Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

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

Very fast-sedimenting DNA was isolated from cells after infection with gene 49 defective phage T4. This DNA appeared membrane bound throughout the time after infection and could be isolated either in the membrane-bound form (M-DNA) or free of membrane (released DNA) depending on the lysis procedure. Released DNA formed complexes of marked stability with sedimentation velocities between 1,400S and 2,100S. These complexes did not seem to contain material other than DNA. This was concluded from the results of RNA, protein, and membrane labeling experiments and density analysis. In addition, these complexes were resistant against treatment with n-butanol, phenol. chloroform-methanol, sodium dodecyl sulfate, Sarkosyl, Pronase, RNase, or lysozyme. The observation that more then 90% of the purified very fast-sedimenting DNA is retrapped by magnesium-Sarkosyl crystals (M-band) suggests that the M-band technique may not be sufficient as a test for DNA-membrane attachment.
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PMID:Function of gene 49 of bacteriophage T4. I. Isolation and biochemical characterization of very fast-sedimenting DNA. 77 32

A strain of Actinomyces odontolyticus, originally isolated from human dental plaque, produced a non-dialyzable, trypsin-sensitive substance that was bactericidal for certain strains of bifidobacteria at 42 degrees C but not at 37 degrees C. Detectable quantities of the bacteriocin were not produced in liquid media. Experimentally useful yields were obtained by extraction from pour plate cultures of producer cells. At 42 degrees C, exponential killing did not occur until indicator cells had doubled at least once. At 37 degrees C, the bacteriocin effected a transient bacteriostasis. Partially purified concentrates were obtained by diethylaminoethyl-cellulose chromatography, and such material was not inactivated by ribonuclease, deoxyribonuclease, or lipase. Pronase, trypsin, and exposure to 100 degrees C for 20 min completely abolished activity. Inhibitory activity was considerably reduced by exposure to a pH of either 3 or 11. Treatment of producer cells with curing agents did not induce a high frequency of non-bacteriocinogenic cells. The odontolyticin was adsorbed by susceptible, as well as resistant, bacteria.
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PMID:Bacteriocin from Actinomyces odontolyticus with temperature-dependent killing properties. 90 31

An inhibitor of ribonucleic acid polymerases has been obtained from the mycelial phase of Histoplasma capsulatum and partially characterized. The inhibitor, called histin, was purified 200-fold by heat treatment at 100 C and electrophoresis on polyacrylamide gels. Histin moved in electrophoresis as if negatively charged; it was insensitive to treatment with ribonuclease of deoxyribonuclease but was completely digested by Pronase. Sucrose gradient centrifugation suggests a molecular weight of 24,000. The possibility of a regulatory role for histin in the life cycle of H. capsulatum is discussed.
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PMID:Characterization of an inhibitor of ribonucleic acid polymerase from the mycelial phase of Histoplasma capsulatum. 112 17

Human lymphocytes were shown to release, in vitro and in the absence of any stimulation, a complex containing DNA. It has also been reported that the release process is unrelated to cell death and is regulated by a homeostatic mechanism. Some properties of the extracellular DNA were investigated. When a phosphorylated precursor was added to the cell-free supernatant, the DNA recovered from the medium was labeled. Evidence that DNA lebeling represented true precursor incorporation and not simple attachment was obtained from nearest neighbor analysis data. When [alpha-32P]thymidine triphosphate was added to the supernatant and the labeled DNA was completely hydrolyzed to 3'-deoxyribonucleotides, radioactivity was found in all four nucleotides. Although the exact kind of synthesis cannot be determined at this stage, the possibility of a terminal transferase system in which the enzyme would merely add a nucleotide at the end of the chain was eliminated since comparative digestion with DNase and venom phosphodiesterase showed that labeling was located along the whole length of the chain. Precursor incorporation into the DNA was inhibited by DNase, RNase, Pronase, and actinomycin D. This extracellular synthesis was not affected by cell death rate. The renaturation curve of the extracellular [3H]DNA synthesized in the cell-free medium showed a lack of gene reiteration suggesting a preferential synthesis of unique sequences.
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PMID:Spontaneous extracellular synthesis of DNA released by human blood lymphocytes. 127 93

