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:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The levels of serum gamma-glutamyl transpeptidase (GGT) and, when appropriate, alkaline phosphatase (AP) and 5'-nucleotidase (NTD) have been measured as a routine in 276 patients with malignant haematological diseases during a 26-month trial period. GGT levels add no prognostic information to the routine haematological surveillance of leukaemia. Polychemotherapy does not appear to be an inducer of liver drug-metabolising microsomal enzymes. Polycythaemia rubra vera, myelofibrosis and chronic lymphocytic leukaemia may cause little change in GGT, AP and NTD levels despite marked hepatomegaly. A raised GGT in Hodgkin's disease and non-Hodgkin lymphoma is generally associated with active and widespread disease, but not necessarily a sign of malignant tissue in the liver. The elevations of GGT in myeloma may be secondary to liver infiltration though this group merits further detailed study.
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PMID:Evaluation of the usefulness of serum gamma-glutamyl transpeptidase levels in the management of haematological neoplasia. 2 19

Extracellular membraneous vesicles of GRSL leukaemia cells were isolated from the ascites fluid bathing the cells in vivo, and from cell washes. Mammary tumour virus-induced antigens (MLr) expressed on the surface of the cells are enriched on these vesicles as compared to plasma membranes isolated from the cell homogenate. The lipid fluidity of the vesicles is much smaller than that of the plasma membranes, and the content of the pertinent lipid parameters, cholesterol and sphingomyelin, are accordingly greatly increased. The extracellular vesicles which are also enriched in sialic acid and 5'-nucleotidase are apparently derived from the plasma membrane, probably at least partly by exfoliation of selected parts or domains of the surface of living cells. An analogy between this shedding of vesicles, the formation of endocytotic vesicles and the budding of viruses is noted; all these processes select or assemble rigid lipid domains of the cell membrane. The possible participation of surface microvilli and sub-lethal autolysis in the process of shedding is discussed.
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PMID:Rigid plasma-membrane-derived vesicles, enriched in tumour-associated surface antigens (MLr), occurring in the ascites fluid of a murine leukaemia (GRSL). 8 6

Mouse leukemia L-1210 cells were iodinated with 125I; this permitted the development of a method for the isolation of the plasma membranes. These show a 10- to 16-fold increase in the specific activity of 125I over that of the cell homogenate and a 20-fold increase in the specific activities of 5'-nucleotidase and alkaline phosphatase; 20-fold increase in the specific activities of 5'-nucleotidase and alkaline phosphatase; no mitochondrial or microsomal marker enzyme activities were detected. Sodium dodecyl sulfate gel electrophoresis of the plasma membranes shows approx. 40 peptides with molecular weights ranging from 10 000 to over 200 000; a polypeptide (Mr 50 000) predominates. Of 13 iodinated surface membrane proteins, the major radioactive peptide has a molecular weight of 85 000. The importance of the selection of the appropriate gel system for the analysis of membrane proteins is emphasized.
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PMID:Isolation and characterization of the plasma membrane of L-1210 cells. Iodination as a marker for the plasma membrane. 16 26

The organelle pathology of neutrophils in chronic granulocytic leukaemia (CGL) was investigated by analytical subcellular fractionation. There were minor reductions in activity of some granule enzymes with an abnormal distribution in sucrose density gradients of the specific granules. There was a marked reduction of 5'-nucleotidase activity but this is probably related to the relative reduction of the mononuclear cell contamination of the neutrophils isolated from leukaemic patients compared with controls. Another plasma membrane enzyme, NADH-nitroblue tetrazolium reductase, which has a microbicidal role, had increased activity. Neutrophils from patients with CGL had 13% the alkaline phosphatase activity of controls and were compared with neutrophils from women in the third trimester of pregnancy when the activity was increased to 8 times the control level. The latent activity, per cent inhibition by Levamisole, kinetic constants and subcellular distribution of alkaline phosphatase were similar in the three groups. It is suggested that the properties and intracellular localization of alkaline phosphatase are normal in CGL and that there is a quantitative lack of enzyme.
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PMID:Studies on the subcellular organelles of neutrophils in chronic granulocytic leukaemia with special reference to alkaline phosphatase. 28 20

The ecto-5'-nucleotidase activities of highly purified T and B lymphocytes from human peripheral blood have been investigated using biochemical and histochemical techniques. The enzyme activity of the purified B cells was about 3.5 times that of the T cells. Using a histochemical assay, 21--55% of the B cells stained positively for 5'-nucleotidase, but only 2--22% of the T cells were positive. These results are discussed in relation to the low 5'-nucleotidase activities found on peripheral blood lymphocytes from patients with chronic lymphatic leukaemia and some patients with primary hypogammaglobulinaemia.
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PMID:5'-nucleotidase of B and T lymphocytes isolated from human peripheral blood. 31 62

The activity of 5'-nucleotidase in L 1210 leukaemia cells fixed in situ by glutaraldehyde was established by electron microscopic cytochemistry and biochemical assays. The enzyme activity is localized uniquely on the cell surface. In biochemical assays the time course of phosphate liberation by the suspension of glutaraldehyde fixed cells was linear up to 15 min incubation. The activity was proportional to the number of cells in the suspension, amounting of 0.019 units activity per 10(8) cells.
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PMID:5'-Nucleotidase of L 1210 cells. Cytochemical and kinetic studies. 43 76

