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)

Alpha 2-macroglobulin, caeruloplasmin and haptoglobin were measured in the sera of patients with necrobiosis lipoidica, granuloma annulare and diabetes. Alpha 2 Macroglobulin and caeruloplasmin were significantly raised in diabetes, and caeruloplasmin was raised in necrobiosis lipoidica without diabetes. The ratio of alpha 2-globulin to serum albumin was significantly high for all three proteins in diabetes, and for haptoglobin and caeruloplasmin in necrobiosis lipoidica. None of these proteins was abnormally raised in non-diabetic patients with granuloma annulare. There is good evidence that the plasma protein changes in diabetes contribute to the development of microangiopathy by their influence on blood viscosity. The altered plasma protein profile in necrobiosis lipoidica may therefore be of relevance to the development of the vascular lesions in this disorder.
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PMID:Serum alpha 2 globulin levels in granuloma annulare and necrobiosis lipoidica. 617 Mar 4

This study systematically examined the characteristics of specific binding of adult diferric transferrin to its receptor using a Triton X-100 solubilized preparation from human placentas as the receptor source. The following information was obtained. The ionic strength for maximal binding is in the range of 0.1-0.3 M NaCl. The pH optimum for specific binding extends over the range, from pH 6.0-10.0. Specific binding of diferric transferrin is not affected by 2.5 approximately 50 mM CaCl2 or by 10 mM EDTA. Triton X-100 in the concentration range of 0.02-3.0% does not affect specific binding. Specific binding is saturated within 10 min at 25 or 37 degrees C in the presence of excess amounts of diferric transferrin. The binding is reversible and the dissociation of diferric transferrin from the transferrin receptor is complete within 40 min at 25 degrees C. Apotransferrin, both adult and fetal, showed less binding than the holotransferrin species by competitive binding assay in the presence of 10 mM EDTA independent of up to 20 mM CaCl2. A 1500-fold molar excess of adult and fetal apotransferrin is required to give 40% inhibition for 125I-labeled diferric transferrin binding. Since calcium ion is not a factor, and since apotransferrin has such high binding affinity for iron (Ka = 1 X 10(24], this experiment suggests that the EDTA was necessary to prevent conversion of apotransferrin to holotransferrin from available iron in the reaction system. The specificity of the transferrin receptor for transferrin was examined by competitive binding studies in which 125I-diferric transferrin binding was measured in the presence of a series of other proteins. The proteins tested in the competitive binding studies were classified into three groups; in the first group were human serum albumin and ovalbumin; in the second group were proteins containing iron ions, such as hemoglobin, hemoglobin-haptoglobin complex, heme-hemopexin complex, ferritin, and diferric lactoferrin; in the third group were the metal-binding serum proteins, ceruloplasmin and metallothionein. None of these proteins except ferritin showed inhibition of diferric transferrin binding to the receptor. The effect of ferritin was small since a 700- to 1500-fold molar excess of ferritin is required for 50% inhibition of binding of diferric transferrin to the receptor.
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PMID:Characterization of transferrin binding and specificity of the placental transferrin receptor. 631 Nov 10

We have previously shown that chelated copper stimulates the release of luteinizing hormone-releasing hormone (LHRH) from isolated hypothalamic granules. In this study, we wished to ascertain if chelated copper acts on hypothalamic neurons to stimulate LHRH release and, if so, what is the ligand specificity of this interaction. An in vitro system of explants of the median eminence area (MEA) was established and characterized. MEA explants were exposed for 15 min to 50 microM copper, and then they were incubated for 75 min in copper-free medium. Copper led to a transient increase in the rate of LHRH release; the maximal rate was attained 15 min after transfer of the MEA to copper-free medium. In addition, we found that copper complexed to histidine (Cu-His), but not ionic copper, stimulated LHRH release, the magnitude of which was dependent on the dose of Cu-His. The chelator specificity for Cu complex action was such that Cu-His stimulated LHRH release 4.9-fold and Cu-Cys stimulated release 2.5-fold, whereas neither Cu-Thr, Cu-Gly-His-Lys, Cu-bovine serum albumin, nor ceruloplasmin stimulated LHRH release. Based on these results and those of others indicating that the concentration of copper in hypothalamic axonal terminals is 1-2 orders of magnitude greater than plasma, we propose that copper released in the vicinity of the LHRH neurons interacts with specific sites on the LHRH axonal terminals, which leads to release of the peptide.
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PMID:A ligand-specific action of chelated copper on hypothalamic neurons: stimulation of the release of luteinizing hormone-releasing hormone from median eminence explants. 639 Apr 43

