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

Nuclei and chromatin from trout testis cells were digested with three different nucleases (DNase I, DNase II, and micrococcal nuclease), and the acid-soluble proteins that were solubilized and those remaining bound to the nuclease-resistant DNA were compared electrophoretically. With the conditions described by H. Weintraub and M Groudine [(1976) science, 193, 848-856], which we previously found to be selective in digesting actively transcribed regions in trout testis chromatin, a single chromosomal protein, H6, was solubilized. The nucleosomal histones and H1 remained insoluble, bound to the resistant DNA. In contrast, digestion with micrococcal nuclease led to a preferential solubilization of a second protein, HMG-T, together with the release of some nucleosomal histones and H1 into the soluble fraction. DNase II also discriminated between "active" and "inactive" chromatins; when a DNase II-solubilized "active" chromatin fraction was prepared, it too was enriched in H6 and HMG-T. Thus, both H6 and HMG-T, the two major low-salt extractable chromosomal nonhistone the two major low-salt extractable chromosomal nonhistone proteins from trout testis, are associated with chromatin regions selectively sensitive to nucleases. The preferential solubilization of HMG-T by micrococcal nuclease action suggests that it might be located at the internucleosomal "spacer" region.
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PMID:Selective association of the trout-specific H6 protein with chromatin regions susceptible to DNase I and DNase II: possible location of HMG-T in the spacer region between core nucleosomes. 26 31

When thymocytes are incubated with glucocorticoids at 37 degrees, 60--70% of the receptor bound steroid is associated with the nucleus. Under conditions where the rate of steroid-receptor formation is not limiting the transfer of steroid-receptors from the cytoplasm to the nucleus occurs rapidly with a T 1/2 of 30 seconds. These observations have led us to investigate whether or not all glucocorticoid receptor complexes are associated with the nucleus in the same manner. To this end, nuclear glucocorticoid-receptor complexes have been extracted by differential salt extraction and DNase I and DNase II digeston. Of the nuclear dexamethasone receptor complex initially bound, 70--75% is resistant to 0.2 M KCl extraction (designated N2) and 25--30% is resistant to 0.4 extraction (designated N4). N2 can be further extracted with 0.4 M KCl whereas N4 is resistant to reextraction with either 0.2 M KCl, suggesting that N2-N4 (N2-4) and N4 represent distinct physical forms of nuclear dexamethasone receptor. In intact cells, N2 and N4 differ under the following physiological condition. (1) N4 binding occurs prior to N2-4; (2) a cold chase of unlabeled dexamethasone decreases N2-4 by 70% but N4 binding by only 10%; (3) N4 binding decreases more rapidly than N2-4 following a decrease in hormone concentration by dilution; (4) a cold chase of either cortexolone or progesterone preferentially decreases N2-4 and has little effect on N4. In addition, the nuclear N2-4 and N4 distribution differ for cortisol, dexamethasone and triamcinolone acetonide, three steroids having different in vitro biological potencies. DNase I treatment of nuclei solubilizes approximately 60% of nuclear DNA yet releases only 20--30% of nuclear receptor, whereas DNase II solubilizes only 10% of nuclear DNA and releases 76--80% of nuclear receptor. As seen with salt extraction, the resistance of nuclear glucocorticoid-receptor complexes to a DNase I and II is dependent on the steroid molecule which is associated with the receptor. Of the steroids we have tested, nuclear triamcinolone acetonide and dexamethasone receptor complexes are most resistant to nuclease attack. Nuclear cortisol receptor complexes are readily solubilized by either DNase I or II under conditions where little dissociation of steroid from receptor occurs. These data represent evidence for physiologically distinct forms of nuclear glucocorticoid receptor interaction. In addition, they demonstrate the importance of the steroid portion of the steroid receptor in directing the nature and/or location of steroid receptors within or on the nucleus.
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PMID:Heterogeneity of nuclear glucocorticoid receptor interactions. 47 92