The microsomal fraction was isolated from homogenate of 125I-labeled leukemia L 1210 ascites cells by filtration of postmitochondrial supernatant through a Sepharose 4 B column. It was found that the particles are labeled with iodine and show 5'-nucleotidase activity suggesting the presence of cell membranes in the fraction. The soluble proteins fraction were retarded on the column showed lactate dehydrogenase activity, and low activity of soluble beta-D-glucuronidase.
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PMID:125I-labeled cell surface as a marker in preparation of microsome fraction by gel filtration. 70 May 5

The nucleoside analog acyclovir (9-[2-hydroxy-ethoxy)methyl]guanine or acycloguanosine; ACV) inhibited the in vitro transformation of NIH 3T3 cells by Abelson murine leukemia virus and the proliferation of abl- and bcr-abl-transformed hemopoietic murine cell lines. This effect is selective since ACV at the same concentration had no effect on the src and Ha-ras transformation of NIH 3T3 cells or on the proliferation of hemopoietic cells transformed by those oncogenes. The inhibitory effect on proliferation of abl-transformed cells correlated with the extent of ACV triphosphate formation and incorporation into cellular DNA that was greater than that in normal or other oncogene-transformed cells. The increased ACV triphosphate formation might be due to a higher level of 5'-nucleotidase, the enzyme responsible for trace levels of ACV phosphorylation in uninfected cells.
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PMID:Selective inhibition of proliferation in v-abl- and bcr-abl-transformed cells by a nucleoside analog. 133 Oct 46

2-Chlorodeoxyadenosine (CdA) is active in chronic lymphocytic leukemia, hairy-cell leukemia, and low-grade lymphomas. In part, this spectrum of activity may be attributable to the selective toxicity of CdA to nondividing lymphocytes and monocytes. However, CdA is unstable at acidic pH and is degraded by bacterial nucleoside phosphorylases. The present experiments demonstrate that the 2'-arabino-fluoro derivative of CdA, designated CAFdA, is also directly toxic to quiescent lymphocytes and macrophages. Unlike CdA, CAFdA was stable at pH 2 and resisted degradation by Escherichia coli nucleoside phosphorylase. Cell killing was preceded by the formation of DNA strand breaks and could be prevented by supplementation of the medium with deoxycytidine. The initial DNA damage initiated the pattern of oligonucleosomal DNA fragmentation characteristic of apoptosis. Mutant lymphoblasts, deficient in deoxycytidine kinase, with elevated cytoplasmic 5'-nucleotidase, or with expanded deoxynucleotide pools secondary to increased ribonucleotide reductase activity, were cross-resistant to both CAFdA and CdA toxicity. One-week oral treatment with CAFdA (1 mg/ml in drinking water) achieved an average plasma concentration of 0.56 microM and eliminated 90% of chronic lymphocytic leukemia cells transplanted into severe combined immunodeficiency (scid) mice. Under the same conditions, CdA was much less active. Collectively, these results suggest that CAFdA could be effective as an oral agent in indolent lymphoproliferative diseases and in autoimmune diseases where lymphocyte and monocyte depletion is desirable.
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PMID:Oral antilymphocyte activity and induction of apoptosis by 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine. 134 62

Merocyanine 540 (MC 540) is a photosensitizing dye that is used clinically for the purging of autologous bone marrow grafts and preclinically for the inactivation of enveloped viruses in blood products. Its mechanism of action is not yet well understood. This paper investigates the sites of MC 540-mediated photodamages in L1210 leukemia cells by examining the effects of MC 540-sensitized photoirradiation on several soluble and membrane-bound marker enzymes. When exposed to MC 540 and white light under a standard set of conditions, the activities of Na+/K(+)-ATPase, Mg2(+)-ATPase, and 5'-nucleotidase (three plasma membrane-bound enzymes) were reduced by 54, 49, and 55%, respectively. None of the intracellular enzymes included in this survey was affected by MC 540-sensitized photoirradiation as long as the plasma membrane remained intact. The two soluble enzymes, lactate dehydrogenase and malate dehydrogenase, remained refractory to MC 540-sensitized photoirradiation even after the plasma membrane had been disrupted. By contrast, the activities of the membrane-bound enzymes, NADPH-cytochrome c reductase and succinate dehydrogenase, were reduced in cell lysates by 55 and 81%, respectively. Purified NADPH-cytochrome c reductase was about 3 times less sensitive than the microsomal enzyme, suggesting that the membrane environment facilitated photoinactivation. The MC 540-sensitized photoinactivation of enzymes was accelerated in the presence of deuterium oxide and inhibited if oxygen in the medium was displaced by nitrogen or azide was added to the medium. Taken together, these data support the view that the plasma membrane is a major target of MC 540-mediated photodamages, that the inactivation of membrane-bound enzymes is an oxidative process, and that at least some photodynamic damages are mediated by type II chemistry.
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PMID:Merocyanine 540-sensitized photoinactivation of soluble and membrane-bound enzymes in L1210 leukemia cells. 217 31


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