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)

Deficiency of red-blood-cell adenosine deaminase (R.B.C.-A.D.A.) has been reported in a proportion of patients with the autosomal recessive form of severe combined immunodeficiency (S.C.I.D.). In a family in which a child had died with S.C.I.D., R.B.C.-A.D.A. levels in the parents and other members of the family were compatible with a heterozygous state for A.D.A. deficiency. Cultured amniotic-fluid cells obtained from a subsequent pregnancy contained less than 1.5% of A.D.A. activity of normal amniotic cultures. The prenatal diagnosis of A.D.A. deficiency was confirmed at birth by the absence of A.D.A. ACTIVITY IN THE CHILD'S RED-BLOOD-CELLS. Clinical and laboratory findings in this child are similar to those of the sibling who had died with S.C.I.D.
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PMID:Adenosine-deaminase deficiency in a child diagnosed prenatally. 4 25

Deficiency of erythrocytic and lymphocytic adenosine deaminase (ADA) occurs in some patients with severe combined immunodeficiency disease (SCID). SCID with ADA deficiency is inherited as an autosomal recessive trait. ADA is markedly reduced or undetectable in affected patients (homozygotes), and approximately one-half normal levels are found in individuals heterozygous for ADA deficiency. The metabolism of purine nucleosides was studied in erythrocytes from normal individuals, four ADA-deficiency patients, and two heterozygous individuals. ADA deficiency in intake erythrocytes was confirmed by a very sensitive ammonia-liberation technique. Erythrocytic ADA activity in three heterozygous individuals (0.07,0.08, and 0.14 mumolar units/ml of packed cells) was between that of the four normal controls (0.20-0.37 mumol/ml) and the ADA-deficient patients (no activity). In vitro, adenosine was incorporated principally into IMP in the heterozygous and normal individuals but into the adenosine nucleotides in the ADa-deficient patients. Coformycin (3-beta-D-ribofuranosyl-6,7,8-trihydroimidazo[4,5-4] [1,3] diazepin-8 (R)-ol), a potent inhibitor of ADA, made possible incorporation of adenosine nucleotides in the ADA-deficient patients...
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PMID:Purine nucleoside metabolism in the erythrocytes of patients with adenosine deaminase deficiency and severe combined immunodeficiency. 94 48

Deficiency of red cell and lymphocyte adenosine deaminase (ADA) was found in children suffering from congenital combined immunologic deficiency. The parents had ADA levels intermediate between patients and controls. Complete lack of ADA activity was not found in normal subjects or in patients with a variety of other immunologic deficiency diseases.
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PMID:Adenosine deaminase deficiency in combined immunologic deficiency disease. 114 75

Inherited deficiency of the purine salvage enzyme adenosine deaminase (ADA) is responsible for approximately half the cases of autosomal recessive Severe Combined Immunodeficiency (SCID). Deficiency of ADA can also result in a much later-onset, milder immunodeficiency, while lesser degrees of enzyme deficiency can result in either late-onset immunodeficiency or grossly normal immunologic function. The full clinical spectrum of ADA deficiency is currently being more fully defined. Florid pathology is primarily restricted to the immune system and appears to result from accumulation of substrates (adenosine and deoxyadenosine) and metabolites (deoxy ATP). Studies indicate that these metabolites may preferentially accumulate in lymphoid cells and can interfere with lymphoid proliferation and function. There is evidence for several mechanisms, including induction of chromosome breaks, inhibition of ribonucleotide reductase needed for normal DNA synthesis, and inactivation of SAH hydrolase needed for normal methylation reactions. The enzyme is a 40 Kd monomer that is ubiquitous, and diagnosis can be made with many cell types including erythrocytes, lymphocytes and fibroblasts. Prenatal diagnosis has been made with chorionic villous samples, amniotic cells and fetal blood. The gene for ADA resides on the long arm of human chromosome 20, and both the expressed and structural gene have been isolated and characterized. Most patients with ADA SCID have single base pair mutations resulting in amino acid substitutions, although a splicing mutation and a deletion have been described. The treatment of choice is currently bone-marrow transplantation from a histocompatible related donor, if available. Haploidentical transplants have also been successful but appear to have higher failure rates in ADA deficients than in other types of SCID. Enzyme replacement, now using an enzyme modified to increase the half-life and decrease immunogenicity, has been reported as successful but longer-term efficacy remains to be evaluated. The disorder, despite its rarity, is for several reasons considered a prime candidate for gene therapy. Recently success has been obtained in introducing the gene into lymphoid stem cells and achieving long-term expression.
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PMID:Adenosine deaminase deficiency. 207 32

Deficiency of the purine metabolic enzyme adenosine deaminase causes severe immunodeficiency. Retroviruses have been reported to decrease the activity of adenosine deaminase, and many retroviruses, including feline leukemia virus, cause immunodeficiency. Levels of purine metabolic enzymes including adenosine deaminase and consequences of adenosine deaminase inhibition were investigated in feline leukemia virus-infected fresh tumor cells and infected and uninfected cell lines. No evidence of virus effect on levels of adenosine deaminase or other purine metabolic enzymes was detected. Neoplastic cells demonstrated considerable heterogeneity of activity levels of purine metabolic enzymes.
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PMID:Purine metabolism in feline lymphomas. 216 Nov 36

