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:3.5.4.17 (adenosine deaminase)
5,206 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some purine metabolizing enzymes of lymphocytes and granulocytes were determined in 13 patients with cirrhosis of the liver and in a control group consisting of 18 healthy blood donors. Furthermore cytidine deaminase (EC 3, 5, 4, 5) (CRD) activity was determined in the granulocytes of these patients and in 16 controls. An increase of adenosine deaminase (EC 3, 5, 4, 4) (ADA) activity was found in granulocytes (P less than 0.01) as well as in lymphocytes (P less than 0.01) of the cirrhotic patients as compared to controls. Purine nucleoside phosphorylase (EC 2, 4, 2, 1) (PNP) activity in granulocytes and lymphocytes was identical in the two groups. In lymphocytes of cirrhotic patients decreased hypoxanthine guanine phosphoribosyltransferase (EC 2, 4, 2, 8) (HGPRT) (P less than 0.01), adenine phosphoribosyltransferase (EC 2, 4, 2, 7) (APRT) (P less than 0.02) and adenosine kinase activities (EC 2, 7, 1, 20) (AK) (P less than 0.05) were demonstrated. 5'-nucleotidase (5'-N (EC 3, 1, 3, 5) activity in lymphocytes of cirrhotic patients was slightly increased, the increase being correlated to the level of serum gamma globulin. Granulocytes from cirrhotic patients showed a decrease of CRD (P less than 0.05). The finding that ADA activity is increased in mature lymphocytes and granulocytes from cirrhotic patients argues against the possibility that increase of lymphocytes ADA activity is a consequence of malignant transformation or immaturity.
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PMID:Changes in some nucleoside metabolizing enzymes of lymphocytes and granulocytes from patients with cirrhosis of the liver. 641 76

The activity of adenosine deaminase was determined in lymphocytes, erythrocytes and blood plasma of 73 patients with different haematological malignancies and also in healthy control subjects. The enzyme activities were measured using adenosine as substrate and by analysis of released ammonia. Statistically significant decreased enzyme levels in lymphocytes and partial also in erythrocytes were observed in chronic lymphocytic leukaemia, Hodgkin's disease and multiple myeloma. The lower activities of ADA of these patients may be related to the impaired immunological function. In contrast in myeloid leukaemia, blast crisis of myeloid leukaemia and in acute leukaemias significant increased ADA levels in lymphocytes or blast cells were observed. Between the content of blast cells in peripheral blood and ADA activity of the mononuclear cell fraction exists a positive correlation. The increased ADA values of blast cells are a sign of an elevated purine metabolism.
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PMID:[Adenosine deaminase activity in hemoblastoses]. 657 29

Isolation and characterization of 2'-deoxycoformycin from the culture filtrate of the fungus Emericella nidulance is described. Its inhibitory effect on adenosine deaminase (ADA, adenosine aminohydrolase, EC 3.5.4.4) is also described.
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PMID:Production of 2'-deoxycoformycin by the fungus Emericella nidulans and its inhibitory effect on adenosine deaminase. 660 58

JEG-3 is a human choriocarcinoma cell line characterized by low levels of adenosine deaminase expression. For the purpose of studying adenosine deaminase gene regulation in the JEG-3 cells, we attempted to select variant cells having increased adenosine deaminase expression. This was accomplished by selecting cells for resistance to the cytotoxic adenosine analogs 9-beta-D-arabinofuranosyl adenine (ara-A) or 9-beta-D-xylofuranosyl adenine (xyl-A), both of which could presumably be detoxified by the action of adenosine deaminase. Single step high dose selection was ineffective in obtaining cells with increased adenosine deaminase. However, multistep selection using either ara-A or xyl-A resulted in cell populations with increased adenosine deaminase activity. Removal of selective pressure resulted in decreased adenosine deaminase levels. Subclones of xyl-A-resistant cells belonged to one of three phenotypic classes characterized by either elevated adenosine deaminase levels, decreased adenosine kinase levels, or both of these features. One subclone (A3-1A7) with unaltered adenosine kinase expression showed a 20-fold increase in adenosine deaminase expression. Further selection of this subclone for increasing xyl-A resistance resulted in an additional 2-fold increase in adenosine deaminase expression, followed by loss of adenosine kinase expression. These adenosine kinase-deficient cells showed no subsequent increase in adenosine deaminase expression in response to further xyl-A selection pressure. These results confirmed that xyl-A toxicity was mediated through its phosphorylated form and indicated that resistance may result from increased adenosine deaminase levels and/or adenosine kinase deficiency. The increased adenosine deaminase expression of the A3-1A7 subclone was exclusively in the ADA 2 allelic form. However, cell fusion experiments between A3-1A7 cells and mouse C1-1D cells established the existence of functional copies of both ADA 1 and ADA 2 allelic genes in the A3-1A7 cells. The increased expression of only one of the two functional ADA alleles, the requirement for a stepwise selection protocol to obtain cells with increased adenosine deaminase, and the instability of the adenosine deaminase phenotype in the absence of selective pressure suggest that the alteration of adenosine deaminase phenotype in the drug-resistant cells was the result of adenosine deaminase gene amplification.
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PMID:Increased expression of one of two adenosine deaminase alleles in a human choriocarcinoma cell line following selection with adenine nucleosides. 668 74

