Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

[E]-5-(2-bromovinyl)-2'-deoxyuridine (BVdU) inhibits the replication of the baculovirus Trichoplusia ni multiple nucleocapsid nuclear polyhedrosis virus in Spodoptera frugiperda cells. Virus-specific DNA synthesis and late protein synthesis are suppressed by the drug. BVdU is phosphorylated by deoxythymidine (deoxycytidine) kinase present in both uninfected and virus-infected cells, and in its 5'-triphosphate form it inhibits DNA polymerase activity in virus-infected cells. The effect of the BVdU is not completely reversible. Phosphonoacetic acid, phosphonoformic acid and Acyclovir have no effect on baculovirus replication. Acyclovir fails to compete with deoxycytidine and thymidine as substrates for pyrimidine deoxynucleoside kinase in virus-infected and uninfected cells.
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PMID:Baculovirus replication: inhibition of Trichoplusia ni multiple nuclear polyhedrosis virus by [E]-5-(2-bromovinyl)-2'-deoxyuridine. 634 53

The success of gemcitabine (2',2'-difluorodeoxycytidine; dFdC) resulted in new interest in its purine congeners. Based on the structure-activity relationship studies of catabolism and anabolism, 2',2'-difluorodeoxyguanosine (dFdG) emerged as a lead candidate among the difluoropurine analogs. The cytotoxicity, metabolism, and actions of dFdG on DNA synthesis were studied in the human leukemia lymphoblastoid line CCRF-CEM. The IC50 values of dFdG after a 72-hour continuous incubation were 0.01, 0.03, and 0.28 mumol/L for CCRF-CEM, K562, and HL-60 cells, respectively. A cell line deficient in dCyd kinase was equally sensitive to dFdG, suggesting that, in contrast to dFdC, dFdG may be activated by other deoxynucleoside kinase(s). Consistent with these data, coincubation with dGuo spared the dFdG-mediated toxicity; however, up to 500 mumol/L dCyd failed to reverse the toxicity of dFdG. These observations indicated that dGuo kinase, which phosphorylates arabinosylguanine, also appears to play a major role in activating dFdG. CCRF-CEM cells incubated with varying concentrations of [3H]dFdG accumulated dFdGTP in a dose-dependent manner; a 3-hour incubation with 1 mmol/L dFdG resulted in more than 600 mumol/L intracellular dFdGTP. This is in contrast to the gemcitabine triphosphate accumulation, which is saturated at 10 to 20 mumol/L of exogenous dFdC. dFdG metabolites affected ribonucleotide reductase, resulting in a lowering of the dCTP pool; this is in agreement with the effect of dFdC on dNTP pools in leukemia cell lines. The major effect of dFdG on macromolecular synthesis was inhibition of DNA synthesis. DNA primer extension over a defined template revealed that dFdGTP was a good substrate for DNA polymerase alpha and incorporated opposite C sites of the template. Unlike arabinosyl analogs, but similar to gemcitabine triphosphate, dFdGTP incorporation caused DNA polymerase to pause after one normal deoxynucleotide was incorporated beyond the analog. The unique activation requirements of dFdG, its novel mode of inhibition of DNA synthesis, and its potent toxicity to human leukemia cells make it a promising new antimetabolite.
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PMID:Difluorodeoxyguanosine: cytotoxicity, metabolism, and actions on DNA synthesis in human leukemia cells. 748 47

We have previously found that Drosophila melanogaster only has one deoxyribonucleoside kinase, Dm-dNK, however, capable to phosphorylate all four natural deoxyribonucleosides. Dm-dNK was originally isolated from an embryonic cell line. We wanted to study the expression of Dm-dNK during development from embryonic cells to adult flies and found declining Dm-dNK activity during development and no activity in adult flies. Surprisingly, the extract from adult flies exhibited a strong inhibitory effect on deoxyribonucloside kinase activity. The dNK-inhibitor was precipitable with ammonium sulfate, and was purified to a high degree by gel-filtration as indicated by LC-MS/MS analysis. Since the inhibitor eluted from G-200 gel-filtration with a size of 10-13 kDa, we named it P12. We tested the purified fraction for specificity towards various enzymes and found that both mammalian and bacterial dNKs were inhibited, whereas there was no effect on hexokinase and pyruvate kinases and acidic phosphatase. However, when tested against cyclin B-dependent kinase, we found a strong inhibitory effect. Both with human Cdk1/CycB and S. pombe Cdc2/B-type cyclin the purified fraction from Superdex 200 that inhibited Dm-dNK, also inhibited the two protein kinases to the same degree. Furthermore, testing P12 in a DNA polymerase based assay we found that the 3'-5'-exonuclease part of the DNA polymerase (Klenow polymerase) was activated.
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PMID:Isolation of a novel protein, P12-from adult Drosophila melanogaster that inhibits deoxyribonucleoside and protein kinase activities and activates 3'-5'- exonuclease activity. 2790 21