Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.22.1 (DNase II)
 429 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The concentration of free phosphate groups is measured in rat liver chromatin after DNase II digestion using polylysine titration. The unsheared chromatin completely precipitates at lysine/DNA phosphate ratios of 0.5 to 0.6. Digestion of the chromatin reduces the lysine/DNA phosphate ratio of complete precipitation by about 0.2 units suggesting the removal of free phosphate groups. The two chromatin fractions: MgC12 insoluble (template-inactive) and Mg12 soluble (template-active) chromatins precipitate at about the same lysine/DNA phosphate ratio. Some 15% of the MgC12 soluble chromatin remains in solution at any polylysine concentration. The removal of histone H 1 FROM THE MgC12 insoluble chromatin increases the lysine/DNA phosphate ratio by about 0.2 units suggesting that 20% of the DNA phosphate groups in nucleosomes are masked by histone H 1.
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PMID:Polylysine titration of rat liver chromatin fractions after DNase II digestion. 86 91

The activities of acid phosphatase, beta-glucuronidase, beta-galactosidase, acid ribonuclease, and acid deoxyribonuclease were studied in the blood serum of rats after total, either single or franctionated, exposure. After the single, total exposure to 800 R of X-rays, remarkable increases in the activities of acid phosphatase and acid deoxyribonuclease were observed in the blood serum immediately after the irradiation. At later stages were observed statistically significant decreases of beta-glucuronidase and beta-galactosidase in the rat blood serum after the total, single exposure. The serum acid ribonuclease activity remained essentially unaltered over the whole time interval of interest. In the blood serum of the rats exposed to total, fractionated irradiation, statistically significant decreases in the acid phosphatase and beta-glucuronidase activities were observed 1 and 8 days after completing the irradiation. In the case of beta-galactosidase, this decrease lasted even up to the 15th day after the end of irradiation. The activities of serum acid deoxyribonuclease and acid ribonuclease exhibited no statistically significant changes.
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PMID:Changes of the activity of certain lysosomal enzymes in the blood serum of whole-body irradiated rats. 89 16

Rat liver chromatin is organized into regions of DNA which differ in degree of susceptibility to attack by the endonucleases DNase I and DNase II. The most nuclease-sensitive portion of chromatin DNA is enriched in transcribed sequences. This fraction may be separated from the bulk of chromatin by virtue of its solubility in solutions containing 2 mM MgCl2. Both transcribed and nontranscribed regions of chromatin are organized into repeating units of DNA and histone, which appear as 100 A beads in the electron microscope. The length of DNA in the repeat unit is the same for these two classes of chromatin (198 +/- 6 base pairs in rat liver); however, the subunits of active, Mg++-soluble chromatin differ from the nucleosomes of inactive regions of chromatin in several respects. Active subunits are enriched in nascent RNA and nonhistone protein and exhibit higher sedimentation values than the corresponding subunits of inactive chromatin.
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PMID:Structure of transcriptionally-active chromatin subunits. 90 2

Rat lung tissue is labelled in vitro with [3H]leucine and nuclei are prepared. They are digested with deoxyribonuclease II and four subfractions are isolated after differential centrifugation: MgCl2-soluble (active) and MgCl2-insoluble (inactive) chromatin, nuclear matrix sediment and matrix extract using 2M NaCl. The matrix extract fraction is found to be enriched in radioactive DNA after a short pulse of [3H]thymidine. The labelling kinetics of histones are similar in each subfraction, suggesting that histones are not preferentially incorporated onto nascent DNA. Nonhistones isolated from the subfractions, except for the matrix sediment fraction, also follow closely similar incorporation kinetics with [3H]-leucine. The matrix sedimnent fraction is three times more actively labelled than nonhistones of the other fractions and displaying a unique protein composition, suggesting distinct functional properties.
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PMID:Labelling of histones and nonhistones in lung nuclear matrix and chromatin fractions. 92 85

Cultures of HeLa S3 cells were treated with prednisolone metasulfobenzoate (Na), a derivative of prednisolone which is readily soluble in water. The steroid induced an increase in DNase II, a lysosomal enzyme which was not used previously in enzyme induction by steroids. Alkaline phosphatase, a known inducible enzyme by other steroids and acid phosphatase, a known uninducible enzyme by other steroids, were included for comparative reasons.
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PMID:Effects of prednisolone metasulfabenzoate on the induction of DNase II in comparison to alkaline phosphatase and acid phosphatase activities in cultures of HeLa S3 cells. 94 Nov 92

