Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The levels of purine enzyme activities were studied in 10 patients with acquired immunodeficiency syndrome (AIDS) or AIDS related complex (ARC) and in 6 healthy individuals with antibodies against human immunodeficiency virus (HIV). All AIDS/ARC patients studied had ecto-5'nucleotidase (ecto-5'NUC) activity in B lymphocytes below the normal range and 4 out of 6 clinically healthy HIV-positive likewise had reduced activity. Increased numbers of activated B lymphocytes were found both in the group of healthy HIV positive individuals and in AIDS/ARC patients. Further studies are needed to define whether the decrease in ecto-5'NUC activity on the B lymphocytes is a result of increased activation of the cells or of a B cell defect. No significant changes were found in ecto-5'NUC levels in T lymphocytes or mononuclear cells (MNC), neither in the group of AIDS/ARC patients nor in the healthy HIV-positive group. Both AIDS/ARC patients and healthy individuals with antibodies against HIV had increased levels of adenosine deaminase (ADA) activity in mononuclear cells, but only in the group of AIDS/ARC patients was the increase significant. No changes were found in purine nucleoside phosphorylase (PNP) activity in the two groups tested. From these investigations of purine enzyme levels and other markers of immune function in both sick and healthy HIV infected individuals we conclude that the observed changes in ecto-5'NUC and ADA activities in HIV infected patients are not a direct result of the HIV infection but develop early in the course of the disease.
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PMID:Decreased B lymphocyte ecto-5'nucleotidase and increased adenosine deaminase in mononuclear cells from patients infected with human immunodeficiency virus. 284 68

Activities of the enzymes, responsible for degradation of purine nucleotides in leukocytes, were distinctly dissimilar in M1, M2, M4 and M6 variants of acute non-lymphoblastic leukosis studied in 34 patients. Differentiation of leukemic cells was shown to be due to alterations in activity of adenosine deaminase and purine nucleoside phosphorylase, which were oppositely directed as compared with those observed in lymphoblasts under conditions of acute lymphoblast leukosis. Evaluation of activities of adenosine deaminase, purine nucleoside phosphorylase and 5'-nucleotidase is of importance for characteristics of individual variants of acute non-lymphoblastic leukosis and for elucidation of the state of leukemic clone differentiation, which may affect the efficiency of the therapeutic measures used.
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PMID:[Degradation of purines in leukocytes in acute nonlymphoblastic leukemias]. 285 90

The 5'-deoxy-5'-iodo-substituted analogs of adenosine and inosine are cytotoxic to tumor cells that have high activities of 5'-methylthioadenosine phosphorylase and purine nucleoside phosphorylase, respectively (Savarese, T.M., Chu, S-H., Chu, M.Y., and Parks, R. E., Jr. (1984) Biochem. Pharmacol. 34, 361-367). 5-Iodoribose 1-phosphate (5-IRib-1-P), the common intracellular metabolite of these 5'-iodonucleosides, has been synthesized enzymatically from 5'-deoxy-5'-iodoadenosine via adenosine deaminase from Aspergillus oryzae and human erythrocytic purine nucleoside phosphorylase. The purification and chemical properties of 5-IRib-1-P are described. The analog sugar phosphate inhibited purine nucleoside phosphorylase from human erythrocytes, phosphoglucomutase from rabbit muscle, and 5'-methylthioadenosine phosphorylase from Sarcoma 180 cells with Ki values of 26, 100, and 9 microM, respectively. Enzymes that react with 5-phosphoribosyl 1-pyrophosphate (P-Rib-PP), P-Rib-PP amidotransferase, hypoxanthine-guanine phosphoribosyltransferase, adenine phosphoribosyltransferase, and orotate phosphoribosyltransferase-orotidylate decarboxylase from extracts of Sarcoma 180 cells, were inhibited with Ki values of 49, 465, 307, and 275 microM, respectively. 5-IRib-1-P had no effect on P-Rib-PP synthetase. Since the Ki values of the analog sugar phosphate for 5'-methylthioadenosine phosphorylase and P-Rib-PP amidotransferase are much lower than the Km values of the natural substrates, Pi or P-Rib-PP which are reported to be present at nonsaturating concentrations under physiological conditions, these enzymes could be significantly inhibited by 5-IRib-1-P in intact cells.
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PMID:5-Iodoribose 1-phosphate, an analog of ribose 1-phosphate. Enzymatic synthesis and kinetic studies with enzymes of purine, pyrimidine, and sugar phosphate metabolism. 293 89

