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)

Mice were given constant infusions of the adenosine deaminase inhibitor, 2'-deoxycoformycin, by i.p. implantation of microosmotic pumps, delivering the compound at a rate of 0.16 mg hr-1 kg-1. In accordance with published data, we observed that adenosine deaminase in most tissues was nearly completely inhibited. In addition, the S-adenosylhomocysteine hydrolase activity decreased slowly and showed a half-life in liver of about 4 hr. The rate and extent of the inactivation were highest in spleen. The amounts of adenosine, 2'-deoxyadenosine, S-adenosylhomocysteine, and S-adenosylmethionine were determined in treated animals and control animals. The tissue levels of adenosine and, to a lesser degree, S-adenosylhomocysteine and S-adenosylmethionine were critically dependent on the procedure used for processing the tissues. Lowest concentrations were observed when the organs were frozen in situ by liquid nitrogen. Treatment with 2'-deoxycoformycin induced no or a moderate increase in tissue content of adenosine and S-adenosylhomocysteine, whereas the amount of 2'-deoxyadenosine increased markedly, especially in spleen and thymus. 2'-Deoxycoformycin treatment caused an increase in adenosine and 2'-deoxyadenosine, but not S-adenosylhomocysteine, in serum of mice.
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PMID:Effect of 2'-deoxycoformycin infusion on S-adenosylhomocysteine hydrolase and the amount of S-adenosylhomocysteine and related compounds in tissues of mice. 660 64

The tight-binding adenosine deaminase inhibitor, 2'-deoxycoformycin (dCF), was continuously infused into mice by intraperitoneal implantation of microosmotic pumps delivering the compound at a rate of 0.16 mg hr-1 kg-1 for up to 6 days. The activity of cerebral adenosine deaminase was nearly totally inhibited. The amount of adenosine and 2'-deoxyadenosine was determined in the brain frozen in liquid nitrogen through the intact skull bone. The concentration of adenosine was about 1 nmol/g, and was essentially not altered following treatment with deoxycoformycin. Deoxycoformycin induced a progressive increase in cerebral content of 2'-deoxyadenosine, which after 1 day of treatment equalled the amount of adenosine. The concentrations of serotonin, dopamine and noradrenaline in the brain were not altered.
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PMID:Neurotoxicity of deoxycoformycin: effect of constant infusion on adenosine deaminase, adenosine, 2'-deoxyadenosine and monoamines in the mouse brain. 660 84

Structural analogues of erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), in which the adenine moiety of the molecule was modified, were prepared in order to investigate the structural requirement of EHNA as an inhibitor of adenosine deaminase (ADA). Thus, 1- and 3-deaza-EHNA and their 6-deamino analogues were synthesized and evaluated as inhibitors of ADA from calf intestine. Inhibition studies indicated that isosteric substitution of pyrimidine nitrogens by carbons could be tolerated at the enzymatic binding site. In fact, 3-deaza-EHNA was found to have an inhibitory activity comparable to EHNA itself, and 1-deaza-EHNA, though less potent, is a good inhibitor. The 6-amino group gives an important contribution to the enzymatic binding if the N1 nitrogen is also present, conferring on the compound the characteristic of a semitight inhibitor.
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PMID:Adenosine deaminase inhibitors. Synthesis of deaza analogues of erythro-9-(2-hydroxy-3-nonyl)adenine. 669 73

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

Deaza analogs of adenosine, where carbon substitutes for nitrogen, are not substrates for adenosine deaminase (adenosine aminohydrolase EC 3.5.4.4); little is reported on their ability to be inhibitors. Among the deaza analogs of adenosine and purine riboside that we have been testing, 1-deazaadenosine proved to be the best inhibitor (Ki = 6.6 X 10(-7)M). 1-deazapurine riboside, 1,3-dedeazadenosine, 3-deazaadenosine have affinity by about two and three order of magnitude lower.
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PMID:Inhibition of adenosine deaminase by deaza derivatives of adenosine and purine riboside. 718 3

The adenylate deaminase activity of liver, kidneys, brain, striated muscle, stomach, intestine, skin and adipose tissue of fed and 24 hours fasted rats has been studied. The level of activity of the enzyme in muscle is at least an order of magnitude higher than in other organs. Fasting induced a significant increase in the muscle adenylate deaminase activity, while in kidneys, skin, small intestine, liver and adipose tissue, significant decreases were observed and practically no changes were found in brain and stomach. The possible incidence of these changes upon the overall alpha-amino nitrogen economy of the fasted animals is discussed.
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PMID:Adenylate deaminase activity in the rat. Effect of 24 hours of fasting. 726 24

A series of 1-deazaadenine nucleosides with the N6 nitrogen unsubstituted or bearing methyl or cycloalkyl substituents, with or without a chloro group in the 2-position, and with the glycosylic moiety being ribose (1-16), 2'-deoxyribose (17-32), or 2', 3'-dideoxyribose (33-48) were designed and synthesized starting from 5,7-dichloro-3H-imidazo[4,5-b] pyridine (50). These compounds were evaluated for their in vitro activity against human immunodeficiency virus type-1 (HIV-1) and herpes simplex virus type-1 (HSV-1). In addition they were tested for their ability to inhibit adenosine deaminase (ADA) from calf intestine. While the parent compounds 1-deazaadenosine (9), 2'-deoxy-1-deazaadenosine (25), and 2',3'-dideoxy-1- deazaadenosine (41) and the corresponding 2-chloro derivatives were inactive, nucleosides bearing cycloalkyl substituents on N6 exhibited moderate to good anti-HIV-1 activity, compared to 2',3'-dideoxyadenosine, with the degree and pattern of improvement depending on the structure of the sugar moiety. In general, 2'-deoxy- and 2',3'-dideoxy derivatives were more potent compounds than the corresponding ribose nucleosides. Compounds bearing a 6-cycloheptyl or cyclooctylamine were the most active in every series. The presence of a chloro group in the 2-position improved both activity and therapeutic index in every series, the most active compound being 2'-deoxy-2-chloro-N6-cycloheptyl-1-deazaadenosine (23; ED50 = 0.2 microM). On the other hand, most of these derivatives were inactive as anti-HSV-1 agents, showing a high degree of virus selectivity. The 1-deazaadenine derivatives were not substrates of adenosine deaminase, and some of them proved to be good inhibitors of the enzyme. However, the ADA inhibitory activity does not account for the antiviral potency since increased lipophilicity and steric hindrance of substituents resulted in derivatives much less active than the parent compounds.
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PMID:Synthesis and biological evaluation of N6-cycloalkyl derivatives of 1-deazaadenine nucleosides: a new class of anti-human immunodeficiency virus agents. 756 37

