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:3.1.25.1 (deoxyribonuclease)
1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of Rolly No. 11 strain herpes simplex virus infection of HeLa cells in culture on deoxynucleotide metabolism and the level of various enzymes concerned with the biosynthesis of DNA has been investigated. Of 18 enzyme activities studied, thymidine kinase, DNA polymerase and deoxyribonuclease were markedly augmented, a finding in agreement with previous reports. Deoxycytidine kinase, ribonucleotide reductase, thymidylate kinase and deoxycytidylate deaminase activities, in contrast with previous reports, did not increase; the activities of the other enzymes studied, also did not increase. Whereas most of the radioactivity derived from [14-C] thymidine in the acid-soluble fraction of the uninfected cells was present as deoxythymidine triphosphate, that present in the infected cells was primarily in the form of deoxythymidine monophosphate. Thus, in the infected cell deoxythymidylate kinase is a rate-limiting enzyme in the biosynthesis of deoxythymidine triphosphate. A marked increase in the pools of the four naturally occurring deoxynucleoside triphosphates (dTTP, dCTP, dATP, dGTP) was found. The rate of formation of the virus-induced enzymes was determined, as were the various nucleoside triphosphate pools and the other phosphorylated derivatives of thymidine; a maximum was reached for all these csmponents between 6 to 8 h post infection. Although an apparent greater synthesis of DNA occurred in the uninefected cells, when the specific activity of the radioactive deoxythymidine triphosphate was taken into account, there was actually a greater rate of DNA synthesis in the infected cells, with the peak at 8 h post infection.
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PMID:Deoxyribonucleotide metabolism in Herpes simplex virus infected HeLa cells. 16 49

The deoxyribonuclease induced in KB cells by herpes simplex virus (HSV) type 1 and type 2 has been purified. Both enzymes are able to completely degrade single- and double-stranded DNA yielding 5'-monophosphonucleotides as the sole products. A divalent cation, either Mg2+ or Mn2+, is an absolute requirement for catalysis and a reducing agent is necessary for enzyme stability. The maximum rate of reaction is achieved with 5 mM MgCl2 for both HSV-1 and HSV-2 DNase. The optimum concentration for Mn2+ is 0.1 to 0.2 mM and no exonuclease activity is observed when the concentration of Mn2+ is greater than 1 mM. The rate of reaction at the optimal Mg2+ concentration is 3- to 5-fold greater than that at the optimal Mn2+ concentration. In the presence of Mg2+, the enzymes are inhibited upon the addition of Mn2+, Ca2+, and Zn2+. The enzymatic reaction is also inhibited by spermine and spermidine, but not by putrescine. Crude and purified HSV-1 and HSV-2 DNase can degrade both HSV-1 and HSV-2 DNA, but native HSV-1 DNA is hydrolyzed at only 22% of the rate and HSV-2 DNA at only 32% of the rate of Escherichia coli DNA. Although HSV-1 and HSV-2 DNase were similar, minor differences were observed in most other properties such as pH optimum, inhibition by high ionic strength, activation energy, and sedimentation coefficient. However, the enzymes differ immunologically.
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PMID:The deoxyribonuclease induced after infection of KB cells by herpes simplex virus type 1 or type 2. I. Purification and characterization of the enzyme. 20 46

The DNA polymerase, thymidine kinase and deoxyribonuclease activities were studied in cells infected with wild type (wt), ultraviolet (UV)-irradiated and defective herpes simplex virus type 1. All three enzymatic activities were expressed in cells infected with wt virus. In cells infected with UV-irradiated virus, the thymidine kinase and deoxyribonuclease activities were inhibited and the DNA polymerase activity was markedly suppressed. In cells producing defective virus, there was thymidine kinase activity, but the viral deoxyribonuclease activity was considerably reduced. The DNA polymerase activity was fully expressed in cells producing defective virus at passage level 5, but at passage level 6, the activity of the viral DNA polymerase declined.
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PMID:Herpes simplex virus DNA polymerase, thymidine kinase and deoxyribonuclease activities in cells infected with wild type, ultraviolet-irradiated and defective virus. 22 1

