-protease inhibitor (alpha 1-Pi) to inhibit all but 30 to 40% of the elastase amidase activity, elastolysis occurs at 69% of the rate of the uninhibited elastase controls (0.125 M NaCl; pH, 6.5). Proteolysis of elastin requires the presence of NaCl. At pH 8.6, elastolysis is decreased to 30 to 40% of free elastase controls by 1.0 M NaCl. At pH 6.5, on the other hand, elastolysis is increased to 83% of the control values by these higher NaCl concentrations. The activity of human leukocyte myeloperoxidase is optimal at pH 6 to 6.5 and at NaCl concentrations between 0.25 and 1.0 M. Purified myeloperoxidase, alpha 1-Pi, and elastase, in the presence of NaCl and hydrogen peroxide, can reproduce this phenomenon at pH 6.5, suggesting that the occurrence of elastolysis in lysosomal extract-plasma mixtures may in part be a result of the oxidative inactivation of alpha 1-Pi by myeloperoxidase present in the lysosomal extract. Human ceruloplasmin, the major antioxidant of plasma, inhibits this myeloperoxidase-dependent reaction, without interfering either with free elastase activity or with the appearance of activity in plasma-lysosomal extract mixtures at pH 8.6. The "antioxidant" activity of ceruloplasmin is inhibited by azide. These results suggest that antioxidants such as ceruloplasmin may be an important determinant of lung defense in persons chronically exposed to oxidants.
Am Rev Respir Dis 1982 Sep
PMID:Ceruloplasmin: plasma inhibitor of the oxidative inactivation of alpha 1-protease inhibitor. 628 6

We examined that growth-promoting activity of two different human albumin (HSA) preparations for human diploid fibroblasts in serum-free RITC 80-7 medium. The activity of one preparation (sample A) was affected markedly by environmental oxygen, whereas the other (sample B) was little affected. Sample B contained ceruloplasmin (Cp) and haptoglobin (Hp) as impurities. To detect the generation of superoxide anion in the media the amount of reduction of cytochrome c that is inhibited by superoxide dismutase (SOD) was determined. In an aerobic environment it was relatively large in comparison with reduction inhibited in a hypoxic environment. Reduction in the sample A with HSA-supplemented medium was relatively large in comparison with that in sample B with HSA-supplemented medium. The reduction of cytochrome c also was inhibited by Cp (25 mg/l) and catalase (4000 units/ml). Moreover, SOD, Cp, catalase and Hp.Hb (but not Hp) partially prevented oxygen-dependent reduction in growth in an aerobic environment when added to sample A HSA-supplemented medium. These results suggest that Cp and Hp.Hb act as an antioxidants in culture.
Cell Struct Funct 1983 Sep
PMID:Effects of ceruloplasmin and the haptoglobin-hemoglobin complex on the oxygen-dependent reduction in growth of human diploid fibroblasts in serum-free, albumin containing medium. 632 37

Methods were developed for the measurement of superoxide dismutase (SOD), diamine oxidase (DAO) and caeruloplasmin oxidase in the blood of thoroughbred horses. These enzymes were measured in 178 normal thoroughbreds stabled throughout the United Kingdom. The relationships between the activities of SOD, DAO and caeruloplasmin oxidase and the blood concentrations of their associated trace metals (copper, zinc and manganese) were studied in 52 of the thoroughbreds. Trace metals were measured by electrothermal atomic absorption spectrophotometry. No relationships were found between the activities of erythrocyte SOD and serum/whole blood copper, zinc and manganese, or serum DAO and serum copper or zinc concentrations. Caeruloplasmin oxidase in equine blood was found to be correlated to serum copper concentration, r = 0.695 (P less than 0.001) over the normal range. Samples from thoroughbreds with trace metal deficiency or toxicity were not available for study. The observed normal ranges for the activity of these enzymes are as follows: SOD: 50 to 200 units per ml whole blood between 5 and 95 percentiles; DAO: 0.1 to 28.5 units per litre (means = 14.8, SD 7.1) and caeruloplasmin oxidase; 11.6 to 35.8 units per ml (means = 23.7, SD 6.0). For numerical simplicity, the activity of DAO is given in units per litre, compared to units per ml for caeruloplasmin oxidase and SOD.
Res Vet Sci 1983 Sep
PMID:Measurement of superoxide dismutase, diamine oxidase and caeruloplasmin oxidase in the blood of thoroughbreds. 641 70


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