Deficiency of the enzyme adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4; ADA) leads to severe combined immunodeficiency, a disorder that potentially could be corrected by gene transfer into hematopoietic cells. We have constructed retroviruses containing human ADA cDNA and a dominant selectable marker, a mutated dihydrofolate reductase gene (DHFR*) encoding methotrexate resistance. Human ADA cDNA was inserted alone (DHFR*-ADA) or with a simian virus 40 (SV40) promoter (DHFR*-SVADA). Although NIH 3T3 cells infected with either construct produced human ADA activity, substantially greater levels were attained with DHFR*-SVADA. Infection of murine lymphoid cells in culture with DHFR*-SVADA led to expression of human enzyme at a level well above the mouse endogenous level. ADA activity was also increased after infection of a human ADA-deficient B-cell line. Lethally irradiated mice that were reconstituted with syngeneic marrow infected with the DHFR*-SVADA virus contained unrearranged, integrated proviral DNA in total spleen DNA or in spleen hematopoietic stem cell (CFU-S)-derived colonies. Nevertheless, no human ADA was detectable. RNA analysis showed relatively low and variable expression from the retroviral long terminal repeat, and no detectable expression from the internal SV40 promoter. These data suggest that intrinsic biologic differences exist between cultured cells and CFU-S in vivo.
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PMID:Retrovirus-mediated transfer of human adenosine deaminase gene sequences into cells in culture and into murine hematopoietic cells in vivo. 345 18

Adenosine deaminase is a purine salvage enzyme that catalyzes the deamination of adenosine and deoxyadenosine. Deficiency of the enzyme activity is associated with T-cell and B-cell dysfunction. Mutant adenosine deaminase has been isolated from heterozygous and homozygous deficient lymphoblast cell lines with the aid of an affinity matrix consisting of coformycin (a potent inhibitor of the enzyme) as the affinity ligand, bound to 3,3'-iminobispropylamine-derivatized Sepharose. Routinely, 80-90% of adenosine deaminase in crude cell homogenates could be bound to the material. Adenosine deaminase was specifically eluted by enzyme inhibitors or less efficiently by high substrate concentrations. Protein preparations isolated from several different deficient cell lines were highly purified and exhibited molecular weights identical to wild-type adenosine deaminase. This method produces a protein that is suitable for structural studies.
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PMID:Isolation of mutant adenosine deaminase by coformycin affinity chromatography. 349 41

The human adenosine deaminase cDNA has been cloned in a lambda-vector. Contained within a sequence of over 1500 nucleotides is an open reading frame of 1089 nucleotides that encodes the amino acids of ADA. The functional ADA gene contains at least six kilobases and has at least two introns. Using in vitro translation, molecular hybridization to ADA cDNA, and S1 nuclease mapping, ADA mRNA has been characterized in lymphoblast lines from seven different ADA-deficient children. All of the lines contain substantial amounts of RNA, which hybridizes specifically to the ADA cDNA. Four of the cell lines contain translatable mRNAs with small defects such as single base substitutions that are not detectable by S1 mapping. Deficiency of ADA activity in these lines appears secondary to synthesis of structurally altered proteins containing simple amino acid substitutions. Three of the lines contain mRNAs with S1 nuclease detectable defects. Some or all of these defective mRNAs are postulated to result from anomalous RNA processing. In these cases the causes of the ADA deficiency may be more complex than simple amino acid substitutions in the protein and could include small insertions or deletions of amino acids as well as changes in the efficiency of translation of the mRNAs.
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PMID:Molecular biology of the adenosine deaminase gene and messenger RNA. 386 73

Deficiency of either one of the subsequent purine catabolic enzymes adenosine deaminase or purine nucleoside phosphorylase results in immunodeficiency disease in humans. However, the mechanism by which impairment of purine metabolism may cause immunodeficiency is unclear. In the present work we have studied the catabolism of purine ribonucleotides and deoxyribonucleotides in T lymphocytes to better understand the role of purine nucleoside phosphorylase and adenosine deaminase in the immune function. It was found that purine deoxyribonucleotides are degraded via catabolic pathways distinctly different from those used for purine ribonucleotide degradation. Thus both adenine and guanine ribonucleotides are deaminated to IMP whereas purine deoxyribonucleotides are exclusively dephosphorylated to the corresponding deoxyribonucleosides. These findings may explain the relatively higher degradation rates of purine deoxyribonucleotides in mammalian cells as compared to purine ribonucleotides. The catabolism of purine nucleotides is tightly linked to the active purine nucleoside cycles which consist of the phosphorolysis of purine nucleosides and deoxyribonucleosides to their corresponding bases, their salvage to monophosphates and back to the corresponding ribonucleosides. The above observations also imply that a possible role of the purine nucleoside cycles is to convert purine deoxyribonucleotides into their corresponding ribonucleotide derivatives. Deficiencies of purine nucleoside phosphorylase or of adenosine deaminase activities, enzymes which participate or lead to the purine nucleoside cycles, thus result in a selective impaired deoxyribonucleotide catabolism and immunodeficiency.
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PMID:Catabolic pathways of purine ribonucleotides and deoxyribonucleotides in lymphocytes. 387 1

Deficiency of the purine salvage enzymes purine nucleoside phosphorylase (PNP) and adenosine deaminase (ADA) are known causes of immunodeficiency. Evidence for inhibition of these enzymes was sought in 16 patients on azathioprine therapy by testing for deoxyguanosine (PNP deficiency) and deoxyadenosine (ADA deficiency) in urine using a novel phosphorescence method. These abnormal nucleosides were not found in urine of azathioprine treated patients or in 30 normal controls but were easily detected in urine from proven cases of PNP and ADA deficiency suggesting lack of in vivo inhibition of PNP and ADA by azathioprine.
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PMID:Lack of inhibition of purine nucleoside phosphorylase and adenosine deaminase in patients treated with azathioprine. 391 49


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