Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.25.1 (deoxyribonuclease)
 1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A standardized bioassay for transfer of Fv-1 gene-specific resistance to N-tropic and B-tropic murine retroviruses was developed using X plaque reduction in SC-1 (Fv-1-) cells inoculated with virus. Testing of subcellular fractions of restrictive cells showed that the resistance transfer activity was present in the cytoplasmic (microsomal and cytosol) fractions. The activity of the cytoplasmic extract was destroyed by treatment with ribonuclease, but not with deoxyribonuclease or proteases. RNA prepared by phenol-chloroform extraction of mouse tissues, including embryos and livers of weanling mice, transferred Fv-1 locus-specific resistance into DEAE-dextran-treated SC-1 cells. The activity of isolated RNA preparations against virus of the appropriate host-range type has been demonstrated to correspond to the Fv-1 genotypes of the cell sources. The specific transfer of resistance with cellular RNA was effective within a 5- to 6-h period from 2 h before to 4 to 5 after virus infection. Sucrose gradient centrifugation of the RNA showed that the activity sedimented as a broad peak, with an apparent maximum in the 22S region. Affinity chromatography of whole-cell RNA on polyuridylic acid-Sepharose tended to separate more activity into the polyadenylic acid RNA fraction than the non-polyadenylic acid RNA fraction. Except for the reciprocal inhibitory activity for the two host-range virus types, the RNAs of Fv-1n and Fv-1b specificities showed similar properties in all aspects studied.
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PMID:Transfer of Fv-1 locus-specific resistance to murine N-tropic and B-tropic retroviruses by cytoplasmic RNA. 21 Dec 61

Vibrio cholerae phage PL 163/10, belonging to Mukherjee's group I, gave clear plaques with surrounding halos of overall diameters varying between 1 to 4 mm when plated on a lawn of host V. cholerae OGAWA 154. It was fairly stable in the PH range 6-11. Its thermal inactivation was characterised by half lives of 39, 12, 4.5 and 1.0 minutes at 55, 60, 65 and 70 degree C respectively. The thermodynamic parameters deltaH, deltaF and deltaS were determined at these temperatures. The phange was resistant in vitro to sodium deoxycholate, trytrypsin, chloroform, robonuclease, deoxyribonuclease, Tris, Tris + EDTA, Tris + lysozyme and phosphate buffer but rapidly inactivated by sodium lauryl sulfate. Adsorption of this phage was biphasic. Intracelllular growth of the PL 163/10 phage was characterised by an eclipse period of 13 minutes, latent period of 31 minutes, rise period of 29 minutes and an average burst size of about 10 PFU/cell. This phage possessed a hexagonal head 106 plus or minus 18 x x 740 plus or minus 27 A without any tail structure.
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PMID:Properties of the cholera phage PL 163/10. 23 74

Heat-stable enterotoxin (ST) produced by porcine strains of enterotoxigenic (ENT+) Escherichia coli has been purified to apparent homogeneity by sequential ultrafiltration, acetone fractionation, preparative gel electrophoresis, diethylaminoethyl Bio-Gel A ion-exchange chromatography, and Bio-Gel P-10 gel filtration. The enterotoxin, purified more than 1,500-fold, exhibited a molecular weight of 4,400, as determined by both sodium dodecyl sulfate-gel electrophoresis and gel filtration. A molecular weight of 5,100, representing 47 residues, was calculated from amino acid analysis data. The amino acid content was distinctive, with an unusually high proportion of cystines and few hydrophobic amino acids. A single amino-terminal residue, glycine, was observed. Purified ST was stable to heating (100 degrees C, 30 min) and did not lose biological activity after treatment with Pronase, trypsin, proteinase K, deoxyribonuclease, ribonuclease, and phospholipase C. Periodic acid oxidation and several organic solvents (acetone, phenol, chloroform, and methanol) had no effect on the biological activity of ST. Further, purified ST was stable to acid treatment at pH 1.0 but lost biological activity at pH values greater than 9.0. Neither lipopolysaccharide nor lipid contamination was evident in purified preparations. A characteristic absorption spectrum was observed during the course of the purification, which shifted from a maximum at 260 nm in crude preparations to 270 nm for the purified toxin. Antiserum obtained from rabbits immunized with ST or ST coupled to bovine serum albumin neutralized the action of the enterotoxin in suckling mice; however, passive hemagglutination and hemolysis titer assays suggested that ST is a poor antigen.
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PMID:Purification and chemical characterization of the heat-stable enterotoxin produced by porcine strains of enterotoxigenic Escherichia coli. 34 81