Aggressive nutritional support of the cancer patient undergoing treatment has become widespread standard practice. In order to evaluate the effect of total parenteral nutrition (TPN) on protein metabolism, 11 patients with localized squamous cell carcinoma of the distal esophagus were studied in the postabsorptive state and again after 2 weeks of TPN. After two weeks of TPN, these cancer patients demonstrated a significant increase in body weight associated with positive nitrogen balance and an insignificant increase in total body potassium (determined by whole body 40K scanning), a measure of lean body mass. Serum transferrin, ceruloplasmin, and total protein did not change significantly, whereas serum albumin decreased significantly (3.5 +/- 0.1 to 3.1 +/- 0.1 g dl-1). Evaluation of whole-body protein kinetics by constant infusion of 15N-glycine demonstrated a significant increase in protein flux (2.79 +/- 0.20 to 4.02 +/- 0.33 g protein kg-1 day-1). In the group as a whole, protein synthesis increased and catabolism decreased, but not significantly. Skeletal muscle protein catabolism, as measured by the rate of excretion of urinary 3-methylhistidine (mumol kg-1 day-1) decreased significantly after 2 weeks of TPN (2.5 +/- 0.1 to 1.9 +/- 0.2). A change from basal to stimulated (TPN) serum insulin level of 40 to 120 microU/ml was found to be associated with optimal changes in protein synthesis and skeletal muscle catabolism. Five patients fell within this optimal range of serum insulin, and demonstrated a significant increase in the rate of wholebody protein synthesis (2.13 +/- 0.35 to 3.56 +/- 0.45 g protein kg-1 day-1) with an insignificant increase in whole-body protein catabolism (2.74 +/- 0.42 to 3.16 +/- 0.43), and a significant decrease in urinary 3-methylhistidine excretion (2.50 +/- 0.35 to 1.53 +/- 0.24) after 2 weeks of TPN. It is concluded that optimum nutritional support with TPN is beneficial to the cancer patients' protein economy by stimulating whole body protein synthesis while decreasing skeletal muscle protein catabolism. It is also concluded that there exists a range of serum insulin in which whole-body protein synthesis and catabolism are optimized.
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PMID:Whole-body protein metabolism in cancer-bearing patients. Effect of total parenteral nutrition and associated serum insulin response. 642 40

Forty-seven normal health women were studied longitudinally for changes in liver functions during the use of the levonorgestrel contraceptive implant system, NORPLANT. Samples were collected before insertion of the implants and after one, three and six months of use. The enzymes studied were the transaminases (SGOT and SGPT), alkaline phosphatase and gamma-glutamyl transferase. Serum bilirubin and bile acid levels were also measured. The protein synthetic function of the liver was tested by estimation of total proteins, albumin, transferrin, hemopexin, ceruloplasmin and haptoglobin. The three main immunoglobulins, G, M and A, were also measured. There were no significant changes in the liver enzymes after NORPLANT use. Serum bilirubin and bile acid concentrations showed rises in the first month of use which ameliorated in subsequent months. Serum albumin was transiently increased during the first and third months. Ceruloplasmin decreased significantly at the sixth month. The concentrations of total serum proteins and the other individual proteins showed no significant change. The results point to safety of NORPLANT implant use, as regards hepatic functions.
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PMID:Effect of subdermal levonorgestrel contraceptive implants, Norplant, on liver functions. 644 Jul 36

The inhibitor of the serum ferroxidases, recently detected in rabbit serum, has been purified to homogeneity from human serum by a combination of gel-filtration and ion-exchange chromatography. The molecular weight, chromatographic behavior, electrophoretic mobility, electrofocusing pH, carbohydrate content, and reactivity with anti-human albumin during immunodiffusion indicate that the ferroxidase inhibitor is serum albumin. Copper-binding studies, proteolytic fragmentation studies, and a comparison of the inhibitory potencies of several albumin species which differ in their affinity for copper strongly indicate that albumin elicits its inhibitory effect on the serum ferroxidases by interacting with the functional copper of these enzymes. Kinetic analyses further suggest that albumin competes with substrate (ferrous iron) for binding to the functional copper of the serum ferroxidases.
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PMID:Purification and characterization of the serum ferroxidase inhibitor. 644 32

