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)

Hepatitis B core antigen (HBcAg) particles, approximately 27-28 nm in diameter and rho = 1.30-1.35 g/cm3, were purified from the liver of a chimpanzee experimentally infected with hepatitis B virus (HBV) while under cyclophosphamide treatment. The purified HBcAg particles incorporated radioactive deoxythymidine triphosphate. The product was precipitable by trichloroacetic acid and sensitive to DNase, but resistant to digestion by RNase. The reaction required four deoxyribonucleosise triphosphates- dATP, dCTP, dGTP and dTTP. Exogenous template did not enhance the reaction. From these findings, it was suggested that HBcAg particles purified from the HBV-infected chimpanzee liver contained DNA polymerase and endogenous DNA.
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PMID:Hepatitis B core particles with endogenous DNA polymerase activity from chimpanzee liver. 68 Nov 46

When pancreatic DNase I is used as a specific biochemical reagent in the preparation of nuclear ribonucleic acids or nuclear proteins, freedom from contaminating ribonucleases or proteases is an important property of the enzyme preparation. A simple one-step procedure has been developed to effect complete removal of trypsin, chymotrypsin, and chymotrypsinogen by a combination of affinity chromatography and salting-out adsorption on lima bean protease inhibitor coupled to Sepharose (a column (0.9 X 60 cm) operated in series with a regeneratable 1-ml bed). Commercial preparations of DNase (about 10 mg) give a quantitative yield of the enzyme that is protease-free as evidenced by full stability for more than 10 days at pH 8 and 37 degrees C even in the absence of the protecting action of Ca2+. Removal of the last traces of RNase has been accomplished by affinity chromatography on a column (0.4 X 72 cm) of 5'-(4-aminophenyl-phosphoryl)-uridine 2'(3')-phosphate-Sepharose; the product is a highly active DNase that gives no detectable hydrolysis of RNA by assay on radioactive substrates.
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PMID:Preparation of protease-free and ribonuclease-free pancreatic deoxyribonuclease. 70 Dec 44

By the calcium technique, intact DNA of bovine adenovirus type 3 (BAV3) was found to transform A31 cells, a clone of BALB/3T3. Transforming activity was resistant to RNase and Pronase but sensitive to DNase. The efficiency of transformation was approximately 5 to 10 foci per mug of DNA. Attempts were also made to test for transforming activity of BAV3 DNA fragments prepared with restriction endonucleases EcoRI and HindIII. The activity was found to associate exclusively with the EcoRI D fragment mapped in the region of 3.6 and 19.7 units (molecular weight, 3.9 x 10(6)). No transformation could be obtained with three HindIII fragments, J, E, and B, located at the left-hand end of the BAV3 genome. However, the enzymatic joining of J and E fragments (0 to 11.9 map units) with a ligase restored the transforming activity. These results suggest that all the genetic information of BAV3 required for transformation is located in the region between 3.6 and 11.9 units on the viral genome. Some properties of A31 cells transformed by BAV3 DNA EcoRI D fragment (TrD) and the ligated DNA of HindIII J and E fragments (TrJE), as well as those transformed by whole BAV3 DNA (Tr), were examined. As compared to untransformed A31 cells, all the transformed cell lines tested showed rapid growth, high saturation densities, and anchorage-independent growth. Moreover, they contained BAV3-specific T antigen and induced tumors in adult nude and BALB/c mice. These properties of Tr, TrD, and TrJE lines were similar to those of BAV3-transformed cells.
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PMID:Biochemical studies on bovine adenovirus type 3. IV. Transformation by viral DNA and DNA fragments. 70 48

