Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.1 (DNase)
 7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paper describes a method for isolating alkaline ribonuclease from the culture liquid Bacillus subtilis KP 349 which involved: submerged cultivation of the producer on complex and synthetic nutrient media with optimized RNase activity, acid treatment of the total culture liquid, and filtration through perlite. Further treatment may include either spray drying of the culture liquid filtrate or its concentration in a vacuum evaporator, dialysis of the concentrate against distilled water, and dialyzate lyophilization. As a result, commercial RNase preparations with activities of 30--60 thous. and 160--300 thous. units/g, respectively, were obtained. The enzyme purification was carried out by chromatography and rechromatography on phosphocellulose columns. The resultant RNase of Bac. subtilis had a specific activity of 41--44 thous. units/mg protein, contained no nonspecific phosphodiesterase, DNase, acid or alkaline phosphomonoesterases.
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PMID:[Preparation of extracellular ribonuclease from Bacillus subtilis]. 10 17

Mouse fibroblasts contain a macromolecular binding component (receptor) which binds glucocorticoids specifically and with high affinity. This study shows that there are three different cellular forms of bound receptor and that it is experimentally possible to markedly alter the subcellular distribution of these three forms. Cells incubated with (3H)triamcinolone acetonide were broken after hypotonic shock and a 7000g hypotonic supernatant was obtained; the pellet was extracted with 0.3 M KCl, yielding a nuclear extract; the remaining pellet was resuspended in water, sonicated, and assayed for "nuclear residual" (i.e., nonextractable) radioactivity. If whole cells are incubated at 0 degrees in a growth medium, almost all of the bound steroid is located in the hypotonic supernatant fraction. Incubation at 37 degrees produces a shift of the steroid-bound macromolecule into the nuclear extractable form, while omission of glucose and addition of KCN at 37 degrees markedly increase the nuclear residual form at the expense of both the nuclear-extractable and supernatant forms. Since DNase treatment of chromatin liberates a soluble steroid-receptor complex, we believe that the nuclear residual form may be steroid-receptor complex tightly bound to chromatin. We propose a model suggesting that an energy-requiring process is required to generate free receptor from the chromatin complex to complete the normal cellular recycling system.
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PMID:Subcellular distribution of glucocorticoid receptors in mouse fibroblasts. 16 30

The injury degree of lysosomes isolated from the rat liver under low temperature conditions was studied with respect to nonsedimented hydrolases activities (acid RNases, DNase, phosphatase, cathepsins) taken as a biochemical criterium of lysosomal membrane stability. The lysosomal fraction was resuspended in 0.15 M NaCl solution and frozen in the liquid N2 vapours up to --30 degrees C. According to the thermographic analysis data the samples were thawed and studied at different stages of cooling. The activity of the studied hydrolases was established to increase most considerably during the water crystallization period and at the NaCl eutectic point. Hydrolytic enzymes release from lysosomes proved to be dependent on the thawing rate and NaCl concentration. The obtained data indicate to the importance of concentration factors in lysosomal membrane cryoinjury.
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PMID:[Importance of concentration factors in cryoinjury of lysosomes]. 17 54

The level of the non--sedimentating activity of acid hydrolases (deoxyribonuclease, phosphatase, cathepsins) and electron microscopy of lysosomes has been studied after freezing to --30 degrees, --70 degrees, --140 degrees and --196 degrees. It has been found that enzyme solubilistion and lysosome ultrastructure distortion are mostly marked in the temperature range between 0 degrees and --30 degrees C. Additional membrane damage is observed in the temperature range from --140 degrees to --196 degrees C. It is suggested that not only physico-chemical changes during phase transitions of free water in the freezing medium but also recrystallization processes and the freezing-out of water structurally bound with membranes may contribute to mechanism of lysosome cryoinjury.
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PMID:[Effect of deep freezing on isolated rat liver lysosomes]. 20 67

Epithelioid liver cells were established in culture from rats sacrificed 10 to 18 weeks after the administration of the hepatocarcinogen diethylnitrosamine in their drinking water. After approximately 3 months in vitro, more than half the cells propagated from rats that developed hepatocellular carcinomas had bean-shaped, acentrically displaced nuclei with large juxtanuclear homogeneous appearing areas resembling the hyalin or Mallory bodies in the livers of chronic alcoholics. These abnormalities were not seen in the livers of origin, but were retained in the carcinomas that formed after the cultured cells containing such juxtanuclear hyalin inclusions were inoculated into young rats or nude (i.e., thymusless) mice; these features persisted upon reestablishment and continuous passage of the tumor cells in culture. The cells were further characterized by their karyotypes and their growth properties in liquid media and soft agar. By transmission electron microscopy the hyaline bodies in the culture tumor cells were shown to consist of a disorganized meshwork of filaments. Examination by incubating cells with cytochalasin B and by using antiactin and anti-DNase antisera as indirect immunofluorescence probes also revealed a disturbance in the cytoskeleton.
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PMID:In vitro demonstration of Mallory body formation in liver cells from rats fed diethylnitrosamine. 20 30