Biochemical polymorphisms (haemoglobin, serum transferrin, serum albumin, serum amylase, red cell phosphohexose isomerase, red cell carbonic anhydrase, ceruloplasmin and aryl esterase) of 224 Hungarian Native female goats and 21 imported male goats (German Improved, Saanen, Nubian, Slovakian White) have been studied. On the basis of the observed gene frequency values these polymorphic traits cannot be used efficiently in parentage control work or in correlation studies. There was no apparent association between the haemoglobin and transferrin type of the females and their reproductive performance.
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PMID:Biochemical polymorphisms in goats with special reference to the Hungarian Native breed. 661 90

Human caeruloplasmin (ferroxidase), bovine serum albumin and ascorbate protected washed rat erythrocytes against iron ion stimulated haemolysis, while superoxide dismutase, catalase and other scavengers of "activated oxygen" species had little or no effect. Caeruloplasmin retained its protective action when its oxidase activity was completely inhibited by azide, and when its copper ions had been removed. The effect of caeruloplasmin, apocaeruloplasmin and albumin could not be attributed to a binding of iron ions to protein molecules.
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PMID:Iron ion induced haemolysis: effect of caeruloplasmin, albumin and ascorbate (vitamin C). 661 51

Transplantation of Yoshida sarcoma (solid type) and Zajdela ascites hepatoma tumors in rats induces a biphasic change in the concentration of the following five acute-phase proteins: alpha-1-acid glycoprotein; alpha-1-antitrypsin; haptoglobin; hemopexin; and ceruloplasmin. These proteins and other plasma proteins were quantitated by two-dimensional immunoelectrophoresis relative to normal serum concentrations. The elevation of most of these acute-phase proteins was greater in the second phase, during which serum levels increased continuously as the tumor burden increased until the animals died. The increase in haptoglobin concentration during the second phase was much higher in rats bearing Yoshida sarcoma than in rats bearing Zajdela tumors. Rats receiving irradiated tumor cells showed neither tumor growth nor second-phase protein changes. Significant increases in uptake of 3H-amino acids by isolated perfused livers of tumor-bearing rats provided evidence for an increase in the hepatic synthesis rates of the acute-phase proteins. Removal of the solid tumor resulted in a gradual decrease of acute-phase protein concentrations with concomitant increase in serum albumin concentration. These alterations in serum acute-phase proteins during tumor growth and after removal of the tumor may make their use attractive as biological markers of the response of the tumor-bearing animal to its tumor.
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PMID:Kinetics of the acute-phase reaction in rats after tumor transplantation. 697 53

Acute-phase reactant proteins reach abnormally high levels in patients with cancer, and correlate with the extent of disease. In this study, several acute-phase glycoproteins, and serum albumin as a control, were tested at different concentrations for their ability to modify the blastogenic response of lymphocytes from 30 normal donors to PHA and the chemotactic response of monocytes from 15 normal donors to casein. In high concentrations approximating those found in cancer patients, but not in normal concentrations, haptoglobin and fibrinogen inhibited both functions to different degrees. Orosomucoid inhibited only monocyte chemotaxis, while ceruloplasmin and alpha 1-antitrypsin affected neither function. Increasing concentrations of PHA did not overcome the blocking effect of haptoglobin and fibrinogen on blastogenesis, suggesting that PHA-protein interaction was not responsible for the effect observed. The three proteins that did not suppress blastogenesis individually did so strongly when combined. It is suggested that these glycoproteins, synthesized by the liver in response to an inflammatory stimulus, may act as 'non-specific blocking factors' protecting tumors against the host's immunological attack. This non-specific blocking activity of the acute-phase proteins may contribute to the 'immune escape' of the tumor.
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PMID:Immunosuppressive effect of acute-phase reactant proteins in vitro and its relevance to cancer. 698 54


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