DNA-dependent RNA polymerase class C (or III) has been solubilized from either uninfected or adenovirus-2-infected HeLa cells and purified by chromatography on phosphocellulose, DNA-cellulose, CM-Sephadex and DEAE-Sephadex. The last column separated the enzyme into three forms CI, CII and CIII, which were completely free of RNA polymerases class A and B and of DNase and RNase. The total and the relative amount of these different enzyme C forms did not vary whether purified from uninfected or infected cells. Irrespective of the stage of purification, the three enzyme forms transcribed deproteinized adenovirus-2DNA very efficiently. This transcription was highly sensitive to elevated ionic strength (especially in the presence of Mg2+) and was accompanied by continuous reinitiation as shown by adding poly(rI), a potent inhibitor of initiation. In addition heparin-resistant initiation complexes could be formed at elevated temperature. The RNA synthesized in vitro on deproteinized intact adenovirus-2 DNA by the different forms of RNA polymerase class C, has been characterized. Analysis of the transcripts by gel electrophoresis, RNA self-annealing, hybridization to separated adenovirus-2 DNA strands and to restriction endonuclease (BamHI, HindIII), adenovirus-2 DNA fragments have demonstrated that restriction endonuclease (BamHI, HindIII), adenovirus-2 DNA fragments have demonstrated that the various regions of the adenovirus-2 genome were randomly transcribed. In addition, hybridization of RNA transcripts labelled at their 5' end by either [gamma32P]ATP or [gamma-32P]GTP indicated that not only elongation but also initiation occurred randomly through the entire adenovirus-2 genome, irrespective of the form of the enzyme and of the origin of the cells (normal or infected). The results are discussed in terms of the components which are possibly involved in specific transcription.
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PMID:Transcription in vitro of adenovirus-2 DNA by RNA polymerases class C purified from uninfected and adenovirus-infected HeLa cells. 71 Apr 51

After continuous 3H-TdR infusion in vivo or incubation with 3H-TdR in vitro human blood lymphocytes were examined by light-microscopic and electron-microscopic autoradiography. Using relatively long autoradiographic exposure times (50--300 days) not only nuclear but also cytoplasmic labelling was visualized, the cytoplasmic label being present in up to 96% of the cells. The cytoplasmic label was predominantly associated with the mitochondria and was removed from the cells nearly completely by treatment with DNase but not with RNase or cold perchloric acid. It is concluded that this cytoplasmic label mainly represents 3H-TdR incorporated into mitochondrial DNA which is continuously renewed in an average turnover time of 14 days or less. This value is compatible with a turnover time of 11 days for mitochondrial DNA in mammalian cells reported in the literature.
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PMID:Labelling of human resting lymphocytes by continuous infusion of [3H]thymidine. I. Characterization of cytoplasmic label. 72 7

The DNA in isolated chloroplasts was visualized by the fluorescent probe 4'6-diamidino-2-phenylindole (DAPI). When excited with light of 360 nm, the DNA-DAPI complex fluoresces brilliantly at 450 nm. Nuclei also fluoresce but their nucleoli do not. RNase and Pronase treatment of chloroplasts did not affect the fluorescence but both pre- and posttreatment of DAPI-stained chloroplasts with DNase specifically destroyed the fluorescence. DNA-DAPI complexes in the chloroplasts show up as bright dots. These are distributed uniformly within the chloroplast except for the outer margins. The fluorescent dots can be seen at different focal levels. The number of DNA dots is roughly proportional to chloroplast area which, in turn, is a function of leaf size. The number of fluorescent dots also gave the impression that large leaves with large chloroplasts contain more chloroplast DNA than nuclear DNA.
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PMID:Visualization by fluorescence of chloroplast DNA in higher plants by means of the DNA-specific probe 4'6-diamidino-2-phenylindole. 73 Jul 64

Ovarian hormones, particularly 17 beta-estradiol, have important effects on body fat levels in rats, but it is not known whether 17 beta-estradiol can act directly on various fat depots to affect adiposity or whether these effects are entirely indirect (e.g. via food intake, exercise, or various metabolic actions). We have found high affinity, estrogen-specific macromolecular binding of 17 beta-[3H]estradiol in the cytoplasmic fraction of adipose tissues from ovariectomized rats. Saturation analysis indicates a Kd of 7.4 X 10(-10) M, and binding is inhibited by unlabeled 17 beta-estradiol or 11 beta-methoxy-17-ethynyl-1,3,5(10)-triene-3,17beta-diol (R2858) but not by progesterone, 5 alpha-dihydrotestosterone, or cortisol. 17 beta-[3H]Estradiol binding is virtually abolished by incubation with pronase but not with DNase or RNase, indicating that the binding macromolecule is probably a protein. Binding is seen in all adipose tissues studied, including abdominal, sc, and brown fat. Binding site concentration is highest in parametrial fat pads, followed by retroperitoneal, brown, omental, and inguinal depots. Binding is also seen in the cytoplasmic fraction of isolated parametrial adipocytes. These data indicate that the various adipose tissues might be estrogen target tissues in rats. Therefore, it is possible that estrogenic effects on body weight and composition could be mediated in part by direct estrogen action on adipose tissues.
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PMID:Cytoplasmic 17 beta-[3H]estradiol binding in rat adipose tissues. 74 11

