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)

The activities of alanine, aspartate and branched-chain amino acid transaminases, glutamate dehydrogenase, glutamine synthetase and adenylate deaminase have been studied in liver of male rats exposed [12 hours at 4 degrees C] or acclimated [15 days at 4 degrees C] to cold temperature. Cold temperature induced an increase of the activities of glutamate dehydrogenase and alanine and aspartate transaminases both in cold-exposed and cold-acclimated animals; adenylate deaminase activity diminished after 15-day cold acclimation. There were not significant changes induced by cold temperature in the activities of the other two enzymes studied. These results agree with a possible direct implication of amino acid utilization by the liver in the context of the overall thermogenic response to cold temperature.
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PMID:Influence of cold exposure on liver amino acid metabolism enzymes of the rat. 290 59

The enzymatic inosine 5'-monophosphate assay described by Grassl [in, Methods of Enzymatic Analysis (H. U. Bergman, ed.), pp. 2168-2171, Academic Press, New York (1974)] is highly nonspecific, as ITP, ATP, ADP, AMP, and adenosine react stoichiometrically. The reactivity with the adenine derivatives is due to the tri- and diphosphatase activity of alkaline phosphatase (AP), coupled with adenosine deaminase (and possibly AMP deaminase) contamination of commercially available preparations of AP, purine-nucleoside phosphorylase, and/or xanthine oxidase. The inclusion of coformycin (0.05 microgram/ml), a potent inhibitor of these deaminases, completely eliminated the cross-reactivity. ITP, however, still reacted stoichiometrically due to the tri- and diphosphatase activity of AP. Meyer and Terjung [Amer. J. Physiol. 237 C111-C118 (1979)] introduced a modification of Grassl's procedure, substituting 5'-nucleotidase for AP. It has been found that this disallows reactivity with ATP, ADP, and ITP but that AMP and adenosine still react completely. Coformycin prevents this cross-reactivity. It is therefore recommended that the assay be carried out with 5'-nucleotidase (instead of AP) and coformycin, in order to achieve a more specific assay, and one more suitable for use with whole tissue extracts.
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PMID:An enzymatic inosine 5'-monophosphate assay of increased specificity. 298 81

A microassay requiring as few as 2 X 10(5) cells per assay was developed for systematic analysis of 9 purine enzymes in lymphocytes from equine peripheral blood, spleen, lymph node, thymus and bone marrow. The activities of adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), adenosine kinase (AK), deoxyadenosine kinase (dAK), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-N), AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase (HGPRT or HPRT), and adenine phosphoribosyl transferase (APRT) were measured by this microassay in lymphocytes from peripheral blood from four different breeds of horses (Arabian, Quarter Horse, Thoroughbred and Shetland Pony). There were no significant differences in the enzyme activities among the various breeds. Peripheral blood lymphocytes (PBL) from foals exhibited enzyme activities similar to those observed for adult animals. All lymphoid tissue contained similar levels of activity for each kinase (AK, dAK and dCK). Spleen had the highest activity for ADA, PNP, 5'-N, and HGPRT. The lowest activity for ADA, APRT, PNP and AMP deaminase was found in thymus. Enzymatic activities that varied the most among the tissue were 5'-N, ADA, APRT, HGPRT and AMP deaminase.
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PMID:Distribution of enzymes of purine metabolism in lymphocytes of horse, Equus caballus. 299 Aug 11