Recent interest in the use of adriamycin-DNA complex as an approach to improve the therapeutic effectiveness and to reduce toxicity of adriamycin for cancer chemotherapy requires an in-depth understanding of the physicochemical and biochemical properties of such complexes. The interactions of adriamycin with single-strand polydeoxyribonucleotides, double-strand DNA, and double-strand ribodeoxyribopolynucleotide hybrids were therfore investigated. Association constants (Kapp) of adriamycin and polynucleotides were obtained. These data showed that the inherent variable in such complex lies in the composition of the polynucleotides. Alternate deoxyguanylate (dG)-deoxycytidylate (dC) sequence binds 7-fold better than alternate deoxyadenylate (dA)-deoxythymidylate (dT) sequence. Comparative studies of the hydrolysis of DNA duplexes by deoxyribonucleases I and II with and without adriamycin were also carried out. The rate of hydrolysis decreased in the order poly(dA-dT) greater than calf thymus DNA greater than poly(dG-dC) greater than poly(dA)-poly(dT) greater than poly(dG)-poly(dC) for DNase I and poly(dA)-dT) greater than calf thymus DNA greater than poly(dG-dC) greater than poly(dA)-poly(dT) greater than poly(dG)-poly(dC) for DNase II. Intercalation of adriamycin to deoxyribopolynucleotide duplex resulted in inhibition of DNase II two to three times more than tat of DNase I. On the other hand, intercalation of adriamycin to homodeoxypolynucleotide duplex poly(dA)-poly(dT) and poly(dG)-poly(dC) enhanced the DNase I hydrolysis. If DNase I activity could be related to serum DNase and DNase II related to tumor lyososomal DNase as in the endocytosis mechanism proposed by Trouet et al. (Cancer Chemotherapy Rept., 59: 260, 1975), the best adriamycin carrier suggested by this investigation could be poly(dA)-poly(dT) and poly(dG-dC). It is also suggested in this study that adriamycin-RNA-DNA hybrid could be of interest as an antiviral agent by a similar release mechanism via RNase H, an enzyme associated with viral reverse transcriptase.
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PMID:Effect of deoxyribonuclease on adriamycin-polynucleotide complexes. 97 96

Digestion of mouse liver nuclei with DNase II leads to a novel cleavage pattern with a 100-nucleotide pair periodicity. From chromatin, this pattern or the standard 200-nucleotide pair repeat can be produced depending on the ionic conditions. The results are interpreted by assuming different conformational states of the nuclear material, including condensed and extended forms.
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PMID:Nuclease cleavage of chromatin at 100-nucleotide pair intervals. 100 86

The effects of spermine, putrescine, and spermindiol on different nucleases were investigated. A highly active spermine analog, spermindiol, was synthesized, which markedly enhanced DNA hydrolysis by staphylococcal nuclease and spleen DNase II [EC 3.1.4.6] and RNA degradation by staphylococcal nuclease and pancreatic RNase A [EC 3.1.4.22]. Spermindiol also increased the melting temperature of calf thymus DNA.
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PMID:A potent polyamine analog, spermindiol. 101 Aug 53

The time course of the fragmentation of calf thymus chromatin by DNase II (deoxyribonucleate 3'-oligonucleotidohydrolase, EC 3.1.4.6) has been examined by sedimentation of chromatin digests through linear (5-20%) sucrose gradients. The action of nuclease is decidedly nonrandom, ultimately producing roughly equal amounts of acid-soluble oligonucleotides and 11S nucleoprotein particles. The 11S particles contain double-stranded DNA that is approximately 400 A or 120 base-pairs long, as measured by electron microscopic examination of deproteinized samples, and is maintained in a compact conformation within the intact particles. In addition, 15S nucleoprotein particles containing predominantly 800-A lengths of DNA have been isolated from less extensively digested chromatin. Evidence is presented which indicates that the 11S particles are fundamental structural units that are arranged in tandem along certain regions of chromatin fibrils. Preliminary experiments with different nucleases and with chromatin from different mammalian species indicate that these results are a natural consequence of the arrangement of DNA and proteins in mammalian chromatin and are not peculiar to the system described in detail.
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PMID:Nucleas action on chromatin: evidence for discrete, repeated nucleoprotein units along chromatin fibrils. 105 45

Rat-liver chromatin has bee fractionated into transcriptionally active and inactive regions [Gottesfeld et al. (1974) Proc. Nat. Acad. Sci. USA 71, 2193-2197] and the distribution of nuclease-resistant complexes in these fractions has been investigated. About half of the DNA of both fractions is resistant to attack by tne endonuclease DNase II. The nuclease-resistant structures of inactive chromatin are DNA-histone complexes (v-bodies) which sediment at 11-13 S. Template-active chromatin yields two peaks of nuclease-resistant nucleoprotein. These complexes sediment at 14 and 19 S, and contain DNA, RNA, histone, and nonhistone chromosomal proteins. Polyacrylamide gel electrophoresis reveals a complex pattern of chromatin proteins, suggesting that the complexes are heterogeneous in composition.
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PMID:Structure of transcriptionally active chromatin. 106 Jan 19


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