The effects of 25 to 75 volume-% ethanol on conformation of human serum alpha1-acid glycoprotein, human serum alpha1-antitrypsin, pancreatic deoxyribonuclease I, porcine pepsinogen, the "Kunitz" trypsin inhibitor from soybeans, and oxidized as well as reduced and S-carboxymethylated ribonucleases were tested by the circular dichroism (CD) probe. It was found that 25 volume-% ethanol had a slight effect, whereas 50--75 vol.-% alcohol significantly altered the conformation. The tertiary structure was perturbed and the polypeptide main chain was reorganized into new conformations of higher helix and beta-structure contents than in the native state. Comparison of the various proteins showed that the degree of reorganization depended chiefly on the cross-linking of the main chain by disulfide bridges. While the unfolded ribonucleases were refolded by 25 vol.-% ethanol into ordered conformations, the native ribonuclease and alpha1-antitrypsin was more sensitive to 25 vol.-% ethanol than the conformation of alpha1-acid glycoprotein, pepsinogen, and soybean trypsin inhibitor. Almost complete restoration of the native conformation was achieved by diluting the alcohol-containing solutions with water or by dialysis against water or buffer solutions. However, the renaturation depended on the time of contact with alcohol and on the temperature at which the alcohol-containing solutions were kept.
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PMID:Circular dichroism studies on the effects of ethanol on the conformation of alpha1-acid glycoprotein, alpha1-antitrypsin, deoxyribonuclease, pepsinogen, soybean trypsin inhibitor and unfolded ribonucleases. 30 38

Spindle pole bodies (SPBs) were isolated from the yeast Saccharomyces cerevisiae by an adaptation of the Kleinschmidt monolayer technique. Spheroplasts prepared from the cells were lysed on an air-water interface. Spread preparations were picked up on grids, transferred to experimental test solutions, and prepared for whole-mount electron microscopy. Using purified exogenous tubulin from porcine brain tissue, the isolated SPBs were shown to nucleate the assembly of microtubules in vitro. Microtubule growth was directional and primarily onto the intranuclear face of the SPB. Neither the morphology nor the microtubule-initiating capacity of the SPB was affected by treatment with the enzymes DNase, RNase, or phospholipase although both properties were sensitive to trypsin. Analysis of SPBs at various stages of the cell cycle showed that newly replicated SPBs had the capacity to nucleate microtubules. SPBs isolated from exponentially growing cells initiated a subset of the yeast spindle microtubules equivalent to the number of pole-to-pole microtubules seen in vivo. However, SPBs isolated from cells in stationary phase and therefore arrested in G1 nucleated a number of microtubules equal to the total chromosomal and pole-to-pole tubules in the yeast spindle. This may mean that in G1-arrested cells, the SPB is associated with microtubule attachment sites of the yeast chromatin.
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PMID:Nucleation of microtubules in vitro by isolated spindle pole bodies of the yeast Saccharomyces cerevisiae. 35 37

In this paper evidence is provided that one of the protein components of the water-soluble fraction of the calf lens binds specifically to deoxyribonuclease I (DNAse I). On the basis of this property, the polypeptide could be purified by applying DNAse I affinity chromatography. Concomitantly a protein of Mr55000 and a rather large amount of alpha-crystallin copurify with this polypeptide, which has a molecular weight of 42000. Highly purified 42000-Mr protein was also obtained by extraction of the water-insoluble fraction of the calf lens with 2-([tris(hydroxymethyl)methyl]amino) ethanesulfonic acid followed by gel filtration. Amino acid analyses, peptide mapping and electron microscopy show that the protein obtained from both lens fractions is identical to non-muscle actin. Furthermore the amino acid composition of the 55000-Mr protein is identical to hog stomach skeletin and very similar to calf brain desmin.
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PMID:Actin in mammalian lens. 44 81

Telomeric heterochromatin can be demonstrated in Allium cepa chromosomes when root tip squashes are subjected to a C-banding procedure (treatment with saturated barium hydroxide for 10 min, followed by 1 h in phosphate buffer at 60 degrees C). Acridine orange (A0) staining indicated that the chromosomal DNA was denatured by the alkaline treatment and that it renatured within the first 3-7 min in the hot buffer. The DNA of the telomeres reannealed somewhat faster than the rest of the chromosomal DNA, but the AO staining suggested that all chromosomal DNA was double stranded after 7 min in buffer. Digestion of the chromosomes with a single strand specific nuclease, DNase S1, followed by Feulgen staining, demonstrated that the AO staining gives a somewhat misleading picture of the extent of DNA denaturation and renaturation. The S1 nuclease results showed that the chromosomal DNA was completely denatured by the alkaline treatment, but that a fraction of the DNA reannealed during the deionized water wash that preceded the incubation in hot buffer. Neither controls nor chromosomes subjected to the complete C-banding procedure were affected by S1 nuclease digestion, demonstrating that virtually all of the chromosomal DNA was double stranded both before and after the C-banding process. These results, along with the fact that the appearance of the bands was unaffected when the buffer incubation was performed at high (80 degrees C) or low (40 degrees C) temperature, indicated that differential DNA denaturation and renaturation is unlikely to be responsible for C-banding in this species.
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PMID:Differential rates of DNA denaturation and renaturation in situ in relation to the C-banding of Allium cepa chromosomes. 75 82

Adenovirus type 5 'cores' prepared by heating in the presence of deoxycholate and partially purified on a glycerol density gradient could be visualized as roughly isometrical particles with a condensed centre from which twisted filaments or loops of DNA emanated. This compact structure was readily dispersed by spreading on distilled water or by treatment with EDTA, Nonidet, DNase or trypsin. Spreading with Nonidet was particularly effective in unfolding the cores and revealing long filaments about 100 A thick presumably of the virus nucleoprotein. Subunits (about 30 to 60 A in diam.) could be seen free in the DNase-treated cores, suggesting a particulate nature of one or both of the core proteins.
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PMID:Electron microscopy of adenovirus cores. 80 87


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