Under conditions where 2'-deoxycoformycin is enzymatically phosphorylated by wheat shoot phosphotransferase to the 5'-phosphate in 15-20% yield, coformycin is a relatively poor substrate, and is phosphorylated only to the extent of less than or equal to 5%. However, chemical phosphorylation of coformycin by modifications of the Yoshikawa procedure led to isolation of coformycin-5'-phosphate in 20% overall yield. Coformycin-5'-phosphate was characterized by various criteria, including 1H NMR spectroscopy. Comparison of the spectrum with that of the parent nucleoside indicated that the nucleotide is predominantly, although not exclusively, in the conformation anti about the glycosidic bond. Like 2'-deoxycoformycin-5'-phosphate, coformycin-5'-phosphate was a feeble substrate of snake venom 5'-nucleotidase, and is hydrolyzed, quantitatively, at only 2% the rate for 5'-AMP. With 5'-AMP analogues as substrate, the 5'-phosphates of both coformycin and deoxycoformycin were poor inhibitors of the enzyme, with Ki values greater than 0.3 mM. The 5'-phosphates of both coformycin and deoxycoformycin do not significantly inhibit adenosine deaminase (Ki greater than 0.2 mM), but are potent inhibitors of adenylate deaminase (Ki less than or equal to 10(-9) M). Neither coformycin nor deoxycoformycin are inhibitors of mammalian purine nucleoside phosphorylase. The stabilities of coformycin, deoxycoformycin, and their 5'-phosphates, have been examined as a function of pH, and nature of the buffer medium. In particular, all exhibit instability in acid and neutral media, but are relatively stable in the vicinity of pH 9. Some biological aspects of the overall results are presented.
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PMID:Phosphorylation of coformycin and 2'-deoxycoformycin, and substrate and inhibitor properties of the nucleosides and nucleotides in several enzyme systems. 300 59

The activity of 5'-nucleotidase, AMP deaminase, adenosine deaminase, acid phosphatase, alkaline phosphatase and nucleotide pyrophosphatase was assayed in human thyroid glands. The 5'-nucleotidase activity was higher than that of AMP deaminase which suggested that AMP undergoes degradation primarily as a result of dephosphorylation in thyroid tissue. A high acid phosphatase activity was noted as compared to that of alkaline phosphatase activity. In toxic goitre the increase in adenosine deaminase and acid phosphatase was observed together with the decrease in pyrophosphatase activity.
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PMID:Activity of 5'-nucleotidase, AMP deaminase, adenosine deaminase, acid and alkaline phosphatase and nucleotide pyrophosphatase in human thyroid. 300 51

Activities of adenylate-degrading enzymes in muscles of vertebrates and invertebrates were determined. Mammalian and fish muscles showed a markedly higher activity of AMP deaminase with a lower level of adenosine deaminase and 5'-nucleotidase. Cephalopods showed an active adenosine deaminase and a 5'-nucleotidase which preferred AMP as the substrate. Negligible deamination of AMP and adenosine and little phosphohydrolase activity toward AMP and IMP were observed in the shellfish muscles. Adenine nucleotides can be degraded to form IMP via the AMP deaminase reaction in vertebrate muscles, while dephosphorylation of AMP to adenosine, which is then converted to inosine, appears to proceed in cephalopods. Adenylates can be hardly degraded in shellfish muscles.
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PMID:Activities of adenylate-degrading enzymes in muscles from vertebrates and invertebrates. 303 Jun 25

In a previous study of three independent families of mutants selected for overproduction of adenylate deaminase (AMPD), we were not able to isolate a cDNA probe for the gene and so could not demonstrate its amplification directly. In addition to overproduction of AMPD, four proteins of unknown function, designated W, X, Y1, and Y2, accumulated, and by using the corresponding cDNA probes, we demonstrated amplification of all four genes. In independent mutant clones, sometimes all and sometimes only a subset of these genes were amplified. Assuming that all five genes are linked, the pattern of their coamplification suggested a genetic map in which AMPD lies between W and Y1. We show here that a two-step chromosome walk joins the W and Y1 genes, that the AMPD gene is the only expressed sequence between them, and that its amplification is indeed responsible for overproduction of the AMPD protein. In the course of this work, we cloned and studied two novel joints which mark rearrangements on either side of the AMPD gene. Each joint was generated independently in a single first-step mutant at single or low copy number. Remarkably, each joint was amplified preferentially in every second- and third-step mutant derived from the first-step line in which it was originally present, suggesting that the two independent rearrangements each generated amplification-prone structures.
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PMID:Preferential amplification of rearranged sequences near amplified adenylate deaminase genes. 333 58

