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)

An assay of adenosine deaminase activity in pleural effusions is described. For the continuous determination of adenosine deaminase, the liberated ammonia is estimated by coupling the liberated NH3 with 2-oxoglutarate. The reaction is followed by the decrease of NADH absorbance at 340 nm. The assay was optimized for a Hitachi 705 analyser, with respect to pH, adenosine concentration and glutamate dehydrogenase activity. The assay is linear to an adenosine deaminase catalytic concentration of 110 U/l. Elevated adenosine deaminase activities are found in pleural effusions of patients with tuberculosis, empyema and mesothelioma. Although elevated adenosine deaminase activity in pleural effusion is not pathognomonic for tuberculosis, it may be valuable as a first screening parameter.
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PMID:A continuous method for the estimation of adenosine deaminase catalytic concentration in pleural effusions with a Hitachi 705 discrete analyser. 406 16

A microassay for adenosine deaminase is elaborated. It is based on the colorimetric measurement of small amounts of ammonia raised during adenosine deamination and separated by continuous flow dialysis. The analytical qualities of the microassay are reported. The enzymic activity concentration in whole arterial blood of 30 control subjects is 2.54 +/- 1,68 micro katal/l (mean +/- 2ET). It is slightly lower in venous blood. The values are higher in man than in women. 92 p. cent of the enzymic activity of whole blood are due to the erythrocytes. The distribution of the arterial enzymic activity concentrations is not significantly different in a group of 85 cirrhotic patients when compared to the control group. No tight correlation can be found between blood adenosine deaminase concentrations and either blood ammonia nor shed blood ammoniagenesis. Inhibitors of adenosine deaminase have little effects on the in vitro ammoniagenesis.
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PMID:[Microassay for blood adenosine deaminase: study of the role of the enzyme in the ammoniagenesis of the blood sample]. 407 6

The hydrolysis of adenosine 3'-monophosphate by serum acid phosphatase has been coupled to the liberation of ammonia from the adenosine generated through the action of exogenous adenosine deaminase. The ammonia is measured at the end of the incubation by a modification of the phenol-hypochlorite reaction of Berthelot. Optimum conditions for the enzyme reaction have been defined. Inhibition of the Berthelot reaction by the serum used in the assay is small, and may be compensated by a correction factor. Although the value for the control is high in relation to the test over the normal range, this is largely outweighed by the good sensitivity and precision of the method. The substrate is not significantly hydrolysed by erythrocyte acid phosphatase within the limits encountered in haemolysed sera. Experience of the method in routine hospital diagnosis compared favorably with that of a standard method employing disodium phenyl phosphate as substrate. It is suggested that activities greater than 3.1 IU/l should be further investigated and those greater than 3.7 IU/l should be regarded as definitely raised. The stability of human serum AcPase when promptly separated and held at 4 degrees C or - 20 degrees C was confirmed. At room temperature, acidification to pH 6.0 greatly improved stability.
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PMID:Colorimetric determination of serum acid phosphatase activity using adenosine 3'-monophosphate as substrate. 410 91

(+/-)-4 alpha-Amino-2 alpha,3 beta-dihydroxy-1 alpha-cyclopentanemethanol (6), the carbocyclic analogue of xylofuranosylamine, was synthesized from the previously reported 4 alpha-acetamido-2 alpha,3 alpha-epoxycyclopentane-1 alpha-methanol. Amine 6 was converted to (+/-)-4 alpha-[(5-amino-6-chloro-4-pyrimidinyl)amino]-2 alpha,3 beta-dihydroxy-1 alpha-cyclopentanemethanol (7) by condensation with 5-amino-4,6-dichloropyrimidine. From 7, the carbocyclic analogues of xylofuranosyladenine and xylofuranosyl-8-azaadenine were prepared. In contrast to 9-beta-D-xylofuranosyladenine and its 8-aza analogue, the corresponding carbocyclic nucleosides were resistant to deamination by adenosine deaminase. The carbocyclic 8-aza derivative 10 exhibited significant in vivo antitumor activity which varied according to treatment schedule.
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PMID:Carbocyclic analogues of xylofuranosylpurine nucleosides. Synthesis and antitumor activity. 648 72

