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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deoxycytidylate (DCMP) deaminase was assayed at various times during and after normal and abnormal pregnancies. The level in amniotic fluid was assessed at induction and at caesarean section, and cord blood levels were estimated after normal delivery and at caesarean section. A rise occurred during labour and after hysterectomy and caesarean section--returning to normal after 2-3, and 12 days respectively. Levels above 4.8 X 10-minus 4 ml-minus 1 were found in cases of preeclamptic toxaemia and early intrauterine death and in twin pregnancies over 36 weeks' gestation. It is suggested that because of its low incidence of false-negative and false-positive results this test is far superior to other enzyme tests in pregnancy, and a further trial is in progress to assess its role.
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PMID:Deoxycytidylate deaminase in pregnancy. 113 71

Cytosol thymidine kinase (TK) and deoxycytidylate (dCMP) deaminase formation was investigated in synchronized cultures of K12 Chinese hamster cells which have a temperature-sensitive lesion affecting the initiation of DNA synthesis. Enzyme formation was found to be cycloheximide-sensitive and also temperature-dependent. Beginning at about six hours after addition of medium with 10% calf serum to serum-depleted K12 cultures, cytosol TK and dCMP deaminase activities increased when the cultures were incubated at 36.5 degrees but not at 40.5 degrees. When cultures were shifted from 36.5 degrees to 40.5 degrees at 4,6, or 8 hours after serum addition, TK activity continued to increase, though not to the level observed at ten hours in cultures maintained at 36.5 degrees. Actinomycin D addition at the time of serum reversal or four hours later blocked the TK increase normally observed at the permissive temperature at ten hours. However, when actinomycin D addition was delayed for six or eight hours after serum addition, the increase in TK measured at ten hours resembled that observed in the temperature shift-up experiments. The results provide evidence that the mutation in K12 Chinese hamster cells most likely blocks the progression through G1 into S and suggest that transcription or post-transcriptional processing required for TK formation is affected.
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PMID:Formation of thymidine kinase and deoxycytidylate deaminase in synchronized cultures of chinese hamster cells temperature-sensitive for DNA synthesis. 126 6

The Bacillus subtilis small cytoplasmic RNA (scRNA) is the structural homologue of both the RNA component of the eukaryotic signal recognition particle (SRP) and the Escherichia coli 4.5S RNA, and it can complement the essential function of the latter RNA in vivo. In the course of characterization of the single-copy scRNA gene locus (scr) we identified an open reading frame, termed ORF17, upstream from scr that encodes an acidic 17 kDa protein of unknown function. This analysis involved DNA sequencing, monitoring expression of transcriptional and translational ORF17-cat and ORF17-lacZ fusions, respectively, and purification and sequencing of the ORF17-lacZ fusion protein. Apparently, transcription of ORF17 proceeds into scr. A small portion of the 17 kDa protein shows homology to deoxycytidylate (DCMP) deaminase of bacteriophagphage T2, but no similarity exists to the sequenced SRP-polypeptides or any other known protein sequences.
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PMID:Characterization of a 17 kDa protein gene upstream from the small cytoplasmic RNA gene of Bacillus subtilis. 169 58

The activities of orotate phosphoribosyltransferase (OPRT), cytidine triphosphate (CTP) synthetase, deoxycytidine monophosphate (dCMP) deaminase, thymidine monophosphate (dTMP) kinase, uridine (Urd) kinase, thymidine (dThd) kinase, Urd and dThd phosphorylases, and DNA polymerase were examined in the eight human lung squamous cell carcinomas and five lung adenocarcinomas, and five tumor-adjacent normal lung tissues. All of these enzymes are involved in pyrimidine nucleotide synthesis. The metabolism of 5-fluorouracil (5-FU) was determined. The levels of these enzymes, except for OPRT, were high in tumor tissues and almost the same between lung squamous cell carcinomas and adenocarcinomas, with no statistical difference. The activities for phosphorylation and degradation of 5-FU were similar in each tissue type of tumor. As 5-FU is incorporated into tumor cells and is metabolized actively to 5-FU nucleotides in squamous cell carcinoma tissues, at almost the same level seen in adenocarcinoma tissues, this drug should have a wide clinical application.
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PMID:Comparison of pyrimidine nucleotide synthetic enzymes involved in 5-fluorouracil metabolism between human adenocarcinomas and squamous cell carcinomas. 216 41