Studies of nucleic acid homology suggest the BGLF5 open reading frame of Epstein-Barr virus (EBV) encodes an alkaline deoxyribonuclease (DNase) sharing some homology with that of herpes simplex virus. We report here the expression of the BGLF5 open reading frame in E. coli and the expression of high levels of a novel alkaline DNase activity in induced cells. This alkaline DNase has been purified to apparent homogeneity as a single protein species. This is the first report of the expression of a herpesvirus coded DNase in a prokaryotic system and of the purification of the EBV DNase to demonstrable purity. It has the biochemical characteristics of a typical herpesvirus alkaline exonuclease showing a high pH optimum, an absolute requirement for Mg2+ for activity and sensitivity to high salt concentrations and polyamines. The enzyme activity was neutralized by sera from patients with nasopharyngeal carcinoma and was reactive with these sera in Western blot analysis. Thus the prokaryotic expression system described here provides an economical and efficient source of the EBV DNase for biochemical and seroepidemiological analysis.
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PMID:The characterization of the EBV alkaline deoxyribonuclease cloned and expressed in E. coli. 255 12

In order to study the location of cells infected with human papilloma virus in paraffin-embedded tissues, the authors developed the following stain. Tissue sections were digested overnight with 0.01% deoxyribonuclease and then stained using the Feulgen stain with a light green counterstain. Cellular DNA was degraded, but viral DNA was not. Thus infected cells retained magneta nuclei, while uninfected cells stained a homogenous green. The stain was positive in 5/5 plantar warts, 7/8 verruca vulgaris, 2/2 laryngeal papilloma, and 18/20 condylomata accuminata. As a comparison, the indirect immunoperoxidase method on the same tissues stained 5/5 plantar warts, 6/8 verruca vulgaris, 0/2 laryngeal warts, and 2/20 condylomata accuminata. The presence of virus was confirmed by electron microscopic examination on one of the sections. Molluscum contageosum infected tissue also stained positively, but tissues infected with cytomegalovirus and herpes simplex virus did not. The only nonviral positive staining occurred with smears of sperm. The reasons for these results are discussed.
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PMID:A histochemical method for demonstrating papilloma virus infection in paraffin-embedded tissue. 620 75

In primary rabbit kidney cells infected with herpes simplex virus four different neutral deoxyribonuclease activities can be detected by means of the deoxyribonuclease assay in DNA-containing polyacrylamide gels following their separation by disc-electrophoresis. The method is suitable to follow independently the change in each activity of the different enzymes using only about 5 X 10(5) cells for each assay during the time-course of infection. Under these conditions one enzyme activity is constant, two disappear while the activity of a fourth one present only in infected cells, increases.
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PMID:Deoxyribonucleases in herpes simplex virus type 1 and 2 infected primary rabbit kidney cells. 625 96

Latent infection of the trigeminal ganglion with herpes simplex virus type 2 (HSV-2) was studied in guinea pigs by in situ DNA hybridization. Frozen ganglion sections from animals killed during the period of latent virus infection were studied under nondenaturing conditions. Some sections were treated with deoxyribonuclease (DNase) or ribonuclease (RNase) before incubation with HSV DNA probes. HSV probes consisted of viral DNA nick translated and labeled in vitro with tritiated nucleotides. Bacteriophage lambda DNA, similarly prepared, was used as a control probe. The lambda probe was negative in all situations, including HSV-2-infected monolayer cells in cell culture. HSV-2 probes produced heavy label and, therefore, evidence of hybridization with HSV-2-infected monolayer cells. When HSV-2 probes were incubated with latently infected ganglion sections, hybridization was detected in 71% of guinea pigs and 46% of ganglia. Label was seen only in neurons, and in positive ganglia 0.3 to 5% of neurons were labeled. The amount of label was markedly decreased by pretreatment of ganglion sections with RNase but not DNase, indicating that the DNA probes hybridized to HSV messenger RNA in the latently infected ganglia.
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PMID:Detection of herpes simplex virus mRNA in latently infected trigeminal ganglion neurons by in situ hybridization. 628 19

