Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3'-Fluoro-2',3'-dideoxythymidine 5'-(alpha-methylphosphonyl)-beta,gamma- diphosphate and 2'-deoxythymidine-5'-(alpha-methylphosphonyl)-beta, gamma- diphosphate have been synthesized. Both compounds are incorporated into DNA chains during catalysis by reverse transcriptases of human immunodeficiency (HIV) and avian myeloblastosis (AMV) viruses, DNA polymerase beta from rat liver, terminal deoxynucleotidyl transferase from calf thymus and (at a very low rate) is by E. coli DNA polymerase I, Klenow fragment. The first compound is a termination substrate while the second is capable of multiple incorporation into the DNA chains. For instance, reverse transcriptase catalysis resulted in the appearance of 8 residues of second compound. DNA polymerases alpha and epsilon from human placenta incorporated none of the above compounds into DNA chains, although an inhibition of DNA synthesis by both compounds was observed with all enzymes mentioned. The 3'----5'-exonuclease activity of DNA polymerase I, Klenow fragment, hydrolyzed DNA fragments containing phosphonomethyl internucleoside groups, while such DNA fragments were resistant to the E. coli exonuclease III.
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PMID:Formation of phosphonester bonds catalyzed by DNA polymerase. 137 65

The DNA synthesizing subunit (alpha-subunit) of DNA polymerase-alpha from calf thymus was separated from the other three subunits by immunoaffinity chromatography. The enzymatic properties of the alpha-subunit were characterized and compared with those of the four-subunit complex. Free alpha-subunit behaved in many respects like the four-subunit polymerase-primase. It was inhibited by aphidicolin and butylanilino-deoxyATP and catalyzed DNA synthesis on both gapped duplex DNA as well as primed single-stranded DNA with a preference of gapped DNA. The alpha-subunit is a quasi-processive enzyme with a processivity for about 9 nucleotides incorporated per single primer binding event. This is 2-fold lower than the processivity of the four-subunit complex. Despite this moderate processivity, free alpha-subunit was able to synthesize long stretches of DNA on singly primed natural psi X174am16 DNA. The accuracy of DNA synthesis of the free alpha-subunit was determined by using the psi X174am16 reversion assay to be 1 error per 50,000 nucleotides incorporated. An in vitro accuracy of 1 error in 54,000 nucleotides incorporated was measured in parallel for the four-subunit complex. Thus, the smaller subunits do not contribute to the overall accuracy of DNA polymerase-alpha. Consistent with this result is the observation that the polymerase to 3'----5'-exonuclease ratio was less than 1 to 2,500,000. Therefore, there is no evidence for the action of a cryptic proofreading activity with the alpha-subunit of DNA polymerase-alpha of mammalian origin.
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PMID:The DNA synthesizing subunit of polymerase-primase from calf thymus. 153 34

Modified deoxynucleosides 2'-deoxy-beta-L-uridine, beta-L-thymidine, alpha-L-thymidine, 2'-deoxy-beta-L-adenosine and 2'-deoxy-alpha-L-adenosine were synthesized and assembled as homooligomers, respectively: octa-beta-L-deoxyuridylates, octa beta-L and alpha-L-thymidylates and tetra beta-L and alpha-L-deoxyadenylates. These unnatural oligomers were then substituted with an acridine derivative. The binding studies of these modified oligonucleotides with D-ribo- and D-deoxyribopolynucleotides were carried out by absorption spectroscopy. While beta-L-d(Up)8m5Acr, beta-L-(Tp)8m5Acr, alpha-L-(Tp)8m5Acr did not interact with poly(rA) and poly(dA), beta-L-d(Ap)4m5Acr and alpha-L-d(Ap)4m5Acr did form double and triple helices with poly(rU) and poly(dT), respectively. Their stability towards nuclease digestion was studied through comparison with that of octa-beta-D-thymidylate and tetra beta-D-deoxyadenylate covalently linked to an acridine derivative. One endonuclease (nuclease P1 from Penicillium citrinum) and two exonucleases (a 3'-exonuclease from Crotalus durissus venom and a 5'-exonuclease extracted from calf thymus) were employed. beta-L- and alpha-L-oligomers demonstrate a high resistance toward nuclease digestion.
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PMID:Synthesis and physicochemical properties of oligonucleotides built with either alpha-L or beta-L nucleotides units and covalently linked to an acridine derivative. 165 74

A study was made of the activity of adenylate cyclase and cAMP-phosphodiesterase in rat thymus and liver various time intervals following nonlethal fractionated gamma-irradiation (2 Gy three times at a week interval). There was a positive correlation between the activity of cAMP metabolism enzymes and the radiation modification of ornithine decarboxylase (ODC) observed before. It is suggested that cAMP system is involved in ODC activity regulation in the exposed tissue.
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PMID:[The possible participation of the cAMP system in the activation of ornithine decarboxylase in rat tissues following nonlethal fractionated gamma-irradiation]. 165 39

