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)

Two forms of adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4), differing in molecular size, have been purified and obtained in homogeneous form from rabbit intestine. The purification procedures involved extraction with acetate buffer, pH 5.5, precipitation and fractional reextraction with (NH4)2SO4, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-75 and Sephadex G-200. Gel filtrations analysis gave molecular weight estimates of 265 000 and 32 000 for the large and small deaminases respectively. The two enzymes forms had similar pH optima and pH stability ranges.
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PMID:Purification of multiple forms of adenosine deaminase from rabbit intestine. 0 39

Adenosine deaminase exists in multiple molecular forms in human tissue. One form of the enzyme appears to be "particulate". Three forms of the enzyme are soluble and interconvertible with apparent molecular weights of approximately 36,000, 114,000, and 298,000 (designated small, intermediate, and large, respectively). The small form of adenosine deaminase is convertible to the large form only in the presence of a protein, which has an apparent molecular weight of 200,000 and has no adenosine deaminase activity. This conversion of the small form of the enzyme to the large form occurs at 4 degrees, exhibits a pH optimum of 5.0 to 8.0, and is associated with a loss of conversion activity. The small form of the enzyme predominates in tissue preparations exhibiting the higher enzyme-specific activities and no detectable conversion activity. The large form of adenosine deaminase predominates in tissue extracts exhibiting the lower enzyme specific activities and abundant conversion activity. The small form of adenosine deaminase shows several electrophoretic variants by isoelectric focusing. The electrophoretic heterogeneity observed with the large form of the enzyme is similar to that observed with the small form, with the exception that several additional electrophoretic variants are uniformly identified. No organ specificity is demonstrable for the different electrophoretic forms. The kinetic characteristics of the three soluble molecular species of adenosine deaminase are identical except for pH optimum, which is 5.5 for the intermediate species and 7.0 to 7.4 for the large and small forms.
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PMID:Human adenosine deaminase. Distribution and properties. 0 88

1. Purine nucleoside phosphorylase and adenosine deaminase (ADA) were studied in normal red blood cells and lymphocytes and in the cells of a family with a child with a defective T-cell-and normal B-cell immunity. 2. In the propositus no purine nucleoside phosphorylase (NP) activity could be detected in her red cells and lymphocytes, while the ADA activity was somewhat increased. The NP activities of the father, mother and brother of the propositus are in the heterozygote range. The decreased activity of NP was not only found for the substrate inosine but also when guanosine or xanthosine were used as substrate. The mode of inheritance is autosomal recessive. 3. With starch gel electrophoresis no NP activity could be detected in the patient's haemolysate. The electrophoretic patterns of NP from the father, mother and brother of the patient seem to be the same as for normal NP with six bands of NP activity. 4. The nucleoside phosphorylases of the father, mother and brother of the patient were characterized by an increased KM for the substrate inosine, normal pH optimum and a decreased heat stability.
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PMID:An abnormal form of purine nucleoside phosphorylase in a family with a child with severe defective T-cell-and normal B-cell immunity. 1 Jan 3

Human erythrocyte adenosine deaminase has been purified approximately 800,000-fold to apparent homogeneity using antibody affinity chromatography. The enzyme was shown to be a single polypeptide chain with an estimated molecular weight of approximately 38,000. The three electrophoretic forms of erythrocyte adenosine deaminase purified simultaneously by this technique were indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Several properties of the highly purified adenosine deaminase including pH optimum, Km for substrate, Ki for product, Stokes radius, sedimentation coefficient, and apparent substrate specificity were identical with the properties observed with an impure preparation of the enzyme.
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PMID:Human adenosine deaminase. Purification and subunit structure. 1 62

The existence of nonadrenergic, noncholinergic nerve components in the autonomic nervous system is now well established. They are strongly represented in the gastrointestinal tract of all vertebrates and have been identified in a variety of other organs, including lung, trachea, bladder, esophagus, eye, seminal vesicles, and possibly parts of the vascular and central nervous systems. Their ultrastructural identification and transmission properties are known and their physiological role is beginning to be understood, at least in the gastrointestinal tract. Evidence that ATP is the transmitter released from nonadrenergic, noncholinergic (purinergic) nerves includes: (a) synthesis and storage of ATP in nerves; (b) release of ATP from the nerves when they are stimulated; (c) exogenously applied ATP mimicking the action of nerve-released transmitter, both producing a specific increase in K+ conductance; (d) the presence of Mg-activated ATPase, 5'nucleotidase, and adenosine deaminase, enzymes, which inactivate ATP; (e) drugs (including 2-substituted imidazolines, 2,2'-pyridylisatogen and dipyridamole), that produce similar blocking or potentiating effects on the response to exogenously applied atp and nerve stimulation.
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PMID:Purine nucleotides. 1 17