Though data from cell lines are abundant, the reason for the development of resistance to 1-beta-D arabinofuranosylcytosine (ara-C) in vivo remains unresolved. A broad interpatient variation of metabolic parameters has further complicated interpretation of the results. The present study compares ara-C metabolism in leukemic blasts of two patients with newly diagnosed disease, before and after repeated treatment with ara-C containing chemotherapy regimens in vivo. Membrane transport of ara-C was unchanged after treatment. In addition, cell-free extracts of blasts obtained after treatment failure showed an unchanged cytidine deaminase activity. Though deoxycytidine kinase activity in cell extracts was unaltered or increased after treatment failure, the activity in situ, measured as the rate of 1-beta-D-arabinofuranosylcytosine triphosphate (ara-CTP) formation, was decreased. This could be shown to be due to an expansion of the deoxycytidine triphosphate (dCTP) pool. The severalfold increase in dCTP pool was accompanied by a decrease in thymidine triphosphate (dTTP) pool and correlated with a decrease in deoxycytidylate deaminase (dCMP-deaminase) activity in cell free extracts. Low dCMP-deaminase activity had been shown to confer an ara-C resistant phenotype to cell lines in vitro. Data presented in this paper show that a selection for leukemic blasts with low dCMP-deaminase activity can also be favored by ara-C containing treatment regimens in vivo. Our data suggest that this mechanism might contribute to treatment failure.
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PMID:Concordant changes of pyrimidine metabolism in blasts of two cases of acute myeloid leukemia after repeated treatment with ara-C in vivo. 223 89

In tissues obtained from patients undergoing gastrectomy, the activities of 12 enzymes involved in pyrimidine nucleotide synthesis: cytidine triphosphate (CTP) synthetase, deoxycytidine monophosphate (dCMP) deaminase, thymidine monophosphate (dTMP) kinase, uridine (Urd), deoxycytidine (dCyd) and thymidine (dThd) kinases, Urd, deoxyuridine (dUrd) and dThd phosphorylases, cytidine (Cyd) and dCyd deaminases, and DNA polymerase were examined in the eight-well-differentiated and 12 poorly differentiated gastric cancer tissues and the ten normal tissues. These cases were clinically advanced and serosal invasions were evident. Activities of these enzymes were higher in the poorly differentiated tissues than the well differentiated type and in the normal tissues. Significant differences were noted between the poorly differentiated and well-differentiated types, in dTMP kinase (P less than 0.02), dThd kinase (P less than 0.05), dThd phosphorylase (P less than 0.01), and DNA polymerase (P less than 0.05). The authors' findings show that the level of pyrimidine nucleotide synthesis, in both de novo and salvage pathways, is higher in the poorly differentiated gastric cancer tissues than in the well-differentiated type and suggest that antitumor drugs have an increased susceptibility in cases of poorly differentiated gastric carcinoma.
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PMID:Pyrimidine nucleotide synthesis is more extensive in poorly differentiated than in well-differentiated human gastric carcinoma. 291 Apr 29