New spin-labeled analogs of nucleoside triphosphates, 8-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)adenosine 5'-triphosphate ((8-AmTEMPO)ATP) and 5-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)uridine 5'-triphosphate ((5-AmTEMPO)UTP), with the probe 4-amino(2,2,6,6-tetramethylpiperidine-N-oxyl) (4-AmTEMPO) attached to C-8 of ATP and C-5 of UTP via a secondary amine bond, were synthesized in 50 and 40% yield, respectively. These analogs showed a single spot by thin layer chromatographic analysis. The absorption spectra of (8-Am-TEMPO)ATP and (5-AmTEMPO)UTP exhibit maxima at 310 and 265 nm, respectively; their X-band EPR spectra have a typical three-line pattern with lines at 3,221, 3,239, and 3,257 Gauss. The intensity ratios for mid to high field lines of the EPR derivative lines were found to be 1.03 +/- 0.02, 1.08 +/- 0.04, and 1.15 +/- 0.07 for 4-AmTEMPO, (8-AmTEMPO)ATP, and (5-AmTEMPO)UTP, respectively. The immobilization of 4-AmTEMPO bound to C-8 of ATP or bound to C-5 of UTP was observed to be 5 and 11%, respectively, as compared with free 4-AmTEMPO. The initial velocity (s-1) of [3H]UMP incorporation into RNA in the presence of [3H]UTP, CTP, GTP, and (8-AmTEMPO)ATP or ATP was measured. The percent incorporation of (8-AmTEMPO)ATP into RNA product by Escherichia coli RNA polymerase using various DNA templates is 68, 66, and 61% for pAR1435 (plasmid containing A1 promoter from T7 DNA), calf thymus DNA, and poly(dA-dT) respectively, as compared with ATP incorporation. The polymerase-catalyzed reaction of (8-AmTEMPO)ATP with (3'-OCH3)UTP yielded 5'-triphosphate delta-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)adenylyl (3'-5')3'-methoxy uridine in the presence of poly(dA-dT). The structure of this spin-labeled dinucleotide was identified by paper chromatographic analysis of the products of phosphodiesterase digestion. These analogs also can be used for the study by EPR spectroscopy of the dynamics of gene transcription catalyzed by RNA polymerases or of other nucleotide-utilizing enzymes.
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PMID:Spin-labeled nucleotide substrates for DNA-dependent RNA polymerase from Escherichia coli. 165 31

The bacteriophage PRD1 DNA polymerase gene (gene I) has been cloned into the expression vector pPLH101 under the control of the lambda pL promoter. Tailoring of an efficient ribosome binding site in front of the gene by polymerase chain reaction led to a high level heat-inducible expression of the corresponding gene product (P1) in Escherichia coli cells. Expression was confirmed in vivo by complementation of phage PRD1 DNA polymerase gene mutants and in vitro by formation of the genome terminal protein P8-dGMP replication initiation complex. Expressed PRD1 DNA polymerase was purified to apparent homogeneity in an active form. DNA polymerase, 3'-5'-exonuclease, and P8-dGMP replication initiation complex formation activities cosedimented in glycerol gradient with a protein of 65 kDa, the size expected for PRD1 DNA polymerase. The DNA polymerase was active on DNase I-activated calf thymus DNA, poly(dA).oligo(dT) and poly(dA-dT) primer/templates as well as on native phage PRD1 genome. The 3'-5'-exonuclease activity was specific for single-stranded DNA and released mononucleotides. No 5'-3'-exonuclease activity was detected. The inhibitor/activator spectrum of the PRD1 DNA polymerase was also studied. An in vitro replication system with purified components for bacteriophage PRD1 was established. Formation of the P8-dGMP replication initiation complex was a prerequisite for phage DNA replication, which proceeded from the initiation complex and yielded genome length replication products.
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PMID:Overexpression, purification, and characterization of Escherichia coli bacteriophage PRD1 DNA polymerase. In vitro synthesis of full-length PRD1 DNA with purified proteins. 165 59