The fate of [3H]DNA from Streptococcus sanguis str-r43 fus-s donors in [14C]S. sanguis str-s fus-r1 recipients was studied by examining the lysates prepared from such recipients at various times after 1 min of exposure to DNA. The lysates were analyzed in CsCl and 10 to 30% sucrose gradients; fractions from the gradients were tested for biological activity and sensitivity to nucleases, subjected to various treatments and retested for nuclease sensitivity, and run on 5 to 20% neutral and alkaline sucrose gradients. The results demonstrate that donor DNA bound to S. sanguis cells in a form resistant to exogenous deoxyribonuclease is initially single stranded and complexed to recipient material. Donor DNA can be removed from the complex upon treatment of the complex with Pronase, phenol, or isoamyl alcohol-chloroform. Within the complex, donor DNA is relatively insensitive to S1 endonuclease but can regain its sensitivity by treatment with phenol. With time the complex moves as a whole to associate physically with the recipient chromosome. After a noncovalent stage of synapsis, donor material is covalently bonded to and acquires the nuclease sensitivity of recipient DNA, while donor markers regain transforming activity and become linked to resident markers.
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PMID:Fate of homospecific transforming DNA bound to Streptococcus sanguis. 64 Oct 7

When isolated human fibroblast lysosomes are incubated with 4 microM [32P]phosphate at pH 7.0, orthophosphate is transported into lysosomes and is rapidly incorporated into low and high molecular weight products. We have characterized the high molecular weight (HMW) lysosomal material into which [32P]phosphate is incorporated and have found it to consist of long chains of inorganic polyphosphate based on the following observations. 1) greater than 97% of HMW 32P-lysosomal material is converted to [32P]orthophosphate when incubated with 1 N HCl for 20 min at 100 degrees C. 2) Incubation of HMW 32P-lysosomal material at pH 7.0 and 65 degrees C for 96 h results in the formation of [32P]trimetaphosphate, which is known to be produced only from linear chains of polyphosphate under these conditions. 3) HMW 32P-lysosomal material is resistant to degradation by proteinase K, ribonuclease, and deoxyribonuclease and extracts into the aqueous phase during phenol/chloroform extractions. 4) HMW 32P-lysosomal material displays heterogeneous mobility on polyacrylamide gels with most chains ranging in length from 100 to at least 600 phosphate residues. 5) HMW 32P-lysosomal material is partially hydrolyzed under alkaline conditions to yield a continuous ladder of polyphosphate species differing by one or several residues in length on polyacrylamide gels.
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PMID:Incorporation of [32P]orthophosphate into long chains of inorganic polyphosphate within lysosomes of human fibroblasts. 174 Apr 14

A protein kinase which is intimately associated with equine herpesvirus (equine abortion virus) was found by using adenosine triphosphate-gamma-(32)P as a phosphate donor and virus protein as an acceptor. Consistent demonstration of the activity requires prior removal of phosphohydrolase. The kinase activity requires Mg(2+), is not stimulated by cyclic adenosine monophosphate, but is enhanced by added protamine or arginine-rich histone. The labeled product is resistant to ribonuclease, deoxyribonuclease, and chloroform-methanol but is sensitive to Pronase. Other tests suggest that serine and threonine residues are the acceptor sites. In the in vitro reaction, the incorporation represents an average of approximately 4,500 phosphate residues per virion, and all 17 virus protein bands resolved by polyacrylamide gel electrophoresis appear to be labeled.
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PMID:Protein kinase activity in equine herpesvirus. 433 15

