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 effect of actinomycin on DNA structure has been studied by nuclease digestion of a DNA fragment containing the sequence AAGCT(TA)6AGCTT. The drug enhances DNase I cleavage at ApT and TpA bonds closest to the drug binding site (GC). Large changes in the relative susceptibility of bonds to cleavage by micrococcal nuclease and DNase II are also observed. The changes suggest that actinomycin alters DNA structure around its binding site, facilitating the formation of an alternating DNA structure. When a similar TA sequence was inserted further from the actinomycin binding site no changes in nuclease susceptibility were observed.
 ...
PMID:Effect of actinomycin on a (TA)6 plasmid insert. 215 17

The binding of mithramycin to DNA has been investigated using a variety of chemical and enzymic footprinting probes. Mithramycin failed to affect DNA modification by several chemical agents which react in the DNA major groove, suggesting that the drug binds via the minor groove. The pattern of reaction with diethylpyrocarbonate was modified by the antibiotic at the binding site and in surrounding regions, consistent with drug-induced structural changes. Hydroxyl radical and DNase I footprinting confirms that the drug binds best to GpG, especially when this is located within a GC-rich environment. Cleavage by DNase II and micrococcal nuclease is inhibited around drug binding sites and suggests a local stabilization of the DNA helix.
 ...
PMID:Footprinting studies of sequence recognition by mithramycin. 215 18

To clarify the relationship between changes in serum pancreatic enzymes and pathological changes in pancreatic parenchyma, this study was performed by using rat models with acute pancreatitis. The models were rats with edematous and necrotizing pancreatitis. Amylase, lipase, ribonuclease (RNase), and deoxyribonuclease (DNase I, II) in the serum were determined for 48 h after the development of pancreatitis. Amylase and lipase levels rose directly in both pancreatitis groups. These enzymes in the necrotizing pancreatitis group were higher than those in the edematous pancreatitis group, but there was no significant difference. RNase levels also rose markedly, but there was no obvious difference between either of the pancreatitis groups. On the other hand, DNase levels were high in the necrotizing pancreatitis group but low in the edematous pancreatitis group, with significant differences between the two groups, especially in the DNase II levels over a 36-h period (p less than 0.05-0.01). Therefore, these results suggest that serum DNase levels reveal the necrotizing changes in pancreatic parenchyma.
 ...
PMID:Relationship between pancreatic enzymes and pathological changes in the pancreas in acute pancreatitis. The significance of determination of serum deoxyribonuclease. 247 54

Oligodeoxynucleotides with different arrangements of methylphosphonate linkages were examined for nuclease sensitivity in vitro, stability in tissue culture, and ability to form RNase H-sensitive substrates with complementary RNA. After nuclease treatment, resistance was demonstrated by the ability to alter the electrophoretic mobility of a labeled complementary phosphodiester oligodeoxynucleotide. Both 5'- and 3'-exonuclease activities were retarded by methylphosphonate linkages. Methylphosphonate-containing oligodeoxynucleotides with 1-5 adjacent phosphodiester linkages were tested as substrates for the endonucleases DNase I and DNase II. The results indicated that a span of three or fewer contiguous internal phosphodiester linkages led to the greatest resistance to endonuclease. However, in serum-supplemented culture medium half-lives of these oligodeoxynucleotides were independent of the number of contiguous phosphodiester linkages. Methylphosphonate-containing oligodeoxynucleotides were hybridized to RNA runoff transcripts and tested as substrates for RNase H. The results indicated that a span of three internal phosphodiester linkages in the oligodeoxynucleotide was necessary and sufficient to direct cleavage of the RNA in the duplex.
 ...
PMID:Number and distribution of methylphosphonate linkages in oligodeoxynucleotides affect exo- and endonuclease sensitivity and ability to form RNase H substrates. 247 96

Phosphodiesterase I [EC 3.1.4.1] was purified from normal human urine in a highly purified state free from phosphodiesterase II, RNase, DNase I, DNase II, and phosphatase by column chromatographies of DEAE-Toyopearl, butyl-Toyopearl, Affi-Gel blue, and Sephadex G-150. The molecular weight of the enzyme was 1.9 x 10(5) and the pH optimum around 9.0 with p-nitrophenyl deoxythymidine 5'-phosphate as the substrate. The enzyme hydrolyzed the 3'-5' linkage of various dinucleoside monophosphates at approximately the same rate and the phosphodiester bonds of cyclic 3',5'-mononucleotides to produce mononucleoside 5'-phosphate. The enzyme also hydrolyzed ADP to 5'-AMP and Pi, ATP to 5'-AMP and PPi, and NAD+ to 5'-AMP and NMN. The enzyme activity was abolished by removal of metal ions with EDTA, and the metal-free enzyme was reactivated on the addition of Zn2+. The enzyme activity was also abolished by some reducing agents and the inhibition was reversed by Zn2+. The metal-free enzyme was less stable than the native enzyme, and Zn2+ and Co2+ restored the stability of the metal-free enzyme to the level of the native enzyme. The enzyme degraded oligonucleotides and high molecular nucleotides stepwise from the 3'-termini to give 5'-mononucleotides. The enzyme hydrolyzed single-stranded DNA more preferentially than double-stranded DNA. The enzyme also nicked superhelical covalently closed circular phi X174 DNA to yield first open circular DNA and then linear DNA.
 ...
PMID:Phosphodiesterase I in human urine: purification and characterization of the enzyme. 282 85