The activities of a number of purine metabolizing enzymes of erythrocytes and lymphocytes were determined in 18 subjects with Down's syndrome and in 18 age- and sex-matched control subjects. An increase of adenosine deaminase activity (adenosine or deoxyadenosine as substrates) was found in erythrocytes (P less than 0.001) as well as in lymphocytes (P less than 0.001) of Down's syndrome subjects compared to controls. The purine nucleoside phosphorylase activities in lymphocytes and plasma urate concentrations were also significantly higher in Down's syndrome subjects than in controls (P less than 0.001 and less than 0.02, respectively). Adenine phosphoribosyltransferase activities and hypoxanthine-guanine phosphoribosyltransferase activities in lymphocytes were identical in the two groups. In all subjects studied there were positive correlations between the erythrocyte adenosine deaminase activities, lymphocyte adenosine deaminase or deoxyadenosine activities, and plasma urate concentrations (P less than 0.05 in all cases), and between lymphocyte nucleoside phosphorylase and lymphocyte adenosine deaminase or deoxyadenosine deaminase activities (P less than 0.01 and less than 0.05, respectively). The results suggest that increased activities of some purine metabolizing enzymes found in both erythrocytes and lymphocytes may contribute to increased purine degradation and hyperuricemia in subjects with Down's syndrome. In addition, the increased adenosine deaminase and nucleoside phosphorylase activities may be related to the immunological dysfunction found in subjects with Down's syndrome.
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PMID:Levels of some purine metabolizing enzymes in lymphocytes from patients with Down's syndrome. 294 6

This report summarises the current knowledge regarding the clinical utility of biochemical enzyme markers for both diagnostic and therapeutic purposes in acute leukaemia. The enzymes studied most extensively in this field are terminal deoxynucleotidyl transferase, adenosine deaminase, 5'-nucleotidase, purine nucleoside phosphorylase, and acid phosphatase, esterase, hexosaminidase isoenzymes. For each enzyme, the quantitative and qualitative characteristics in various immunologically defined subclasses of acute leukaemia are described. The quantitative evaluation of enzyme activities represents an adjunctive classification technique which should be incorporated into the multivariate analysis, the "multiple marker analysis." By qualitative characterisation pronounced heterogeneity of leukaemia subsets is uncovered. The application of 2'-deoxycoformycin, a specific inhibitor of adenosine deaminase, and the potential usefulness of two other enzymes as targets for treatment with selective agents is discussed. The concept that gene products expressed at certain developmental stages of normal cells can similarly be detected in leukaemic cells (which therefore seem to be "frozen" or "arrested" at this particular maturation/differentiation stage) is supported by the results obtained in enzyme studies. Besides their practical clinical importance for classification and treatment of acute leukaemias, biochemical enzyme markers constitute a valuable research tool to disclose biological properties of leukaemic cells.
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PMID:Biochemical enzyme analysis in acute leukaemia. 298 4

Cord blood lymphocytes (CBL) have been shown to be functionally immature compared with normal circulating adult lymphocytes (NAL). Differentiation of T cells is associated with changes in surface antigenic markers and in the pattern of purine degradative enzymes. Previous studies have demonstrated that thymosin fraction 5 (TMS-F5) and thymosin alpha 1 (TMS-alpha 1) can induce in vitro differentiation of murine T-cell precursors and human thymocytes. We have investigated the effects of TMS-F5 and TMS-alpha 1 on the pattern of the purine degradative enzymes adenosine deaminase, purine nucleoside phosphorylase, and ecto-5'-nucleotidase (5'NT) of CBL and on the phenotypic markers from the OKT series 3, 4, 8 and 11. Other than a significantly reduced level of 5'NT activity (P less than 0.001) and an elevated percentage of OKT4+ cells (P less than 0.01), CBL demonstrated the same immunological and biochemical patterns as NAL. Incubation of CBL with TMS-F5 (150 micrograms/ml) and TMS-alpha 1 (1 microgram/ml) for 40 h caused a significant rise in 5'NT level and decrease of cells positive for OKT4, resulting in a pattern characteristic of NAL. Thus TMS-F5 might induce the terminal differentiation of CBL, and TMS-alpha 1 seemed to be the active component.
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PMID:Terminal differentiation of cord blood lymphocytes induced by thymosin fraction 5 and thymosin alpha 1. 298 76

