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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenosine deaminase and adenosine kinase have been measured in rat liver, 12 transplantable hepatomas, regenerating, foetal and neonatal liver, adult and neonatal rat kidney and 2 transplantable kidney tumours. Adenosine, deaminase activity, relative to the normal liver value, was elevated 2-4 fold in hepatomas of rapid growth rate, was in the normal range in more slowly growing hepatomas and in regernerating liver, and was low in foetal and neonatal liver. Adenosine kinase activity was decreased, relative to rat liver values, in all the hepatomas; activity of this enzyme gave a negative correlation with tumour growth rate. Kinetic properties of the two enzymes were examined in partially purified preparations. Adenosine deaminases from both liver and rapidly growing hepatoma 3924A were subject to weak product inhibition by inosine. Adenosine kinase from liver and hepatoma 3924A was inhibited by the reaction products ADP and AMP, and the enzyme was also subject to excess substrate inhibition by concentrations of ATP in excess of 1 mM. In rat hepatoma cell lines growing in culture, the toxicity of adenosine correlated inversely with the ratio of adenosine deaminase activity to adenosine kinase activity. Chromatographic measurements showed that hepatoma cells incorporated less extracellular adenosine into their adenine nucleotide pools than did isolated liver cells. These results indicate that increased adenosine deaminase activity and decreased adenosine kinase activity may confer a selective advantage upon the cancer cell.
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PMID:Adenosine deaminase and adenosine kinase in rat hepatomas and kidney tumours. 20 96

1. AMP-deaminase activity in erythrocytes increases gradually during chick (Gallus domesticus) maturation, reaching the adult level of enzymatic activity at about 16 weeks after hatching. 2. Adenosine deaminase activity increases approximately two-fold during this period. 3. Substrate specificity and immunoinhibition studies indicate that erythrocytes from adult chickens and newly-hatched chicks contain the same AMP-deaminase isozyme. 4. Comparison of temporal changes in RBC AMP-deaminase with those previously described for this enzyme in muscle and brain suggests that the level of this enzyme is regulated differently in these tissues.
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PMID:Erythrocyte AMP-deaminase: an investigation of the increase in activity during chick maturation. 31 90

The role of adenosine in postprandial jejunal hyperemia was investigated by determining the effect of placement of predigested food into the jejunal lumen on blood flow and oxygen consumption before and during intra-arterial infusion of dipyridamole (1.5 microM arterial concn) or adenosine deaminase (9 U/ml arterial concn) in anesthetized dogs. Neither drug significantly altered resting jejunal blood flow and oxygen consumption. Before dipyridamole or deaminase, food placement increased blood flow by 30-36%, 26-42%, and 21-46%, and oxygen consumption by 13-22%, 21-22%, and 26-29%, during 0- to 3-, 4- to 7-, and 8- to 11-min placement periods, respectively. Adenosine deaminase abolished the entire 11-min hyperemia, whereas dipyridamole significantly enhanced the initial 7-min hyperemia (45-49%). Both drugs abolished the initial 7-min food-induced increase in oxygen consumption. Dipyridamole attenuated (14%), whereas deaminase did not alter (28%), the increased oxygen consumption that occurred at 8-11 min. Adenosine deaminase also prevented the food-induced increase in venoarterial adenosine concentration difference. In separate series of experiments, luminal placement of food significantly increased jejunal lymphatic adenosine concentration and release. Also, reactive hyperemia was accompanied by an increase in venous adenosine concentration and release. This study provides further evidence to support the thesis that adenosine plays a role in postprandial and reactive hyperemia in the canine jejunum.
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PMID:Role of adenosine in postprandial and reactive hyperemia in canine jejunum. 141 8

Spontaneously beating rat heart Langendorff preparations, perfused with Tyrode solution under low flow conditions (1.62 +/- 0.47 ml/min at 55 mmHg), were used to investigate the role of adenosine in the coronary flow control, by means of adenosine-deaminase injections into the perfusion system. Adenosine deaminase did not influence the control coronary flow, but significantly reduced autoregulation, hypoxic vasodilation, reactive hyperemia and functional adrenaline-induced hyperemia. All these effects, excepting the hypoxic vasodilation reduction, dependent upon the moment of enzyme injection during the experiment. Under the mentioned conditions adenosine seems to be responsible for more than half of the autoregulation of the coronary flow. Adenosine deaminase completely abolished reactive hyperemia during control perfusion but only delayed it under adrenaline perfusion.
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PMID:Short-time adenosine deaminase interventions upon underperfused rat hearts in vitro--a test for the role of adenosine in the coronary flow control. 250 80

