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)

A deoxyribonuclease inhibitor has been purified from KB cells by chromatography on single-stranded DNA-cellulose. Polyacrylamide gel electrophoresis showed the purified preparation to contain two major polypeptides in sodium dodecyl sulfate, with molecular weights of 72,000 and 65,000, but only one major band (with a molecular weight of approximately 140,000) after electrophoresis under nondenaturing conditions. The protein inhibits the hydrolysis of single-stranded DNA by KB DNase, DNase I, DNase II, and nuclease S1, but has no effect on the hydrolysis of double-stranded DNA by these enzymes. The inhibitor causes a reduction in the rate of hydrolysis of DNA by the deoxyribonuclease, probably by reducing the effective concentration of substrate.
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PMID:A deoxyribonucleic acid binding protein from KB cells which inhibits deoxyribonuclease activity on single-stranded DNA. 42 57

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

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

Acid deoxyribonuclease (EC 3.1.4.6) (DNase) from young (16 days of incubation) and old (1.5 years) chick cerebral hemispheres was purified to apparent homogeneity. Throughout the purification schedule, the behavior of "young" and "old" enzymes was similar. However, the specific activity of the purified enzyme from old brain was only one-tenth that of young enzyme. Polyacrylamide gel electrophoresis of the purified acid DNase gave a single band. Antisera against both "young" and "old" enzyme were raised and double immunodiffusion experiments revealed cross-reaction of young antigen with old antiserum and vice versa, although precipitin bands with young antigen against young antiserum and old antigen against old antiserum were more sharp. Both young and old acid DNase preparations showed an apparent molecular weight of 62,000 and many other properties like heat stability, effect of various exogenous compounds like Hg2+, Zn2+, Mg2+, etc., were also similar. The old enzyme showed slightly higher Km and decreased Vmax compared with the young enzyme. Dansylation of N-terminal amino acids and their analysis following tryptic digestion of both "young" and "old" acid DNase revealed a similar pattern. Immunotitration experiments showed that the old enzyme requires more antiserum prepared against "young" enzyme to achieve 50% inactivation, thus pointing out the presence of completely or partially inactive molecules in "old" acid DNase preparation. Circular dichroism spectra of the enzyme preparations indicated that the "old" acid DNase molecules are more rigid and have more alpha-helical structure, compared with the "young" enzyme. From these data, it is suggested that the reduction in the specific activity of old acid DNase may be, apart from other possibilities, due to conformational changes in the enzyme molecules.
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PMID:Age-dependent conformational changes in acid deoxyribonuclease of chick brain. 619 64

An acid deoxyribonuclease has been purified from rat small intestinal mucosa by a procedure including ammonium sulfate fractionation, chromatographies on DEAE-cellulose, CM-cellulose and SE-Sephadex and finally isoelectric focusing. Polyacrylamide gel electrophoresis of the purified enzyme preparation showed one major and two minor bands, and the enzyme activity corresponded to one of the minor bands. The enzyme preparation was free of contaminating DNase I, DNase III, alkaline RNase, acid and alkaline phosphatases and nonspecific phosphodiesterase, but slight activities of DNase IV and acid RNase were detected. The enzyme did not require divalent cations for activity, had a pH optimum of 4.5 in 0.33 M sodium acetate buffer, and had an optimum temperature of 50 to 60 degrees C when assayed for 30 min. The rate of hydrolysis of native DNA was about 2.5-fold faster than that observed with denatured DNA. Its molecular weight was found to be 9.0 +/- 0.1. The enzyme catalyzes the endonucleolytic cleavage of native and denatured DNA, yielding oligonucleotides which have an average chain length of about 7, and which contain 3'-phosphoryl termini. The mode of action of the enzyme is double-strand scission.
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PMID:Purification and properties of an acid deoxyribonuclease from rat small intestinal mucosa. 663 Jan 62