The Rp- and Sp-diastereomers of the phosphorothioate-containing oligonucleotide d[ApAp(S)ApA] have been synthesized. They and the tetramer d[ApApApA] were tested as substrates for staphylococcal nuclease, DNase II and spleen phosphodiesterase. For digestions with DNase I these oligonucleotides were converted to the 5'-phosphorylated derivates. The reactions with the nucleases were analysed by HPLC. The phosphorothioate groups of both diastereomers were resistant to the action of staphylococcal nuclease, DNase I and DNase II. While the phosphorothioate group of the Rp-diastereomer was resistant to the action of spleen phosphodiesterase, the Sp-diastereomer was hydrolysed at an estimated rate 1/100 the rate of cleavage of the unmodified tetramer. The presence of the phosphorothioate group in the center of the molecule affected the rate of hydrolysis of neighbouring phosphate groups for some enzymes. In particular, very slow release of 3'-dAMP from the Rp-diastereomer occurred on incubation with staphylococcal nuclease but the Sp-diastereomer was completely resistant. DNase II produced 3'-dAMP quite rapidly from both diastereomers of d[ApAp(S)ApA] and DNase I released 5'-dAMP from both diastereomers of d[pApAp(S)ApA] only slowly.
 ...
PMID:Inhibition of deoxyribonucleases by phosphorothioate groups in oligodeoxyribonucleotides. 285 May 41

The chromatin structure of two tandemly linked acid phosphatase genes (PHO5 and PHO3) from Saccharomyces cerevisiae was analyzed under conditions at which the strongly regulated PHO5 gene is repressed. Digestion experiments with DNase I, DNase II, micrococcal nuclease and restriction nucleases reveal the presence of five hypersensitive sites at the PHO5/PHO3 locus, two of them upstream of PHO5 at distances of 920 and 370 bp, one in between the two genes and two downstream of PHO3. Specifically positioned nucleosomes are located next to these hypersensitive sites as shown by indirect end-labeling experiments. The positions deduced from these experiments could be verified by monitoring the accessibility of various restriction sites to the respective nucleases. Sites within putative linker regions were about 50-60% susceptible, whereas sites located within nucleosome cores were resistant. Hybridizing micrococcal nuclease digests to a probe from in between the two upstream hypersensitive sites leads to an interruption of an otherwise regular nucleosomal DNA pattern. This shows directly that these hypersensitive sites represent gaps within ordered nucleosomal arrays.
 ...
PMID:Nuclease hypersensitive regions with adjacent positioned nucleosomes mark the gene boundaries of the PHO5/PHO3 locus in yeast. 302 55

Chromatin structure of globin and ovalbumin genes in chicken erythrocyte nuclei has been investigated by means of the "nuclease criterion" (described earlier). In intact nuclei (i.e. in the presence of 3 mM MgCl2) DNase I cleaves chromatin of both genes generating fragments multiple of a double-nucleosome repeat (2N-periodicity). However, in the case of the globin gene, apart from the 2N-periodicity, fragments were observed that are multiple of 100 b.p. and are characteristic for partially unfolded chromatin. This distinction in nuclease cleavage patterns correlates with a higher sensitivity of the globin gene as compared with the inactive ovalbumin gene. At 0.5-0.7 mM MgCl2 the transition from dinucleosomal fragmentation with DNase I and DNase II to fragmentation via a 100 b.p. interval occurs and the difference in digestibility of both genes is dramatically increased. If chromatin has been decondensed by incubation of nuclei in 10 mM Tris-buffer DNase Il generates an usual nucleosomal repeat, and in this ionic conditions one may not observe any difference in nuclease sensitivity of the analyzed genes. The data allow to suggest that the high nuclease sensitivity of potentially active genes can be conditioned by more relaxed arrangement of nucleosomes in higher order chromatin structure.
 ...
PMID:[Structural state of active and inactive genes during chromatin decondensation]. 318 36

DNase I footprinting studies employing several DNA fragments have confirmed that nogalamycin binds preferentially to regions of DNA containing alternating purines and pyrimidines. Arugomycin and viriplanin A, related compounds which contain additional sugar residues at both ends of the molecule, produce similar patterns of nuclease protection though at higher drug concentrations. The pattern induced by decilorubicin, which has charged groups at both ends of the aglycone, differs in many details and this analogue appears to display a modified DNA sequence selectivity. The results have been confirmed by similar studies using DNase II. All four compounds increase the susceptibility of certain adenine residues to modification by diethylpyrocarbonate. The results suggest an intercalative mode of binding for these nogalamycin analogues, and reveals an increased complexity in compounds which can bind to DNA by this mechanism.
 ...
PMID:Footprinting studies on the interactions of nogalamycin, arugomycin, decilorubicin and viriplanin with DNA. 320 63

In the presence of 3 mM MgCl2 DNase I cleavage of bulk, globin and ovalbumin gene chromatin in chicken erythrocyte nuclei generates fragments which are multiples of a double-nucleosome repeat. However, in addition to the dinucleosomal periodicity beta-globin gene chromatin was fragmented into multiples of a 100 b.p. interval which is characteristic for partially unfolded chromatin. This distinction correlates with higher sensitivity of beta-globin domain to DNase I and DNase II as compared to the inactive ovalbumin gene. At 0.7 mM MgCl2 where these DNases fragment bulk chromatin into series of fragments with a 100 b.p. interval, the difference in digestibility of the investigated genes is dramatically decreased. When chromatin has been decondensed by incubation of nuclei in 10 mM Tris-buffer, DNase II generates a typical nucleosomal repeat, and the differential nuclease sensitivity of the analyzed genes is not observed. The data suggest that higher nuclease sensitivity of potentially active genes is due to irregularities in higher order chromatin structure.
 ...
PMID:A structure of potentially active and inactive genes of chicken erythrocyte chromatin upon decondensation. 341 26


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>