In a 51/2-month-old male infant with adenosine deaminase-positive severe combined immunodeficiency disease, who had no suitable bone marrow donor, immunologic reconstitution was attempted with lymphoid cells obtained from the liver of a 4- to 5-week-old-male human embryo. A mild graft-versus-host reaction began three weeks later. T-cells, which were absent prior to infusion of hepatic lymphoid cells, rose to a maximum of 554/mm3 at 16 weeks post transplantation. A normal lymphocyte response to pokeweek mitogen was not present until 25 to 30 weeks and to allogeneic cells until 39 weeks. Postive in vitro lymphocyte responses to Candida albicans were found repeatedly after 52 weeks. Twenty months following transplantation the patient is free of clinical infection, although he requires regular injections of gamma globulin.
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PMID:Reconstitution of T-cell function in severe combined immunodeficiency disease following transplantation of early embryonic liver cells. 1 4

The use of L-glutamate dehydrogenase (GLUD) as a reagent in staining mixtures to detect the isozymes of enzymes which catalyze the production of ammonia has been investigated. Methods have been devised for the electrophoresis and detection, using GLUD, of seven enzymes: cytidine deaminase, adenosine deaminase, adenosine monophosphate deaminase, arginase, argininosuccinase, D-amino acid oxidase, and D-aspartate oxidase. GLUD-linked staining methods appear to be sensitive, specific, and of general application.
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PMID:Detection after electrophoresis of enzymes involved in ammonia metabolism using L-glutamate dehydrogenase as a linking enzyme. 2 58

A number of infants with an autosomal recessive form of combined immunodeficiency disease also lack adenosine deaminase (adenosine aminohydrolase; EC 3.5.4.4) activity in their erythrocytes. Other tissues from these infants contain only a few percent of the adenosine-deaminating activity present in corresponding normal tissue. The residual adenosine-deaminating activity in extracts from the spleen of a combined immunodeficient, adenosine deaminase-deficient patient was compared with adenosine deaminase from normal spleen. Affinity and immunoadsorbant column chromatography revealed distinct differences between the adenosine-deaminating activity in the patient's spleen and adenosine deaminase from normal spleen. The point of maximum activity and general configuration of the pH optimum curves were also different. erythro-9-(2-Hydroxyl-3-nonyl)adenine, a potent inhibitor of adenosine deaminase from normal spleen, had relatively little effect on the activity from the patient's spleen. In contrast, adenine was a better inhibitor of the activity in the patient's spleen than it was of the enzyme from normal tissue. An adenosine-deaminating activity with the same characteristics and specific activity as that in the patient's spleen was also isolated from normal spleen. These results suggest that the adenosine-deaminating activity in the spleen of this patient is not due to a mutant form of adenosine deaminase.
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PMID:Characterization of the residual adenosine deaminating activity in the spleen of a patient with combined immunodeficiency disease and adenosine deaminase deficiency. 2 16

A deficiency of adenosine deaminase in man is associated with one form of severe combined immunodeficiency disease. In an attempt to define the nature of this relationship we have characterized the normal human enzyme and examined the role of this enzyme in monocyte-macrophage activation. The human enzyme was purified 800 000-fold to apparent homogeneity from human erythrocytes with 31% recovery by immunoabsorbent chromatography. The homogeneous protein contains carbohydrate and has a subunit molecular weight of 42 000, estimated by sodium dodecyl sulphate gel electrophoresis. The enzyme was found to exist in either a soluble or a particulate form. The active soluble forms are interconvertible with apparent molecular weights of 36 000 (small), 114 000 (intermediate), and 298 000 (large). However, conversion of the small form into the large form needs a protein with a molecular weight of 200 000 which has no adenosine deaminase activity.
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PMID:Characterization of human adenosine deaminase. 2 30

Experiments over the past decade have revealed a third component in the autonomic nervous system which is neither adrenergic nor cholinergic. These nerves are strongly represented in the gastrointestinal tract of a wide range of vertebrate species and have also been identified in lung, trachea, retractor penis, bladder, oesophagus, eye, seminal vesicle and in some parts of the cardiovascular system and brain. Evidence has been presented that the principal active substance released by these nerves in the gut is a purine nucleotide, probably ATP, and they have therefore been termed 'purinergic'. The evidence includes: (1) synthesis and storage of ATP in nerves; (2) release of ATP from the nerves when they are stimulated; (3) mimicry by exogenously applied ATP of the action of nerve-released transmitter; (4) the presence of Mg2+-activated ATPase, 5'-nucleotidase and adenosine deaminase, enzymes which inactivate ATP; (5) the similar blocking and potentiating effects produced by drugs on the responses to exogenously applied ATP and nerve stimulation. A tentative model for the synthesis, storage, release and inactivation of ATP during purinergic nerve transmission is proposed. Some properties of purinergic receptors are described.
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PMID:The purinergic nerve hypothesis. 2 31


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