It was found, in cell-free assays, that the Man8GlcNAc2 and Man7GlcNAc2 isomers having the mannose unit to which the glucose is added were glucosylated by the rat liver glucosyltransferase at 50 and 15%, respectively, of the rate of Man9GlcNAc2 glucosylation. This indicates that processing by endoplasmic reticulum mannosidases decreases the extent of glycoprotein glucosylation. All five different glycoproteins tested (bovine and porcine thyroglobulins, phytohemagglutinin, soybean agglutinin, and bovine pancreas ribonuclease B) were found to be poorly glucosylated or not glucosylated unless they were subjected to treatments that modified their native conformations. The effect of denaturation was not to expose the oligosaccharides but to make protein determinants, required for enzymatic activity, accessible to the glucosyltransferase because (a) cleavage of denatured glycoproteins by unspecific (Pronase) or specific (trypsin) proteases abolished their glucose acceptor capacities almost completely except when the tryptic peptides were held together by disulfide bonds and (b) high mannose oligosaccharides in native glycoproteins, although poorly glucosylated or not glucosylated, were accessible to macromolecular probes as concanavalin A-Sepharose, endo-beta-N-acetylglucosaminidase H, and jack bean alpha-mannosidase. In addition, denatured, endo-beta-N-acetylglucosaminidase H deglycosylated glycoproteins were found to be potent inhibitors of the glucosylation of denatured glycoproteins. It is suggested that in vivo only unfolded, partially folded, and malfolded glycoproteins are glucosylated and that glucosylation stops upon adoption of the correct conformation, a process that hides the protein determinants (possibly hydrophobic amino acids) from the glucosyltransferase.
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PMID:Recognition of the oligosaccharide and protein moieties of glycoproteins by the UDP-Glc:glycoprotein glucosyltransferase. 153 Oct 24

Our previous studies have demonstrated the production and release of a tumor-derived factor that promoted lipolysis in normal adipocytes. We further demonstrated that this in vitro lipolysis was correlated with the in vivo loss of total carcass lipids induced by the presence of the same tumor. This study identified and isolated this "lipolysis-promoting" factor (LPF), released into the extracellular environment (conditioned media) by the human A375 melanoma cell line, which appears to be responsible for the previously demonstrated induction of in vitro and in vivo lipolytic activity. Unlike previously described non-tumor-derived molecules, such as tumor necrosis factor-alpha/cachectin, which have been implicated in cancer cachexia, the LPF induces alterations in lipid metabolism similar to those observed in cancer patients. The biochemical nature of human tumor-derived LPF appears to be a heat-stable molecule with an apparent molecular weight of approximately 6000. The lipolysis-promoting activity was trichloroacetic acid precipitable, but not precipitable with protamine sulfate or extractable with chloroform:methanol. Its activity appears to be resistant to enzymatic treatments with protease K, trypsin, Pronase, RNase, and DNase, as well as to periodate oxidation. Immunochemically, LPF appears to be distinct from tumor necrosis factor-alpha/cachectin. Furthermore, in contrast to the mechanism of action of tumor necrosis factor-alpha/cachectin, the mechanism of "lipolysis promotion" by LPF appears to be by the induction of cellular lipase activity.
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PMID:Identification of a human tumor-derived lipolysis-promoting factor. 173 44

Nucleolar organizer region (NOR) silver staining was applied to sections of fixed material. A positive reaction on cryo-ultrathin sections was found as well as on semithin and ultrathin Lowicryl sections. Repeatable staining that was easy to control was obtained by a one-step procedure after aldehyde-Carnoy fixation. Fixation of the material by formaldehyde and glutaraldehyde alone in cacodylate buffer also maintained reaction selectivity when ammonium chloride was used after fixation. Enzymatic digestion by pronase, RNase A, DNase I, or micrococcal nuclease was applied to ultrathin Lowicryl sections. Pronase digestion removed the silver-stained proteins, whereas digestion by the nucleases did not. A routine procedure is proposed for easy NOR silver staining of sections that preserves a good tissue ultrastructure and is also compatible with cytochemical and immunological investigations.
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PMID:Silver staining of the nucleolar organizer regions (NORs) on Lowicryl and cryo-ultrathin sections. 258 Aug 79

A convenient method for the determination of unfolding rates of small globular proteins under physiological conditions was developed using digestion with proteases. The apparent first-order rate constants for digestion of lysozyme with thermolysin and with Pronase at pH 8 and 50 degrees C were shown to be saturated with increases of concentrations of these proteases. The maximum rate constants extrapolated were identical in digestions with two different proteases, and were found to be equal to the unfolding rate constant of lysozyme. Similarly, the unfolding rate constant of RNase A at pH 8 and 50 degrees C, and those of lysozyme, RNase A and beta-lactoglobulin at pH 8 and 40 degrees C, were determined by the digestion method. Thus, it was shown that digestion by proteases proceeds mainly via the unfolded state of proteins.
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PMID:Unfolding rates of globular proteins determined by kinetics of proteolysis. 378 15


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