A commercial preparation of calf adenosine deaminase (calf ADA) was further purified by affinity chromatography and used for immunization of rabbits. The resulting anti-calf-ADA sera reacted by immunodiffusion with both calf and human ADA, and precipitated about 90% of radiolabeled enzyme isolated from human thymus tissue. Moreover, ADA activity was detected in the pellets formed by immunoprecipitation of unlabeled human enzyme by anti-calf-ADA sera. These antisera were successfully used for the immunomorphologic localization of ADA in human thymus tissue and in lymphoid cell preparations. The anti-calf ADA sera could also be used for the immunofluorescent detection of enzyme in rat and mouse thymocytes. The utilization of anti-calf-ADA serum for immunochemical and immunomorphologic detection of enzyme provides a valuable and sensitive reagent for the identification of ADA-positive cells in humans and several other species.
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PMID:Detection of human, rat and mouse adenosine deaminase by immunochemical and immunomorphologic methods using antiserum to calf enzyme. 679 62

A specific competitive radioimmunoassay (RIA) was employed to quantify human adenosine deaminase molecules produced in human-Chinese hamster somatic cell hybrids. Studies on a set of hybrids in which the normal and aberrant expressions of adenosine deaminase (assigned earlier to human chromosome 20) were segregating, have demonstrated that in the patient with ADA-SCID disease reported by Herbschleb-Voogt et al. (1981 a), the deficiency of ADA activity was associated with a comparable deficiency of adenosine deaminase specific immuno-crossreacting material (ADA-CRM).
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PMID:Basic defect in the expression of adenosine deaminase in ADA-SCID disease. II. Deficiency of ADA-CRM detected in heterozygote human-Chinese hamster cell hybrids. 684 Jul 56

The somatic cell hybrid method has been used to study the number and different types of human genes involved in the expression of adenosine deaminase (ADA; adenosine aminohydrolase, EC 3.5.4.4) in normal cells and cells from a patient with ADA-deficient severe combined immunodeficiency disease (SCID). Genetic and biochemical characterization of ADA in SCID and the ADA tissue-specific isozymes in normal human cells indicates that additional genes, besides the ADA structural gene on chromosome 20, are involved in ADA expression. Human chromosome 6 encodes a gene, ADCP-1, whose presence is necessary for the expression of an ADA-complexing protein in human-mouse somatic cell hybrids [Koch, G. & Shows, T. B. (1978) Proc. Natl. Acad. Sci. USA 75, 3876-3880]. We report the identification of a second gene, ADCP-2, on human chromosome 2, that is also involved in the expression of the ADA-complexing protein. The data indicate that these two ADCP genes must be present in the same cell for that cell to express the complexing protein. Human-mouse somatic cell hybrids, in which the human parental cells were fibroblastss from an individual with ADA-deficient SCID, also required human chromosomes 2 and 6 to express the ADA-complexing protein, indicating that neither ADCP-1 nor ADCP-2 is involved in the ADA deficiency in SCID. The SCID-mouse hybrid cells expressed no human ADA even when human chromosome 20 had been retained. The deficiency of human ADA in these hybrids maps to human chromosome 20, and therefore is not due to the repression or inhibiton of ADA or its product by unlinked genes or gene products. We propose that the expression of the polymeric ADA tissue isozymes in human cells requires at least three genes: ADA on chromosome 20, ADCP-1 on chromosome 6, and ADCP-2 on chromosome 2. A genetic scheme is presented and the different genes involved in ADA expression and their possible functions are discussed.
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PMID:Somatic cell genetics of adenosine deaminase expression and severe combined immunodeficiency disease in humans. 693 68