By means of agonist and enzyme experiments, the relative importance of endogenous adenosine, adenine nucleotides or other purines as modulators of cholinergic neuroeffector transmission in preparations of guinea-pig ileum muscle has been examined. Adenosine, 2-chloroadenosine, AMP, ADP, ATP and AMPPNP reversibly inhibited contractile responses to transmural stimulation of the guinea-pig ileum longitudinal muscle. 5'-adenylate deaminase dose-dependently antagonized the inhibitory effect of adenosine, AMP, ADP, ATP and AMPPNP, but not that of 2-chloroadenosine. 8-p-sulphophenyltheophylline, adenosine deaminase and 5'-adenylate deaminase enhanced contractile responses to transmural nerve stimulation. Adenosine deaminase and 5'-adenylate deaminase were virtually equiactive whereas 8-p-sulphophenyltheophylline was much more effective, and the theophylline derivative also enhanced contractile responses in preparations pretreated with adenosine deaminase or 5'-adenylate deaminase. Moreover, 8-p-sulphophenyltheophylline abolished the inhibition by dipyridamole, whereas adenosine deaminase and 5'-adenylate deaminase only partly antagonized the inhibitory effect of dipyridamole. Application of 5'-adenylate deaminase did not enhance the nerve-induced contractions in preparations pretreated with adenosine deaminase or a combination of dipyridamole and adenosine deaminase. In conclusion, adenosine deaminase and 5'-adenylate deaminase enhanced the nerve-induced contractions in the ileum, and, since 5'-adenylate deaminase was inactive after pretreatment with adenosine deaminase, this suggests that endogenous adenosine rather than 5'-adenine nucleotides modulated cholinergic neurotransmission in the ileum.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:On the nature of endogenous purines modulating cholinergic neurotransmission in the guinea-pig ileum. 282 30

5'-Nucleotidase, adenosine phosphorylase, adenosine deaminase and purine nucleoside phosphorylase, four enzymes involved in the utilization of exogenous compounds in Bacillus cereus, were measured in extracts of this organism grown in different conditions. It was found that adenosine deaminase is inducible by addition of adenine derivatives to the growth medium, and purine, nucleoside phosphorylase by metabolizable purine and pyrimidine ribonucleosides. Adenosine deaminase is repressed by inosine, while both enzymes are repressed by glucose. Evidence is presented that during growth of B. cereus in the presence of AMP, the concerted action of 5'-nucleotidase and adenosine phosphorylase, two constitutive enzymes, leads to formation of adenine, and thereby to induction of adenosine deaminase. The ionsine formed would then cause induction of the purine nucleoside phosphorylase and repression of the deaminase. Taken together with our previous findings showing that purine nucleoside phosphorylase of B. cereus acts as a translocase of the ribose moiety of inosine inside the cell (Mura, U., Sgarrella, F. and Ipata, P.L. (1978) J. Biol Chem. 253, 7905-7909), our results provide a clear picture of the molecular events leading to the utilization of the sugar moiety of exogenous AMP, adenosine and inosine as an energy source.
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PMID:Induction and repression of enzymes involved in exogenous purine compound utilization of Bacillus cereus. 627 19

Adenosine deaminase (ADA), 5'nucleotidase (5'NT), ecto-5'NT, purine nucleoside phosphorylase (PNP), hypoxanthine-guanine phosphoribosyltransferase (HGPRT), adenine phosphoribosyltransferase (APRT), adenosine kinase (AK), AMP-deaminase (AMPD) and adenylate kinase (AdKin) activities were assayed in peripheral blood lymphoid cells from 20 patients with B-cell type chronic lymphocytic leukemia (CLL). Significantly decreased mean activities of ADA, 5'NT, ecto-5'NT, PNP and AMPD were observed when comparing B-CLL lymphoid cells with control peripheral blood lymphocytes (PBL). AK and AdKin activities however, were found to be higher in B-CLL. Relatively wide ranges of ADA and 5'NT activity were observed. In patients with paraproteinaemia, 5'NT activity was found to be relatively high and in the range of the activities in normal PBL. ADA activity seemed to be slightly higher in patients without paraproteinaemia. No correlation could be found between the enzyme activities and the number of cells rosetting with sheep erythrocytes or bearing surface immunoglobulin (sIg). A relationship was suggested between 5'NT activity and Ig production.
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PMID:Enzymological studies in chronic lymphocytic leukemia. 640 72