EcoRI fragments of herpes simplex virus I (HSV-1) strains H129 and +GC were cloned and the EcoRI and BglII restriction enzyme sites were mapped. Comparison of these enzyme sites with the sequence of HSV-1 strain 17syn+ demonstrated that all EcoRI sites were identical. For H129, the BglII sites were also found to match strain 17syn+ BglII sites. With one exception, the BglII sites in strain +GC also aligned with the strain 17syn+ sequence. The one exception was a missing BglII site from strain +GC located between bases 25,149 and 25,154 in the EcoRI D fragment within the viral deoxyribonuclease gene (UL12). The BglII site represents the first difference to be mapped within HSV-1 strains H129 and +GC which have unique pathobiological properties in animal models of acute and reactivated infections.
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PMID:Cloning and restriction endonuclease mapping of herpes simplex virus type-1 strains H129 and +GC. 748 98

We characterized the gene encoding the pseudorabies virus (PrV) homologue of the herpes simplex virus 1 UL12 open reading frame that encodes the alkaline nuclease. The deduced PrV UL12 product was 492 amino acid residues and exhibited three conserved regions among herpesviruses. Northern blot analysis indicated that three transcripts (3.2, 1.6 and 1 kb) were encoded in this region and the UL12 corresponds to the 1.6-kb transcript. Primer extension and UL12-specific cDNA cloning were performed to verify the precise location of the UL12 transcript. These data indicated that the transcription start site of UL12 was located at 47-62 nucleotides upstream of the UL12 translation start site and the polyadenylation cleavage site was located at 15 or 16 nucleotides downstream the typical polyadenylation signal. Furthermore, the 53-kDa UL12 product, which indeed has deoxyribonuclease activity, was evidenced by in vitro expression.
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PMID:Identification of a pseudorabies virus UL12 (deoxyribonuclease) gene. 892 54

The UL12 open reading frame of herpes simplex virus type 1 (HSV-1) encodes a deoxyribonuclease that is frequently referred to as alkaline nuclease (AN) because of its high pH optimum. Recently, an alternate open reading frame designated UL12.5 was identified within the UL12 gene. UL12.5 and UL12 have the same translational stop codon, but the former utilizes an internal methionine codon of the latter gene to initiate translation of a 60-kDa amino-terminal truncated form of AN. Since the role of the UL12.5 protein in the HSV-1 life cycle has not yet been determined, its properties were investigated in this study. Unlike AN, which can be readily solubilized from infected cell lysates, the UL12.5 protein was found to be a highly insoluble species, even when isolated by high-salt detergent lysis. Since many of the structural polypeptides which constitute the HSV-1 virion are similarly insoluble, a potential association of UL12.5 protein with virus particles was examined. By using Western blot analysis, the UL12.5 protein could be readily detected in preparations of intact virions, isolated capsid classes, and even capsids that had been extracted with 2 M guanidine-HCl. In contrast, AN was either missing or present at only low levels in each of these structures. Since the inherent insolubility of the UL12.5 protein prevented its potential deoxyribonuclease activity from being assayed in infected-cell lysates, partially purified fractions of soluble UL12.5 protein were generated by selectively solubilizing either insoluble infected-cell proteins or isolated capsid proteins with urea and renaturing them by stepwise dialysis. Initial analysis of these preparations revealed that they did contain an enzymatic activity that was not present in comparable fractions from cells infected with a UL12.5 null mutant of HSV-1. Additional biochemical characterization revealed that UL12.5 protein was similar to AN with respect to pH optimum, ionic strength, and divalent cation requirements and possessed both exonucleolytic and endonucleolytic functions. The finding that the UL12.5 protein represents a capsid-associated form of AN which exhibits nucleolytic activity suggests that it may play some role in the processing of genomic DNA during encapsidation.
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PMID:The product of the UL12.5 gene of herpes simplex virus type 1 is a capsid-associated nuclease. 906 Jun 64


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