Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The endotoxic activity of Fusobacterium necrophorum bov 5 was investigated. The supernatant (S) fluid and cell wall (CW) preparation, obtained after differential centrifugation of the ruptured cell mass, were lethal for mice. The toxicity of the S fluid was stable during prolonged storage, treatment with formalin, and heating for 15 minutes at 80, 100, and 121 C, but was destroyed by alkaline hydrolysis with 0.25 N NaOH. The toxic factor was found in a high molecular weight (MW) fraction after gel filtration. The properties exhibited by the toxic S fluid resembled those of endotoxic lipopolysaccharide (LPS). Extracted and partially purified LPS (endotoxin) from F necrophorum bov 5 demonstrated a mouse median lethal dose (mouse LD50) of 16.8 mg/kg of body weight. The toxic LPS material, a high molecular weight moiety as estimated by gel filtration, was resistant to ribonuclease (RNase), deoxyribonuclease (DNase), and pronase treatment. A positive Shwartzman reaction (median skin lesion dose (SLD50) equal to 3.32 mug/kg of body weight) and biphasic fever response (minimal dose required to produce a fever index of 40 sq cm which falls on the linear portion of dose-response curve (FL40) equal to 0.41 mug/kg of body weight) further indicated the toxin was endotoxin in nature. The LPS from F necrophorum bov 5 was less toxic than Salmonella typhimurium LPS; but had considerable toxicity for experimental animals. The toxic activity of the partially purified F necrophorum bov 5 endotoxin was separated into 2 fraction regions by diethylaminoethyl (DEAE)-cellulose chromatography. The data provide evidence for the production of a potent endotoxin, possibly composed of more than one toxic component, which may be released upon cell disruption.
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PMID:Endotoxin from Fusobacterium necrophorum of bovine hepatic abscess origin. 114 41

To investigate the possibility that mitochondrial transcription could be altered in tumours we started by characterizing the RNA obtained from mitochondria, isolated from Walker carcinosarcoma and purified by a procedure devised to compensate for the lower size and density of these organelles in 10-day tumours. The RNA was extracted by the 'hot phenol' technique and analysed by electrophoresis in 2.7 and 2.5% polyacrylamide gels at different running times, identifying the usual cytoplasmic contaminants 28 and 18S peaks plus the other five major peaks at 40, 20.5, 16.3, 15.4, and 4Se. The 28 and 18Se peaks were not eliminated by digitonin treatment of the mitochondria, indicating that they arise from cytoplasmic ribosomes tightly associated with the mitochondria. From its sensitivity to DNAase (deoxyribonuclease), resistance to RNAase (ribonuclease) and coincidence with external marker DNA, the 40Se peak was identified as containing mainly DNA. Sucrosegradient centrifugation for different periods showed a major component at 16.2S, the 28 and 18S cytoplasmic RNA species, peaks at 13.8, 6.4 and 4S and a small 19.5S peak. By polyacrylamide-gel electrophoresis of the purified RNA classes separated by one or two cycles of centrifugation, the following correlation were established: 20.5Se19.5S; 16.3Se16.2S; 15.4Se13.8S. The 6.4S RNA ran as a mixture of 4 and 4.7Se species. When the 20.5Se and 15.4Se RNA species were centrifuged, they behaved as 16.2S and 13.8S respectively, thus suggesting that the 16.2S (16.3Se) arises by cleavage from the 19.5S(20.5Se), the 13.8S (15.4Se) being the other RNA from mitochondrial ribosomes.
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PMID:Electrophoretic and centrifugation behaviour of mitochondrial ribonucleic acid from Walker 256 carcinosarcoma. 115 77

Strains from type culture collections and clinical isolates belonging to the Aeromonas and Pseudomonas genera were identified with conventional tests. Production of extra-cellular enzymes and haemolysins were detected by simple plate agar methods. The following enzymes were found to be of special value for a rapid and simple classification of certain species in both genera: potease (casein and gelatin agar), lecithinase (lecithin agar), and deoxyribonuclease (DNA agar). Elastase, staphylolytic enzyme, lipase, ribonuclease, amylase, and egg yolk reaction were other enzymes studied. However, these tests were not positive for more than 90% of any species. A. hydrophila, A. salmonicida, and P. aeruginosa were haemolytic on agar containing rabbit erythrocytes.
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PMID:Characterization of three Aeromonas and nine pseudomonas species by extracellular enzymes and haemolysins. 117 Apr 82