Precursor mRNA (pre-mRNA) was extracted from erythroid enriched bone marrow cells of the rabbit by the methods of Georgiev and Mantieva modified by Markov and Arion and of Holmes and Bonner, respectively. Density gradient centrifugation, base analysis and the effects of alpha-amanitin and actinomycin D on the synthesis of the cellular RNA showed signs of degradation in the rRNA-free 85 degrees C-fraction of the preparation according to Georgiev and Mantieva and a substantial rRNA contamination of the 65 degrees C-fraction. This RNA-fraction as well as the total RNA-preparation extracted according to Holmes and Bonner was purified from rRNA by affinity chromatography on poly(U)-Sepharose. Poly(A)+-RNA of all size-classes, among it a substantial amount of high molecular weight RNA (greater than 45 S), was isolated by this purification procedure. Especially the extraction according to Holmes and Bonner yields high molecular weight material but the critical step of this procedure often resulting in degradation of the RNA is the DNase treatment of the heavily DNA-contaminated total RNA-preparation either due to RNase contamination of the DNase or to the existence of RNase in the less intensive deproteinized RNA. The investigated cellular system is characterized by a very intensive rRNA synthesis which is typical for cells in the early stages of hematopoiesis. In contrast to investigations with purified RNA-polymerases and subcellular systems, but in accordance with data of in vivo experiments, alpha-amanitin inhibits both the pre-mRNA and the pre-rRNA synthesis.
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PMID:Pre-mRNA from erythroid enriched bone marrow cells of the rabbit. II. Characterization of pre-mRNA isolated by phenol extraction and poly(U)-Sepharose chromatography. 74 68

Solid media were used to determine which extracellular hydrolytic enzymes are produced by Phytophthora parasitica; P. parasitica var. nicotianae, races 0, 1, and 3; and several other Phytophthora spp. Most isolates produced RNase, DNase, phosphatase, lipase, and cellulase uniformly. All race 3 isolates of P. parasitica var. nicotianae exhibited protease activity on a medium containing gelatin, while only 33 and 60% of the race 0 and 1 isolates, respectively, and 14% of the P. parasitica isolates did so. Addition of sorbose to this medium enabled the detection of protease activity by most of the isolates. Amylase activity, measured in the culture fluid, was higher in race 3 than in races 0 or 1 of P. parasitica var. nicotianae and P. parasitica.
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PMID:An examination of enzyme production of Phytophthora spp. on solid and liquid media. 75 80

The mixing of two histoincompatible human lymphocyte cell lines generated the release of a soluble factor which was capable on non-specifically enhancing the in vitro immune response of normal mouse spleen cells against sheep erythrocytes. The mediator was secreted into the supernatant of the allogeneic cell cultures within 24 h of cultuvation. The human enhancing factor (HEF) must be added to assay cultures on day 2, of a 5-day culture period, for its activity to be manifest. HEF was resistant to DNase, RNase and heating at 56 degrees for 30 min, but was inactivated by exposure to protease or elevated temperature (80 degrees for 30 min). The molecular weight of HEF, purified by ammonium sulphate fractionation, followed by Sephadex gel filtration, DEAE-cellulose chromatography and SDS-polyacrylamide gel electrophoresis, was approximately 38,000 Daltons.
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PMID:Partial characterization of an immunoenhancing factor from allogeneic human lymphocyte cell lines. 76 66


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