Ionizing radiation and radiomimetic compounds, such as hydrogen peroxide and bleomycin, generate DNA strand breaks with fragmented deoxyribose 3' termini via the formation of oxygen-derived free radicals. These fragmented sugars require removal by enzymes with 3' phosphodiesterase activity before DNA synthesis can proceed. An enzyme that reactivates bleomycin-damaged DNA to a substrate for Klenow polymerase has been purified from calf thymus. The enzyme, which has a Mr of 38,000 on SDS-PAGE, also reactivates hydrogen peroxide-damaged DNA and has an associated apurinic/apyrimidinic (AP) endonuclease activity. The N-terminal amino acid sequence of the purified protein matches that reported previously for a calf thymus enzyme purified on the basis of AP endonuclease activity. Degenerate oligonucleotide primers based on this sequence were used in the polymerase chain reaction to generate from a bovine cDNA library a fragment specific for the 5' end of the coding sequence. Using this cDNA fragment as a probe, several clones containing 1.35 kb cDNA inserts were isolated and the complete nucleotide sequence of one of these determined. This revealed an 0.95 kb open reading frame which would encode a polypeptide of Mr 35,500 and with a N-terminal sequence matching that determined experimentally. The predicted amino acid sequence shows strong homology with the sequences of two bacterial enzymes that repair oxidative DNA damage, ExoA protein of S. pneumoniae and exonuclease III of E. coli.
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PMID:Isolation of cDNA clones encoding an enzyme from bovine cells that repairs oxidative DNA damage in vitro: homology with bacterial repair enzymes. 170 95

Dynamics of changes in activities of cAMP-dependent enzymes, phosphodiesterase and protein kinase, were studied in the thymus of intact and irradiated, prior to incubation, (0.05 Gy) chicken embryos and chicks. The changes observed were wave-like. In determining phosphodiesterase activity of irradiated chicken thymocytes during ontogenesis the values were obtained that correlated with the cAMP level and adenylate cyclase activity. It was also shown that the increase in the rate of cAMP-dependent phosphorylation under the effect of low-level radiation corresponded to the cyclic nucleotide content of a cell at different development stages.
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PMID:[The effect of a low dose of ionizing radiation on the activity of cAMP-dependent phosphodiesterase and protein kinase of chicken thymus in ontogenesis]. 216 99

The low molecular weight substance 10-carboxymethyl-9-acridanone (CMA) is capable to induce interferon (IFN) production. In order to determine the effect of CMA on cyclic AMP alterations in relation to IFN production, male ABD2F1 hybrid mice were orally treated with several concentrations of CMA (400, 600 and 800 mg/kg) for varying periods of time up to 24 hr. IFN titres were detected as early as 3 and 4 hr, respectively, in mouse plasma after CMA administration, and their production continued for at least 24 hr. Maximum IFN titres were assayed in the presence of 800 mg/kg (3,200 IU/ml) CMA. Measuring of the intracellular concentrations of cyclic AMP in thymus and spleen revealed that in early stage (0.5 to 2 hr) CMA exhibited a dose dependent increase. The drug acted as an inhibitor of low Km cAMP phosphodiesterase in cell homogenates; a significantly enhanced enzyme activity (1 to 4 hr) was found after exposure to CMA in vivo.
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PMID:Cyclic AMP metabolism and interferon induction in mice after treatment with 10-carboxymethyl-9-acridanone. 243 9

Adenyl-32P-Labeled 3'-deoxy-NAD+ was utilized as a substrate by pure DNA-dependent poly(ADP-ribose)polymerase (EC 2.4.2.30) from calf thymus in the automodification reaction with an apparent Km of 20 microM and a Vmax of 80 nmol/min/mg of protein. Analysis by lithium lauryl sulfate-polyacrylamide gel electrophoresis revealed a single 32P-labeled protein of 116-kDa which comigrated with automodified enzyme. Addition of increasing amounts of histone H1 up to a concentration of 15 micrograms/ml stimulated the synthesis of protein-bound polymers of 3'-deoxy-ADP-ribose. However, the average polymer size was equal to 2 in the presence and 4 in the absence of histone H1, respectively. The synthesis of protein-bound oligomers of 3'-deoxy-ADP-ribose was inhibited by the polymerase inhibitors benzamide, nicotinamide, thymidine, and NaCl. A pulse labeling of polymer synthesis with 40 microM [32P]3'-deoxy-NAD+ either in the presence or absence of 15 micrograms/ml of histone H1, followed by a chase with 1 mM [3H]NAD+, was used to determine the mechanism of poly(ADP-ribose) elongation. Following enzyme digestion of these polymers with phosphodiesterase, it was found that 52 and 24% of the total 32P radiolabel was associated with the 3'-deoxy-AMP termini of the polymers synthesized in the pulse reactions, in the presence or absence of histone H1, respectively. In contrast, less than 10% of the total radioactivity was associated with 3'-deoxy-AMP in the product of the chase reactions. These results are consistent with the conclusion that the initially attached residue of 3'-deoxy-ADP-ribose to either the polymerase or histone H1, is elongated by the "protein-distal" addition of ADP-ribose residues to the AMP terminus of the growing polymer chain.
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PMID:3'-Deoxy-NAD+ as a substrate for poly(ADP-ribose)polymerase and the reaction mechanism of poly(ADP-ribose) elongation. 314 24


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