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 method is described for the extensive purification of acid deoxyribonuclease (acid DNase) and its specific inhibitor from beef liver, the existence of which had been only supported by indirect evidence. By the use of insolubilized acid deoxyribonuclease, eight other proteins interacting with the enzyme have been detected. One of them (molecular weight, 59,000) was identified as responsible for phosphodiesterase activity which is often a contaminant of DNase preparations. Acid DNase (free of phosphodiesterase) and its inhibitor have been obtained as homogeneous proteins, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of acid DNase and its inhibitor are, respectively, 26,500 and 21,500; those of other proteins range from 17,000 to 112,000. The properties of beef liver acid DNase are similar to those described for the enzymes extracted from other sources. The same alteration of DNase kinetics by this inhibitor, as that previously demonstrated with an impure protein has been confirmed; the sigmoidal shape observed at pH 5 for the plot of initial rate versus substrate concentration progressively disappears with increasing pH. We have also demonstrated that RNA, which inhibits the acid DNase through a competitive binding to the catalytic site, is able, like the substrate, to reverse the binding of inhibitor to the enzyme.
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PMID:Protein inhibitor of acid deoxyribonucleases. Improved purification procedure and properties. 0 Mar 96

The results of several tests and the characteristic morphological distribution of the enzymatic activity appeared to be in favor of the validity and specificity of the histochemical lead nitrate technique for alkaline and acid deoxyribonuclease (DNAse) detection. These tests included thermal inhibition, omission of substrate, use of different chemical inhibitors and the reproduction of histochemical staining on Coujard's slides. Most of these results were in conformity with the biochemical data gathered from literature. Topographically selective inhibition of alkaline or acid DNAse by different factors suggested that there might exist two kinds of alkaline or acid DNase--one cytoplasmic and the other one nuclear. The whole histochemical procedure produced relatively small loss of alkaline and acid DNAse activities as verified by biochemical methods.
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PMID:Evaluation of the validity of the histochemical lead nitrate technique for alkaline and acid deoxyribonuclease. 9 2

A comparison of results obtained from studies of the intracellular fractions of the tissues of liver, brain and heart of "young" (1-2 months), "old" (24-27 months) and "senile" (34-37 months) rats showed that the ratios of three enzymes, acid phosphatase, beta-N-acetylglucosaminidase and acid RNase of the liver and heart were very similar and their activities decreased with age. On the other hand, the protein content is the supernatant of the liver, and acid DNase activities in the supernatant of the brain increased significantly with age. When the 24-27 month and 34-37 month old rats were compared, the ratios of the total activities of liver beta-N-glucosaminidase and brain acid DNase in the supernatant and the specific activities of brain beta-N-glucosaminidase in the microsomal fraction increased significantly.
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PMID:Changes in intracellular activities of lysosomal enzymes in tissues of rats during aging. 22 57

Activity of a trypsin-sensitive acid deoxyribonuclease (DNase) inhibitor has been detected in 13- to 21-day-old embryonic chicken brains and in clonal lines of neuroblastoma cells (adrenergic, N1E-115, and neurotransmitter-inactive, N-18) grown for 48 hr after subculture. The activities of purified porcine and bovine spleen DNases were inhibited 60--75% in the presence of the inhibitor, whereas less than 10% inhibition was observed with purified pancreatic DNase. Activities of an acidic DNase and its inhibitor reached maxima in 21-day-old embryonic chicken brain. The proteins were separated by isoelectric focusing and affinity column chromatographic techniques. The pI values of the acid DNase and its inhibitor were 5.4 and 4.2, respectively.
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PMID:Embryonic chicken brain and mouse neuroblastoma cells N1E-115 and N-18 contain an inhibitor of acid deoxyribonuclease. 26 79

The effect of mitogen-induced stimulation in spleen cells and thymocytes of BALB/c mice on acid DNase-activity levels was determined. Increase in thymidine uptake induced by either LPS or ConA in spleen cells and by ConA in thymocytes was invariably accompanied by parallel increase in acid DNase activity. Treatment with mitomycin C (spleen cells) or with an excess dose of ConA (thymocytes) led to sharp reduction in acid DNase activity concomitant with marked drop in thymidine uptake. The results obtained suggest that rise in acid DNase activity takes place during the process of lymphocyte activation by mitogens.
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PMID:Effect of mitogen-induced stimulation on DNase activity in lymphocytes. 31 68

Though DNase does not contain any cysteine residues, incubation of the enzyme with 2-nitro-5-thiocyanobenzoic acid in the presence of Ca2+ at pH values above 7.5 results in an irreversible inactivation of the enzyme. The inactivation also occurs when Ca2+ is replaced by Mg2+, but not in their absence. Amino acid analyses after acid hydrolyses of the completely inactivated ant the native enzymes show no significant differences in composition, including tryptophan and half-cystine residues. However, sodium dodecyl sulfate gel electrophoresis indicates enzyme cleavage by the treatment with 2-nitro-5-thiocyanobenzoic acid. This reagent does not inactivate chymotrypsin and lysozyme, and under conditions where bovine DNase is inactivated, does not inactivate other nucleases such as ribonuclease, snake venom phosphodiesterase, and spleen acid DNase. However, it inactivates malt DNase and can, therefore, be considered a specific inhibitor of DNase I. The inactivation kinetics is pseudo-first order, resembling Michaelis-Menten, with an affinity constant of 16.7 mM. It is the cyano group, not the thionitrobenzoic acid of 2-nitro-5-thiocyanobenzoic acid that reacts to form cyano-DNase.
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PMID:Inactivation of bovine pancreatic DNase by 2-nitro-5-thiocyanobenzoic acid. I. A novel inhibitor for DNase I. 48 54