The enzymatic inosine 5'-monophosphate assay described by Grassl [in, Methods of Enzymatic Analysis (H. U. Bergman, ed.), pp. 2168-2171, Academic Press, New York (1974)] is highly nonspecific, as ITP, ATP, ADP, AMP, and adenosine react stoichiometrically. The reactivity with the adenine derivatives is due to the tri- and diphosphatase activity of alkaline phosphatase (AP), coupled with adenosine deaminase (and possibly AMP deaminase) contamination of commercially available preparations of AP, purine-nucleoside phosphorylase, and/or xanthine oxidase. The inclusion of coformycin (0.05 microgram/ml), a potent inhibitor of these deaminases, completely eliminated the cross-reactivity. ITP, however, still reacted stoichiometrically due to the tri- and diphosphatase activity of AP. Meyer and Terjung [Amer. J. Physiol. 237 C111-C118 (1979)] introduced a modification of Grassl's procedure, substituting 5'-nucleotidase for AP. It has been found that this disallows reactivity with ATP, ADP, and ITP but that AMP and adenosine still react completely. Coformycin prevents this cross-reactivity. It is therefore recommended that the assay be carried out with 5'-nucleotidase (instead of AP) and coformycin, in order to achieve a more specific assay, and one more suitable for use with whole tissue extracts.
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PMID:An enzymatic inosine 5'-monophosphate assay of increased specificity. 298 81

A microassay requiring as few as 2 X 10(5) cells per assay was developed for systematic analysis of 9 purine enzymes in lymphocytes from equine peripheral blood, spleen, lymph node, thymus and bone marrow. The activities of adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), adenosine kinase (AK), deoxyadenosine kinase (dAK), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-N), AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase (HGPRT or HPRT), and adenine phosphoribosyl transferase (APRT) were measured by this microassay in lymphocytes from peripheral blood from four different breeds of horses (Arabian, Quarter Horse, Thoroughbred and Shetland Pony). There were no significant differences in the enzyme activities among the various breeds. Peripheral blood lymphocytes (PBL) from foals exhibited enzyme activities similar to those observed for adult animals. All lymphoid tissue contained similar levels of activity for each kinase (AK, dAK and dCK). Spleen had the highest activity for ADA, PNP, 5'-N, and HGPRT. The lowest activity for ADA, APRT, PNP and AMP deaminase was found in thymus. Enzymatic activities that varied the most among the tissue were 5'-N, ADA, APRT, HGPRT and AMP deaminase.
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PMID:Distribution of enzymes of purine metabolism in lymphocytes of horse, Equus caballus. 299 Aug 11

Activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) as well as their ratio in chronic lymphocytic leukemia (CLL) were found to be several times lower as compared with normal cells and to depend upon the duration and severity of leukemic process. Ratio of ADA and PNP activities in CLL was inverted as compared with those of normal cells; 5'-nucleotidase activity varied within all the stages of the disease from zero values to supernormals. There was a correlation between beneficial effects of treatment of the CLL patients and an increase in ADA and PNP activities in their peripheral lymphocytes.
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PMID:[Enzymes of purine nucleotide catabolism in lymphocytes in normal states and in chronic lymphoid leukemia]. 299 63

Thymosin fraction 5 (Thymosin) has numerous immunoregulatory activities including modulation of enzymes involved in lymphocyte maturation. The effect of Thymosin on the purine metabolic enzymes adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5' nucleotidase (5'NT) in null and T-enriched peripheral blood lymphocytes from sexually active asymptomatic homosexual males (AS), patients with the AIDS-related symptom complex (ARC), and those with acquired immune deficiency syndrome (AIDS) was examined and compared to its effect on lymphocytes from healthy heterosexual controls. Mean ADA activity was significantly higher in null cells from fourteen AIDS patients than in five asymptomatic homosexuals, ten ARC patients, or 27 controls. Mean PNP activity was significantly elevated in null-enriched lymphocytes from ten ARC and fourteen AIDS patients compared to controls. No differences in these enzymes were found in T-enriched cells from any group. 5'NT was markedly decreased in both null and T lymphocytes in all homosexual groups relative to controls. Homosexuals had significantly elevated percentages of OKT10 positive and Ia positive lymphocytes compared to controls. Thymosin at an optimal concentration of 150 micrograms/ml caused significant decreases in mean ADA and PNP activity in null lymphocytes from ARC + AIDS patients along with a significant decrease in the percentage of OKT10 positive lymphocytes. No phenotypic changes were seen in AS or control lymphocytes. The data suggest that Thymosin has a maturational effect in vitro on immature T cells from symptomatic homosexuals.
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PMID:In vitro modulation of purine enzyme metabolism and lymphocyte surface marker expression by thymosin fraction 5 in homosexual males. 299 64


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