A large collection of cultured human tumor cell lines was characterized for the phenotypes of 16 polymorphic enzyme loci: ACP1, ADA, AK1, ESD, FUCA, GLO1, GOT2, G6PD, ME2, PEPA, PEPB, PEPC, PEPD, PGD, PGM1, and PGM3 primarily to detect and monitor against cell line contamination. Among 100 highly characterized cell lines, 59 lines from different patients and 6 pairs of lines (each pair from the same patient's tumor) had unique phenotype combinations and were therefore presumed to be authentic, uncontaminated cell lines. Besides these 71 lines, the remaining 29 lines consisted of several small groups of two to three lines, each group having a different combination and being among the more frequent in the normal population. The 29 lines, therefore, were not suspected to be contaminants. Among unusual findings were the ME2 1 plus 2 phenotype determined for two bladder tumor lines, a G6PD A phenotype found in a line of Caucasian origin determined not to be a HeLa contaminant, and asymmetrical heterozygous phenotypes in several lines. Except for kidney tumor lines, there was no correlation of adenosine deaminase tissue isoenzymes between tumor lines and normal tissues of origin. For several enzymes significant deviations were found in proportions of the phenotypes observed in Caucasian cell lines from expected proportions on the basis of normal population data, indicating possible natural selection among these lines in tissue culture or among the patients of origin.
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PMID:Distinction of seventy-one cultured human tumor cell lines by polymorphic enzyme analysis. 693 74

We have determined concentrations of adenosine, deoxyadenosine, and deoxyATP (dATP) in cord blood from an infant prenatally diagnosed as ADA deficient. Plasma deoxyadenosine and adenosine were already elevated in cord blood (0.7 and 0.5 microM vs. normal of less than 0.07 microM). Elevation of plasma deoxyadenosine has not previously been documented in these children. Erythrocyte dATP content was also elevated at birth (215 nmol/ml packed erythrocytes vs. normal of 2.9). These elevated concentrations of adenosine, deoxyadenosine, and dATP are similar to those we observed in another older adenosine deaminase-deficient patient and may explain the impaired immune function and lymphopenia seen at birth.
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PMID:Plasma deoxyadenosine, adenosine, and erythrocyte deoxyATP are elevated at birth in an adenosine deaminase-deficient child. 696 96

The purpose of this paper was to study the heterogeneity of human thymocytes and leukemic cells of the T-cell line MOLT-3 by velocity sedimentation. Analysis of the subpopulations of thymocytes demonstrated that they represent a heterogeneous population of cells with respect to their size, proliferative activity, and presence and quantities of terminal deoxynucleotidyl transferase and human thymus leukemia-associated antigen, a thymic isozyme of adenosine deaminase (HThy-L/ADA). Only a minor subpopulation of thymocytes (large cells) was in active cycle. The highest level of HThy-L/ADA was associated with the main subpopulation of thymocytes sedimenting at 3 to 4 mm/hr while low amounts of the HThy-L/ADA antigen (enzyme) were found in the minor fractions of the small and large cells. The distribution of terminal deoxynucleotidyl transferase-positive cells indicated that most, but not all, thymocytes contain the enzyme. Analysis of the T-cell line MOLT-3 showed that these cells could be separated into subpopulations with different biochemical and biological properties. More than one subpopulation of cells was capable of DNA synthesis. In contrast to the thymocytes, all fractions of MOLT-3 cells contained high amounts of HThy-L/ADA. The proportion of terminal deoxynucleotidyl transferase-positive cells as a function of sedimentation velocity was also quite constant although there was a slight but reproducible drop in the percentage of these cells in the slowly sedimenting fractions. The percentage of cells with receptors for sheep erythrocytes also remained high in fractions separated on the basis of size, although a consistently higher percentage was found in smaller cells. These studies indicated that thymus cells as well as the malignant T-cell line MOLT-3 can be separated on the basis of sedimentation velocity into subpopulations with different biological and biochemical properties. The data also indicated that the heterogeneity of MOLT-3 line cannot be explained solely on the basis of volume changes due to cell cycle, suggesting that they may represent heterogeneous populations of cells.
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PMID:Heterogeneity of human thymocytes and a malignant T-lymphoblast cell line, MOLT-3. 697 Nov 48


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