The enzymatic deamination of adenosine to inosine produces ammonia, which causes a pH-increase of the reaction mixture. The pH-stat method is based on the continuous addition of protons to keep the pH at a constant value. The theoretical principles are discussed. The quantitative limits of the assay and the effect of changing the pH were investigated. A correction factor was derived and calculated for the pH range 6.4 to 8.5. This sensitive method allows the continuous recording of the adenosine deaminase activity in strongly coloured or turbid biological samples.
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PMID:[Continuous measurement of the catalytic activity of adenosine deaminase using the pH stat method]. 652 96

The present work describes an assay which is highly specific for ribose-5-phosphate. The method is based on the following three-stage enzymatic conversion: (1) ribose 5-phosphate in equilibrium ribose 1-phosphate (phosphopentomutase); (2) ribose 1-phosphate + adenine in equilibrium adenosine + Pi (adenosine phosphorylase); (3) adenosine + H2O----inosine + NH3 (adenosine deaminase). Ribose 5-phosphate may be determined either directly following the change in absorbance at 265 nm associated with the conversion of adenine to inosine, or radioenzymatically by measuring the radioactivity of inosine formed from [8-14C]adenine, after chromatographic separation of the nucleoside on polyethyleneimine-cellulose. The spectrophotometric assay was used to follow ribose 5-phosphate formation and ribose 1-phosphate consumption catalyzed by phosphopentomutase. Further, the ability of alkaline phosphatase, 5'-nucleotidase and crude extract of Bacillus cereus cells to act on ribose 5-phosphate was tested. The radioenzymatic assay was proved useful in determining the levels of ribose 5-phosphate in rat tissues.
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PMID:Spectrophotometric and radioenzymatic determination of ribose-5-phosphate. 653 May 7

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

In experiments with mongrel male rats the asparaginase and adenosine deaminase activities in the liver tissue and adenosine deaminase in blood serum were determined under different conditions of parenteral nutrition. The intraperitoneal administration of the preparations of parenteral nitrogen nutrition-aminosol and amikin (0.25 g of conditioned protein per 100 g of body weight) against a background of protein deficiency and exhaustion is shown to cause no changes as compared to the control of these enzymes activity in the liver tissue and blood serum. The asparaginase activity in the liver increases noticeably with the dose of aminosol and amikin up to 0.5 g of conditioned protein per 100 g of body weight and the adenosine deaminase activity undergo no essential changes. A statistically significant decrease in the adenosine deaminase activity is observed only under administration of aminosol against a background of protein deficiency. Under oral feeding of rats with amikin in the composition of protein-free (0.5 g of conditioned protein per 100 g of body weight), as distinct from its parenteral administration, the asparaginase activity in the liver is considerably lower. The adenosine deaminase activity in the liver and blood serum is not practically changed. A part of the nitrogen excreted from the organism with urea and ammonia under protein deficiency is supposed to be a product of deamination of endogenic purine and pyrimidine derivatives.
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PMID:[Dynamics of asparaginase and adenosine deaminase activity in the liver with intraperitoneal administration of aminosol and amikin preparations of parenteral nitrogen nutrition]. 680 84

The activity of adenosine deaminase (ADA) (EC3.5.4.4.) was determined in the blood plasma, erythrocytes, and lymphocytes of 23 patients with Hodgkin's disease and partly also in 99 control subjects. The enzyme activities were measured using adenosine as substrate and by analysis of ammonia. No correlation was found between the ADA activities in lymphocytes, erythrocytes, and blood plasma. The lymphocytes of the patients revealed lower ADA activities (U/g protein) than the lymphocytes of control subjects. The ADA activity is not reduced in plasma or erythrocytes. The lower activities of ADA in the lymphocytes of patients may be related to the impaired cell-mediated immunity of the Hodgkin's disease.
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PMID:[Adenosine deaminase activity in Hodgkin's disease (author's transl)]. 707 27

1. The liberation of ammonia from adenosine 5'-phosphate (AMP) and adenosine and the release of inorganic phosphate from AMP were investigated in homogenates of bovine and human parotid glands. 2. Adenosine phosphate deaminase (AMP deaminase) was purified from bovine and human parotid glands. The enzyme preparations obtained were free from adenosine deaminase and 5'-nucleotidase activities. 3. AMP incubated with human parotid gland homogenate produced inosine 5'-phosphate, adenosine, inosine and ammonia. The amount of ammonia accumulating in the incubation mixture was equal to the sum of inosine 5'-phosphate plus inosine. 4. These results demonstrate the presence in human parotid of AMP deaminase and adenosine deaminase.
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PMID:Deamination of adenosine 5'-phosphate and adenosine as a possible source of ammonia in human and bovine parotid glands. 724 42


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