Chicken reticulocyte (polychromatic primitive erythrocyte) and erythrocyte chromatin was fractionated by ultrasound shearing and salt precipitation into three fractions differing in their activities to support the in vitro RNA synthesis. The transcriptionally active fraction of chicken reticulocyte chromatin which represented only about 0.5% of the total nuclear DNA contained essentially all the chromatin-associated endogenous RNA. Approximately 2% of this endogenous reticulocyte RNA hybridized to globin cDNA probe and could be translated in vitro into polypeptides which coelectrophoresed with the in vitro translation product of isolated chicken globin mRNA or chicken globin marker. Each of the three fractions had a characteristic distribution of chromosomal proteins and endogenous RNA. Polyacrylamide gel electrophoresis of the chromosomal proteins showed differences in their distribution among individual fractions of the same cell type and among corresponding fractions of reticulocyte or erythrocyte chromatin. Antisera produced against dehistonized reticulocyte chromatin were specific for reticulocyte but not erythrocyte chromatin. When reacted with each of the differentially templating chromatin fractions, it was found that reticulocyte-specific antibodies were highly reactive with the template-active fraction of reticulocytes, but essentially nonreactive with any other reticulocyte fraction. This same antiserum was not significantly reactive toward any erythrocyte fraction. The antigenicity of the template-active fraction of reticulocytes was abolished after pronase or DNase II digestion, but only partially diminished after DNase I digestion.
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PMID:Immunological properties of fractionated avian erythroid nuclei. 67 Feb 33

DNase II, bound to the lysosomal membrane of porcine spleen, can be extracted from the membrane with 0.4 M NaCl. Reassociation of DNase II with the salt-extracted lysosomal membrane is readily accomplished in 0.01 M sodium acetate (pH 4.5). The reassociable amount of DNase II is approximately equal to the extractable amount. The capacity of the lysosomal membrane to bind DNase II is unaffected by the subtilisin treatment of the membrane. Phosphatidyl serine can bind DNase II as well, but with a much higher capacity. The erythrocyte plasma membrane on the other hand binds only about 20% of DNase II bound to the lysosomal membrane. The DNase II activity can be eluted from a column of the lysosomal membrane entrapped in 2% agarose and the elution pattern is very similar to that of CM-cellulose chromatography of DNase II, suggesting that electrostatic interactions may play an important role in the binding. The pH-reassociation profile is bell-shaped and is similar to the pH-activity profile of DNase II, having a maximum near pH 5. Under the nondenaturing condition, the dissociated alpha and beta subunits of DNase II cannot be reassociated to regain the enzymatic activity with or without the lysosomal membrane.
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PMID:Reassociation of deoxyribonuclease II with the lysosomal membrane isolated from porcine spleen. 236 24

It was revealed by means of nucleoprotein-celite-chromatography that DNA-protein interactions in the chromatin fraction sensitive to micrococcal nuclease and DNase II are weaker that in the resistant one. The micrococcal nuclease destroys the DNA-matrix bond resistant to salt-urea, while DNase II does not change the DNA-matrix integrity. Tightness of the DNA-protein interactions is weakened by the increasing chromatin fragmentation, but does not depend on the size of chromatin particles.
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PMID:[Stability of DNA-protein interactions in chromatin fractions with different sensitivity to nucleases]. 323 Dec 30

Rabbits were injected intracerebrally with aluminum salt leading to experimental neurofibrillary change formation as a model of Alzheimer neurofibrillary change. Eleven days after the injection, the brain tissues were excised from the cortex, hippocampus, and cervical region of spinal cord. Five lysosomal enzymes (cathepsin D, beta-glucuronidase, acid phosphatase, acid DNase, alkaline DNase) were assayed and compared with the control. Cathepsin D, acid DNase and beta-glucuronidase activities increased significantly in all 3 areas of aluminum-injected brain. On the other hand, acid phosphatase and alkaline DNase activities remained at the same level. The results showed the lysosomal enzymes did not change in parallel after aluminum administration, suggesting a role of the increased enzymes in the brain with neurofibrillary changes.
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PMID:Activities of lysosomal enzymes in rabbit brain with experimental neurofibrillary changes. 339 97

Nuclear protein factor type 1 (NPF-1) that simulates IMR-32 primase-associated DNA polymerase alpha 1 and alpha 2 activities has been purified from a high-salt extract of liver chromatin from 6-month-old rats. The final purified factor lacks DNA polymerase alpha, RNA polymerase, and DNA-unwinding or topoisomerase type I activities. The stimulatory activity is destroyed by trypsin (60 min at 37 degrees C), DNase II (60 min at 37 degrees C), and heat treatment (2 min at 68 degrees C). The 125I-labeled NPF-1 does not bind to activated calf thymus DNA or poly(dC). However, it forms a ternary complex with DNA in the presence of DNA polymerase alpha-primase complex (alpha 1 and alpha 2). The ternary complex sediments on sucrose density gradient as a heavier band (11S). The NPF-1 also stimulates (2.5-fold) primase-catalyzed incorporation of GMP and dGMP from the corresponding triphosphates on poly(dC) template even in the presence of a high concentration of alpha-amanitin (400 micrograms/ml). The labeled duplex containing the poly(dC) template, [32P]-GTP, and [3H]dGTP loses 80% of the 32P label and 70% of the 3H label after treatment with 0.3 M KOH and DNase I, respectively. The products were isolated from reaction mixtures incubated with and without NPF-1 and subjected to alkaline sucrose-density-gradient sedimentation analysis. The results suggest that the rate of synthesis of DNA short chains is increased in the presence of NPF-1 without a concomitant increase in the chain length of the newly synthesized products.
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PMID:Stimulation of human neuroblastoma DNA polymerase alpha and primase activities by a protein factor isolated from rat liver chromatin. 354 Sep 37