The 5'-terminal dinucleotides released by five deoxyribonucleases (spleen acid DNase, snail acid DNase, pancreatic DNase, Escherichia coli endonuclease I and crab DNase) have been determined on E. coli DNA (51% dG & dC) digests having different average sizes (Pn) in the range 50 to 10. It has been shown that the composition of the 5'-terminal dinucleotide (a) is independent upon the degradation level, at least in the range explored; (b) is strongly different from the composition of E. coli DNA doublets, these differences being characteristic for each enzyme; (c) is very significantly different from the statistical composition of 5'-terminal dinucleotides, as calculated from the composition of 5'-terminal and penultimate nucleotides. A calculation of the statistical composition of the trinucleotides split by each enzyme, using the 3'-terminal nucleotide data in conjunction with the 5'-terminal dinucleotide results provided a qualitative "specificity spectrum" for each enzyme.
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PMID:The specificity of five DNAases as studied by the analysis of 5'-terminal doublets. 80 Sep 85

The biochemical correlates of droplet formation in renal inner medullary cells of potassium-deficient rats were studied. An increase in the activities of five hydrolytic enzymes typical of lysosomes was associated with an increase in the number and size of droplets observed during progressive potassium depletion. Acid phosphatase activity increased 7-fold whereas beta-glucuronidase, beta-galactosidase, cathepsin, and acid DNase increased 2- to 4-fold in medullary homogenates at 25 days of depletion. Following potassium repletion the activities returned to normal at a rate dependent upon the duration of potassium depletion. The decreases in enzyme activities were associated with a concomitant rapid disappearance of the droplets from medullary cells. Protein synthesis for new droplet enzyme formation was studied by measuring the rate of [14C]leucine incorporation into protein in medullary slices. The rate increased at 1 day of depletion and reached a maximum which was 139 per cent higher than control after 7 days of depletion. In droplets isolated from medullary tissue during progressive potassium depletion the rate of protein labeling with [14C]leucine and acid phosphatase specific activity increased in parallel. When droplet proteins were separated by gel electrophoresis, acid phosphatase activity was detected in a protein band which had been labeled with [14C]leucine, thereby suggesting new enzyme protein formation. The increase in enzyme and protein synthesis and a previously demonstrated increase in phospholipid synthesis and membrane formation indicate that potassium depletion induces specific alterations in renal inner medullary cell metabolism which result in increased lysosome formation.
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PMID:Formation of renal medullary lysosomes during potassium depletion nephropathy. 83 28

Properties of type 7 adenovirions in lysosomes of HeLa cells were studied 12 hr postinfection. Viral particles were transferred to the lysosomes very quickly after initiation of penetration, i.e., after 10 min of incubation at 37 degrees. No morphological modification of the virion was detected for 6 hr postinfection. However, by 12 hr postinfection, the virion was no longer recognizable. Most of the virus remained infectious for 2 hr, whereas after 12 hr the infectivity was abolished. Soon after the adsorption of the virus on the cell membrane at 4 degrees, the viral DNA in the virion became sensitive to pancreatic DNase, and this sensitivity increased during the first 2 hr of incubation at 37 degrees. This result suggests that some modification in the architecture of the virion occurred before transfer to the lysosomes. The adenovirus 7 (Ad 7) DNA extracted from the lysosomes appeared intact for 6 hr postinfection and was found to cosediment at 34 S with the Ad 2 DNA marker. Comparable activities of free acid phosphatase were found in lysosomes isolated from uninfected control cells and from infected cells. In in vitro experiments, lysosomal acid DNase and pancreatic DNase were shown to degrade Ad 7 DNA at similar rates; however, in vivo, intralysosomal Ad 7 DNA was only partially sensitive to lysosomal DNase.
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PMID:The fate of type 7 adenovirions in lysosomes of HeLa cells. 84 71

Collagenase perfusion of the liver followed by pronase treatment of the cell suspension thus obtained gave a quantitative recovery of viable nonparenchymal liver cells (NPC). From these NPC, Kupffer (K) cells can be purified by attachment to tissue culture dishes. Tail vein injection of carbon 1-2 h before liver perfusion permitted stepwise calculation as well as visualization of carbon-containing K cells. When these K cells have been put into tissue culture medium with serum and incubated overnight, they exhibit typical macrophage characteristics. Phase-contrast and transmission electron microscopy showed typical macrophage morphology and scanning electron microscopy revealed well-spread cells with cytoplasmic projections and ruffled membranes. Endocytosis studies using radioactive colloidal gold and inert latex particles also indicated that these cells are highly active in pinocytosis and phagocytosis. Further characterization of K cells is the identification of Fc receptor on their membranes. Studies on lysosomal enzymes showed that purified K cells possess higher specific activities in beta-glucuronidase, acid DNase, and cathepsin D than in purified parenchymal cells.
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PMID:Mass isolation and culture of rat kupffer cells. 109 Jun 96


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