2-Chlorodeoxyadenosine (2-CDA) is an adenosine deaminase resistant analogue of deoxyadenosine which has shown clinical activity in human hematologic neoplasms. The exact mode of action of this drug remains the subject of investigation. We applied the Differential Staining Cytotoxicity (DiSC) assay to 50 human tumour specimens obtained from patients with a variety of hematologic malignancies to characterise the activity spectrum of 2-CDA. We evaluated the disease-specific activity of this agent in vitro and compared its relative cytotoxicity with that of other antineoplastic agents in current clinical use. Comparisons were conducted against nitrogen mustard, doxorubicin, vincristine and cytosine arabinoside. Our results indicate that 2-CDA has activity in myeloid and many lymphoid neoplasms but that multiple myeloma specimens reveal significant resistance. Cross resistance studies reveal a correlation between 2-CDA and the alkylator nitrogen mustard but no correlation between 2-CDA and doxorubicin, vincristine nor cytosine arabinoside. The results suggest 2-CDA activity in many human hematologic neoplasms with the clear exception of multiple myeloma and further suggest a relationship between this agent and alkylators of the mustard class. The DiSC assay may provide useful insights in the pre-clinical evaluation of new antineoplastic drugs and may help to elucidate drug activities and mechanisms of action.
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PMID:2 chlorodeoxyadenosine activity and cross resistance patterns in primary cultures of human hematologic neoplasms. 809 2

A series of erythro-1-(2-hydroxy-3-nonyl)azole derivatives have been synthesized and evaluated for adenosine deaminase (ADA) inhibitory activity, in order to introduce simplifications in the ADA inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA, 1a). The synthesis of most of the reported compounds was achieved by reaction of 2-bromo-3-nonanone with the suitable azole followed by reduction of the carbonyl group to give a diastereoisomeric mixture of N-substituted (2-hydroxy-3-nonyl)azoles. Separation of diastereoisomers was achieved by HPLC or by preparative TLC plates. The results of the enzymatic test indicate that the nitrogen in the 3-position, and secondly, the nitrogen in the 5-position are very important for the interaction of the azole ring with the inhibitory site on the enzyme. In fact, the pyrazole and the 2-substituted 1,2,3-triazole derivatives (10 and 15, respectively) are nearly inactive, whereas the erythro-1-(2- hydroxy-3-nonyl)-1,2,4-triazole (18e) was the most potent ADA inhibitor in the series with Ki = 0.3 microM.
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PMID:Adenosine deaminase inhibitors: synthesis and structure-activity relationships of 2-hydroxy-3-nonyl derivatives of azoles. 828 97

We have solved the structure of Escherichia coli cytidine deaminase (CDA) complexed to the transition state analog, 5-fluoroprimidin-2-one riboside. The monomer of the alpha 2 CDA dimer is composed of a small N-terminal alpha-helical domain with no obvious connection to the active sites, and two, larger, core domains. The two core domains have nearly identical tertiary structures and are related by approximate 2-fold symmetry, but lack internal amino acid sequence homology. Comparison of the core domain structure with known structures by sequence homology and structural compatibility searches suggests that the CDA tertiary structure cannot be superimposed on any known protein structure. The two active sites per dimer are formed across the subunit interface. The N-terminal core domain provides a pyrimidine nucleoside and zinc-binding pocket and the structurally homologous C-terminal core domain in the other monomer covers this active-site cleft, completely sequestering the ligand from solvent. The deeply buried zinc-binding site is formed by a novel "topological switch point" at the amino termini of two alpha-helices in consecutive alpha-beta-alpha-beta segments. The transition state analog is bound as a covalent hydrate at C4. The inhibitor hydroxyl oxygen atom interacts both with the zinc atom and the Glu104 carboxylate group, affording high differential affinity for the hydroxyl group relative to a hydrogen atom, in a manner reminiscent of that observed in adenosine deaminase (ADA). Unlike the latter enzyme, the zinc atom is coordinated in a tetrahedral ligand field to two cysteine and one histidine ligands, plus the hydroxyl group. Moreover, the inhibitor stereochemistry is of the opposite hand from that of the corresponding ADA inhibitor at C4(R), but is the same at the hydroxyl group O4(S). A consequence of these stereochemical differences is that in CDA a single conserved carboxylate side-chain, Glu104, can provide all of the necessary proton transfer functions involved in generating the zinc hydroxide nucleophile, and protonating the pyrimidine ring nitrogen atom and leaving amino group. The differences in zinc ligands, ligand-binding stereochemistry, and tertiary structures of CDA and ADA strongly suggest that the common features of transition state stabilization arose by convergent evolution.
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PMID:Cytidine deaminase. The 2.3 A crystal structure of an enzyme: transition-state analog complex. 828 86


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