1. The isolated bovine adrenal medulla was prepared from whole glands by careful removal of the cortex. The tissue was perfused with physiological salt solution and stimulated with a variety of secretogogues.2. Catecholamines were secreted from the tissue upon stimulation with carbamylcholine, nicotine sulphate, acetylcholine bromide, histamine dihydrochloride, (+)-amphetamine sulphate and potassium chloride.3. Carbachol-induced secretion of catecholamines was reduced in the presence of either hexamethonium bromide or tetracaine hydrochloride, during perfusion with calcium-free perfusion fluid, or during perfusion at low temperature.4. Stimulation of the medulla with carbachol also led to secretion of chromaffin granule protein and acid deoxyribonuclease. The relationships between catecholamines secreted and the amounts of these proteins secreted were similar to the corresponding values for the perfused whole bovine adrenal gland. Perfusate lactate dehydrogenase activity and perfusate haemoglobin content were unchanged after carbachol stimulation.5. It is concluded that there are no differences in the mechanisms for catecholamine secretion from the cortex-free perfused medulla and the perfused whole gland.
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PMID:Secretion from the cortex-free bovine adrenal medulla. 534 26

Transition of bovine ribonuclease A from its monomeric to a dimeric form changes the pattern of enzymic activity response to ionic strength [Sorrentino, S., Carsana, A., Furia, A., Doskocil, J., and Libonati, M. (1980) Biochim. Biophys. Acta. 609, 40-52]. To see whether this phenomenon could be common to other enzyme-substrate systems, the action of various dimeric and monomeric enzymes (ox pancreas deoxyribonuclease, hog spleen acid deoxyribonuclease, bovine seminal ribonuclease, egg-white lysozyme, and papain) on polyelectrolytic substrates has been studied under different conditions of ionic strength. Dimerization of ox pancreas deoxyribonuclease, lysozyme and papain was obtained by cross-linkage with dimethyl suberimidate. The main results of the investigation, similar to those obtained with ribonuclease A, are the following. 1. Enzyme monomers and dimers show markedly different patterns of activity response to ionic strength at given pH values: the reactions catalyzed by monomeric enzymes are highly modulated by salt, whereas those catalyzed by dimeric enzymes are not. In particular, at the reaction optimum the monomeric form of an enzyme is significantly more active than the dimeric one. 2. The optimum of the reaction catalyzed by a dimeric enzyme is shifted to higher ionic strengths in comparison with that of the reaction catalyzed by a monomeric enzyme. A model is proposed that could explain these results on the basis of the influence of ionic strength on the intramolecular dynamics of the enzyme molecule and its non-specific interactions with polyelectrolytic substrates.
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PMID:Dimerization of deoxyribonuclease I, lysozyme and papain. Effects of ionic strength on enzymic activity. 628 87

Some characteristics of the postirradiation degradation of chromatin in the thymuses of mice were studied. The results proved that the main wave of chromatin degradation becomes evident between 2 and 4 h postirradiation, when considerable amounts of degradation products leach from nuclei during their isolation and are solubilized by lysis of nuclei. Similarly the degradation is manifested in the increase of salt-soluble chromatin fraction as well as of the fractions released from chromatin by various solutions (EDTA, heparin, deoxycholate, alkaline buffer). Later on, within 24 h after irradiation, only little changes in the relative amounts of the degradation products take place. Evidently only a certain thymocyte population is involved. Electrophoretic analyses of DNA fragments from various fractions in native and denatured state demonstrated that chromatin was degraded into nucleosomes and their oligomers by an endonuclease activity. The DNA bears, however, no signs of intranucleosomal regular single-strand fragmentation. This fact makes improbable the participation in this process of DNase I, DNase II and Ca,Mg-dependent endonuclease. No appreciable amount of smaller DNA fragments (products of further degradation of nucleosomes) were found even at 24 h postirradiation interval. Thus the nucleosomes and their oligomers must be considered as the only "long-lived" chromatin fragments in damaged lymphoid cells.
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PMID:On the degradation of chromatin to nucleosomes in the thymocytes of X-irradiated mice. 637 91


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