High-performance liquid chromatography analysis of acid-extracted tissues revealed decreases of high-energy nucleotides and increases in low-energy nucleotides and metabolites in heart, diaphragm, and liver but not in kidneys of diabetic rats. In comparison with nondiabetic rats, the total adenine nucleotide content of diabetic rat heart and diaphragm but not liver decreased, indicating an increase in catabolism of AMP. Maximal initial rates of the AMP catabolic enzymes 5'-nucleotidase, adenosine deaminase, and AMP deaminase were elevated in the hearts of BB/Wistar and streptozocin-induced diabetic rats. Nucleotide salvage enzymes adenylosuccinate synthetase and adenylosuccinate lyase were elevated above normal in the diabetic heart, whereas hypoxanthine-guanine phosphoribosyl transferase was not altered. Cytosolic-to-mitochondrial ratios from maximal initial rates after correction for mitochondrial breakage were increased above controls in diabetic hearts for nucleoside diphosphokinase and aspartate aminotransferase. Nucleotide levels, degradation rates, and substrate compartmentation between cytosol and mitochondria are discussed in relation to concurrent diabetes.
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PMID:Adenine nucleotide metabolism in hearts of diabetic rats. Comparison to diaphragm, liver, and kidney. 336 Feb 19

The amplified DNA of HC50474, a Chinese hamster fibroblast cell line selected in three steps for high resistance to coformycin, consists chiefly of 150 copies of a large inverted duplication including the adenylate deaminase gene. Most if not all of these units are more than 2 x 120 kb long. The inverted duplication was first detected in the cells recovered from the second selection step, at the same chromosomal location as the first step amplified units. Its formation and amplification appear to be coupled since the second step cell line already contained 40 copies of this novel structure. Reamplification of the inverted duplication occurred at the third step of selection concomitant with the loss of amplified DNA acquired during the first step. The head-to-head junction has been formed by recombination within a recombinational hotspot described previously [Hyrien, O., Debatisse, M., Buttin, G. and Robert de Saint Vincent, B. (1987) EMBO J., 6, 2401-2408]. Sequences at the joint and in the corresponding wild-type region reveal that the crossover sites, one of which occurs in the putative promoter region of B2 repeat, are located at the top of significant stem-loop structures and that patchy homologies between the parental molecules on one side of the breakpoints allow alignment of these crossover sites. We present a model which explains the formation and amplification of this and other large inverted duplications by errors in DNA replication.
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PMID:The multicopy appearance of a large inverted duplication and the sequence at the inversion joint suggest a new model for gene amplification. 336 18

Long-term bovine lymphocyte cultures were initiated by stimulation with alloantigens and maintained in continuous culture using medium containing recombinant human interleukin-2 (rh IL-2). The development of specific and lectin-dependent killing was monitored following primary alloantigen challenge. Cytolytic activity was barely detectable after 7 days of culture, but gradually increased with peak activity occurring after 21 days of culture. A panel of monoclonal antibodies (MoAb) was used to determine whether a shift in the antigen phenotype of the cell population occurred during culture. The primary cell type that grew in culture was of the T-cell lineage with minimal or no expression of class II antigens. The activities of adenosine deaminase (ADA), purine nucleotide phosphorylase (PNP), adenosine kinase (AK), deoxyadenosine kinase (dAK), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-N), AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase (HGPRT or HPRT), and adenine phosphoribosyl transferase (APRT) were measured by microassay in resting peripheral blood lymphocytes (PBL) and in cells from long-term cultures. Large increases in the activities of PNP and HPRT with a decrease in the activity of ADA were observed. The data show that long-term cultures of lymphocytes can be readily generated, and that sequential changes in antigenic phenotype and function can be monitored and correlated with quantitative changes in enzyme activity.
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PMID:Development and maintenance of bovine cytotoxic lymphocytes with recombinant human interleukin-2. 348 20


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