The complement-fixing tumor (T) antigen induced by simian virus 40 (SV40) has been prepared from SV40-infected cell cultures, from infected cell cultures treated at the time of infection with 1-beta-d-arabinofuranosylcytosine (ara-C), and from SV40-transformed cells. Upon partial purification, the T antigen exhibited the following properties: it was tightly adsorbed by calcium phosphate gel, it was precipitated by acetic acid at pH 5 or by ammonium sulfate at about 20 to 32% saturation, and it had a molecular weight greater than 250,000, as estimated by Sephadex G-200 gel chromatography. In contrast, deoxycytidylate (dCMP) deaminase, thymidylate (dTMP) kinase, and thymidine (dT) kinase were less strongly bound to calcium phosphate and were not precipitated at pH 5; these enzymes also had much lower molecular weights than the T antigen, as did dihydrofolic (FH(2)) reductase. Furthermore, higher ammonium sulfate concentrations were required to precipitate dCMP deaminase, dTMP kinase, and FH(2) reductase activities than to precipitate the T antigen. Another difference was that the T antigen was not stabilized, but dCMP deaminase, dTMP kinase, and dT kinase, were stabilized, respectively, by dCTP, dTMP, and dT or dTTP. Deoxyribonucleic acid (DNA) polymerase activity resembled the T antigen in adsorption to calcium phosphate, in precipitation by ammonium sulfate or at pH 5, and in the rate of inactivation when incubated at 38 C. However, the polymerase activity could be partly separated from the T antigen by Sephadex G-200 gel chromatography. The cell fraction containing partially purified T antigen also contained a soluble complement-fixing antigen (presumably a subunit of the viral capsid) which reacted with hyperimmune monkey sera. The latter antigen was present in very low titers or absent from cell extracts prepared from SV40-infected monkey kidney cell cultures which had been treated with ara-C at the time of infection, or from SV40-transformed mouse kidney (mKS) or hamster tumor (H-50) cells. The T antigen, however, was present in usual amounts in SV40-transformed cells or ara-C treated, infected cells.
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PMID:Nonidentiy of some simian virus 40-induced enzymes with tumor antigen. 431 27

The activities of dCMP deaminase and DNA polymerase I increased twofold and fivefold in BHK-21/C13 cells after infection by the virus of herpes simplex. The increases were greatly diminished, and under certain conditions prevented, by inclusion of actinomycin D or cycloheximide in the cell-virus system during the infective cycle. The dCMP deaminase purified from infected cells harvested 8h after infection differed from the deaminase purified from non-infected cells inasmuch as (a) it was more resistant to heating at 37 degrees C; (b) the substrate (dCMP) concentration at half-maximum velocity was lower; (c) maximum activation was achieved by a lower concentration of dCTP; (d) it was more resistant to inhibition by dTTP; and (e) it behaved differently when assayed in the presence of a herpes-virus-specific antiserum. The DNA polymerase activity in the infected cells was markedly decreased in the presence of the herpes-virus-specific antiserum.
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PMID:Deoxycytidylate deaminase evidence for a new enzyme in cells infected by the virus of herpes simplex. 437 45

dCMP deaminase was partially purified from BHK-21/C13 cells grown in culture. The molecular weight of the enzyme was estimated by gel filtration and gradient centrifugation to be 130000 and 115000 respectively. The enzyme had a pH optimum of 8.4. Its activity versus substrate concentration curve was sigmoid, the substrate concentration at half-maximal velocity being 4.4mm. dCTP activated the deaminase maximally at 40mum, gave a hyperbolic curve for activity versus dCMP concentration and a K(m) value for dCMP of 0.91mm. dCTP activation required the presence of Mg(2+) or Mn(2+) ions. dTTP inhibited the deaminase maximally at 15mum; the inhibition required the presence of Mg(2+) or Mn(2+) ions. The enzyme was very heat-labile but could be markedly stabilized by dCTP at 0.125mm and ethylene glycol at 20% (v/v).
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PMID:Deoxycytidylate deaminase. Properties of the enzyme from cultured kidney cells of baby hamster. 445 1

The role of deoxyribonucleic acid (DNA) replication in the control of the synthesis of deoxycytidylate (dCMP) deaminase and lysozyme in Bacillus subtilis infected with bacteriophage 2C has been studied. These phage-induced enzymes are synthesized at different times during the latent period. It was shown by actinomycin inhibition that the formation of the late enzyme (lysozyme) required messenger ribonucleic acid (mRNA) synthesized de novo after the initiation of translation of mRNA which specifies the early function (dCMP deaminase). The inhibition of phage DNA synthesis by mitomycin C prevented the synthesis of lysozyme only when added before the onset of phage DNA replication, but it did not affect the synthesis or action of dCMP deaminase when added at any time during the latent period. Treatment of infected cells with mitomycin C after phage DNA synthesis had reached 8 to 10% of its maximal rate resulted in the production of normal amounts of lysozyme. These observations suggest that mRNA specifying early enzymes can be transcribed from parental (and probably also from progeny) DNA, whereas late functional messengers can be transcribed only after the formation of progeny DNA.
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PMID:Deoxyribonucleic acid replication and expression of early and late bacteriophage functions in Bacillus subtilis. 499 39


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