Cell walls were isolated by mechanical disruption of mid-log phase cells of Bacillus stearothermophilus NCA 1503-4R grown in Trypticase-yeast extract-fructose medium at 55 C. The cell walls were purified by treatment with sodium dodecyl sulfate (SDS) and incubation with deoxyribonuclease and trypsin. The cell wall peptidoglycan contained glucosamine, muramic acid, alpha, epsilon-diaminopimelic acid, and glutamic acid. Low amounts of glycine, galactosamine, serine, aspartic acid, lysine, and valine were also present. The relative mole ratios of glutamic acid-alpha, epsilon-diaminopimelic acid-glycine-alanine were 1.00:1.26:0.08:1.55. The cell walls were free from ribonucleic acid and deoxyribonucleic acid and contained less than 0.2% chloroform-methanol extractable lipid and 0.09 mumole of phosphorus per mg of cell wall. Teichoic acid was not detected in the cell walls of this organism. Cell walls isolated without treatment with SDS contained 7.5% chloroform-methanol extractable lipid, 0.24 mumole of phosphorus per mg of cell wall, and relatively high concentrations of all amino acids. These results suggest that the extracted lipid is not a cell wall component per se, but a contaminant from the lipoprotein cell membrane.
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PMID:Chemical composition of the cell walls of Bacillus stearothermophilus. 603 16

Sixteen strains of Capnocytophaga were isolated from the pocket of a localized juvenile periodontitis patient. These strains were divided into four groups on the basis of morphological and physiological traits. Strains from group I and group III were identified as C. ochracea and group II as C. sputigena. An antigen common to genus Capnocytophaga was purified utilizing immunoabsorbent chromatography from lysates obtained by sodium dodecyl sulfate treatment of C. ochracea strain S1. An antigen specific to C. ochracea was prepared by sequential gel filtration and preparative isoelectric focusing. The genus common and species specific antigens isolated were immunologically unique and pure when tested by immunoelectrophoresis and immunodiffusion against rabbit antisera prepared to Capnocytophaga and other gram-negative rods. The genus common antigen was susceptible to trypsin and pronase digestion, was soluble in chloroform-methanol, but was unaltered by ribonuclease and deoxyribonuclease treatments and periodate oxidation. Antigenicity of the species specific antigen was destroyed by periodate oxidation. The genus common antigen appeared to be lipid-associated protein, while the species specific antigen consisted mainly of carbohydrate. These specific immunological reagents would be valuable in diagnosing and monitoring diseases.
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PMID:Isolation and partial characterization of a genus common antigen and species specific antigen of Capnocytophaga. 618 10

An extracellular bactericidal substance was isolated from the supernatant of Streptococcus mutans Rm-10 culture fluid and partially purified with 60% ammonium sulfate precipitation, differential centrifugation, and gel filtration on Sephadex G-200. There was a good correlation of the sensitivity profiles of indicator strains whether assayed on solid medium or with purified material from cell-free culture fluid, indicating that the same inhibitory substance is produced on solid medium and in broth. Vapor from organic solvents such as chloroform, acetone, ethanol, and ether as well as heat treatment at 100 degrees C for 30 min had little effect on the bactericidal factor. It was sensitive to trypsin and pronase and resistant to deoxyribonuclease, ribonuclease, lysozyme, and phospholipase C. The inhibitor was not infective, and electron microscopic studies failed to reveal phage or phage-like particles in concentrated solutions of the bactericidal material. The results indicate that the extracellular bactericidal substance is indeed a bacteriocin. Activity in broth cultures reached a maximum only after exponential growth had ceased. It was active against other streptococcal strains as well as strains of Actinomyces naeslundii, A. viscosus, Bacillus subtilis and Staphylococcus aureus, but not against strains of Fusobacterium nucleatum and Escherichia coli.
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PMID:Isolation, partial purification and preliminary characterization of a bacteriocin from Streptococcus mutans Rm-10. 641 23

The transfer of tetracycline resistance among strains of Clostridium difficile is described. Transfer occurred by a conjugation-like event that was insensitive to deoxyribonuclease, could not be mediated by donor culture filtrates or chloroform-treated donor cultures, and required cell-to-cell contact. Tetracycline-resistant progeny recovered from matings displayed a resistance phenotype identical to that of the donor in level of resistance, constitutive expression, and transmissibility. Although the original tetracycline-resistant donor contained 5 x 10(6)- and 22 x 10(6)-dalton plasmids, standard physical analyses of antibiotic-resistant transconjugants revealed no plasmid deoxyribonucleic acid molecules in common with the donor strain. Furthermore, tetracycline-susceptible derivatives of the original donor always possessed a plasmid complement identical to that of the resistant parental strain as determined by restriction endonuclease digestion analysis. The results indicate that the tetracycline resistance determinant(s) was not encoded by readily detectable plasmid deoxyribonucleic acid and may be chromosomally located.
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PMID:Transferable tetracycline resistance in Clostridium difficile. 727 Dec 79


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