Adenosine deaminase from Bacillus cereus is quite unstable, similarly to other bacterial deaminases, but it shows a peculiar stabilizing effect by some monovalent cations. These include K+, Li+, NH4+ and to a lesser extent Cs+. Maximal stabilization of the deaminase is exerted by K+ at concentrations higher than 20 mM. The enzyme can be rapidly inactivated by sulphydryl reagents such as p-hydroxymercuribenzoate. Since adenosine deaminase from B. cereus, in addition to monovalent cations, is stabilized also by dithiothreitol, a possible influence of monovalent cations on the reactivity of some sulphydryl groups on the enzyme has been suggested.
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PMID:Preliminary characterization of adenosine deaminase from Bacillus cereus. 681 69

Adenosine deaminase activity has been measured in red cells from individuals of known ADA phenotype (ADA 1, ADA 2-1, ADA 3-1, ADA 3-2) using adenosine and 2'-deoxyadenosine as substrates. No significant differences were observed among the phenotypes in their relative deaminase activity with the two substrates. However, evidence suggests the occurrence of an uncommon allele designated ADA1w determining low levels of ADA activity. The deaminase activities of the phenotypes were in the order ADA 1 greater than ADA 2-1 greater than ADA 3-1 greater than ADA 3-2 with both substrates. The relative activities of the alleles were estimated to be: ADA1 100%, ADA2 89%, ADA3 28% and ADA1w 67% with adenosine, and ADA1 100%, ADA2 87%, ADA3 39% and ADA1w 66% with 2'-deoxyadenosine. The Michaelis constants for adenosine and 2'-deoxyadenosine were determined for the different phenotypes. There were no significant differences in these values among the phenotypes.
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PMID:A comparison of the kinetic properties of the common and rare variants of adenosine deaminase. 697 51

Adenosine deaminase in the hypothalamic tuberomammillary nucleus and median eminence of rat and mouse brains was investigated with two different antibodies generated against the enzyme derived from either calf or mouse. Both antibodies labelled neurons in the tuberomammillary nucleus and, as determined in rat, they immunolabelled the same neurons. In the median eminence, immunopositive fibres and terminals were detected with anti-mouse adenosine deaminase in both rat and mouse, while no such staining was seen in either species with antibody against the calf enzyme. These fibres were most concentrated in the external median eminence, had a more restricted distribution than those containing either galanin or tyrosine hydroxylase and only partially overlapped with oxytocin-positive fibres. By electron microscopy, adenosine deaminase was found in terminals containing both small, clear vesicles with diameters of 35 to 45 nm and large dense-core vesicles with diameters of 100 to 140 nm. Preadsorption of antibodies with purified enzyme derived from the species against which they were directed eliminated all staining in rat, while antibody adsorptions across species were less effective. Preadsorption of anti-mouse adenosine deaminase antibody with the mouse deaminase led to increased labelling in mouse median eminence, suggesting an interaction between tissue components and antibody-linked enzyme. Tests for the presence of adenosine deaminase-complexing protein (CD26) with an antibody against this protein gave positive labelling in the median eminence of both species and this labelling was co-distributed with that seen for adenosine deaminase. These results confirm the expression of adenosine deaminase in restricted populations of neurons in rodent brain as revealed with a novel antibody, suggest the presence of a distinct form or localization of the enzyme in the median eminence, and raise the possibility that it contributes, perhaps along with CD26, to purinergic regulation of hormone secretion in this structure.
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PMID:Adenosine deaminase in rodent median eminence: detection by antibody to the mouse enzyme and co-localization with adenosine deaminase-complexing protein (CD26). 878 62


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