We have investigated the ability of dehydroepiandrosterone (DHEA) to alter the production of interleukin-2 (IL-2) and to bind to a specific binding complex in antiCD3 epsilon activated T cells. Binding activity correlated with the presence of a specific DHEA binding complex in the cytosol and nuclei of DHEA-responsive T-cell hybridomas, as well as in CD4+ and CD8+ cells isolated from peripheral lymph nodes of normal mice. Scatchard analysis determined that intact lymphocytes and cytosolic fractions contained high affinity binding for [3H]DHEA (approx. 2.6 nM) with 1000-7000 binding sites existing per cell. Five of the T-cell hybridomas tested both responded to DHEA treatment with increased production of IL-2 and also contained specific high affinity [3H]DHEA binding. Four additional T-cell hybridomas were found to contain no specific [3H]DHEA binding and were also unresponsive to DHEA influences on IL-2 production. Sucrose density gradients demonstrated a 3-4s [3H]DHEA binding complex in high salt and a 7-8s binding complex in low salt. Specific binding was inhibited by preincubation of the cytosol fractions with either trypsin or chymotrypsin, or by heating to 60 degrees C for 1 h (less than 15% of control). [3H]DHEA binding was unaffected by preincubation of the cytosol fractions with ribonuclease, deoxyribonuclease, or phospholipase A. The DHEA-protein complexes bound to DNA-cellulose with the amount of binding being slightly increased by preincubation at 25 degrees C as compared to 4 degrees C. As expected, [3H]DHEA binding was inhibited by the addition of unlabeled DHEA, but was also modestly inhibited by dihydrotestosterone and cortisol. Binding of DHEA was unaffected by progesterone, dexamethasone, estradiol, androsterone, DHEAS, and beta-etiocholanolone at all concentrations tested. DHEA was incapable of inhibiting the binding of [3H]DHT to the androgen receptor or [3H]dexamethasone to the glucocorticoid receptor. Collectively, these findings suggest that murine T cells contain a specific DHEA receptor. We believe that DHEA is a steroid hormone that is directly involved in the regulation of IL-2 production by both normal and some T-cell hybridomas.
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PMID:The presence of a dehydroepiandrosterone-specific receptor binding complex in murine T cells. 135 1

For simultaneous cytophotometric measurement of DNA and RNA, the standardized Methyl Green-Pyronin Y technique is an obvious choice. It is, however, first necessary to correlate the uptake of Pyronin Y to the staining intensity of RNA. The material consisted of paraffin sections of formalin- or Carnoy-fixed rat liver. The sections were pretreated with water, buffer, deoxyribonuclease, ribonuclease, or both enzymes in sequence, and stained with the standardized Methyl Green-Pyronin Y procedure, Gallocyanin chromalum, or the Feulgen reaction. Sections stained directly without pretreatment served as controls. Staining intensities were measured with an image analyser for cell nuclei, nucleoli and cytoplasm. After deoxyribonuclease treatment, nuclear staining intensity with Methyl Green, Gallocyanin chromalum, and Schiff's reagent dropped nearly to zero. The same was seen for both nucleoli and cytoplasm with Pyronin Y and Gallocyanin chromalum after ribonuclease treatment. Staining intensity of Pyronin Y correlated directly with that of Gallocyanin chromalum for nucleoli and cytoplasm. After ribonuclease treatment, a direct correlation was found between the nuclear staining intensity of Methyl Green and nuclear absorption of Gallocyanin chromalum. We conclude that the standardized Methyl Green-Pyronin Y stain is reliable for the simultaneous quantitative assessment of both RNA and DNA. The simplicity of this technique makes it a valuable tool even for daily routine.
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PMID:Simultaneous quantification of DNA and RNA in tissue sections. A comparative analysis of the methyl green-pyronin technique with the gallocyanin chromalum and Feulgen procedures using image cytometry. 137 24

It is generally assumed that the machinery that transcribes genes is composed entirely of polypeptides. However, in vitro transcription by silkworm RNA polymerase III requires a transcription factor that is not a polypeptide. This component, TFIIIR, is distinct from the previously identified transcription components: RNA polymerase III, and the accessory factors TFIIIA, TFIIIB, TFIIIC, and TFIIID. The newly discovered TFIIIR is a macromolecule that appears to be composed of RNA. It is resistant to heat, detergent, phenol, protease, and deoxyribonuclease, but it is sensitive to alkali and ribonuclease.
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PMID:A class III transcription factor composed of RNA. 170 25

Mediators released from injured human skin that initiate the inflammatory response have not been adequately identified. Organ culture of full-thickness skin explants enables us to do so, because injury to the skin can be made in vitro, eliminating the rapid leakage of serum and infiltration of leukocytes that occur in vivo. In our studies, the military vesicant sulfur mustard (SM) (10 microliters of a 0.01 to 1.0% dilution) was topically applied to injure the epidermis of the explant. Then, the explants were cultured in small Petri dishes, usually for 18 h at 36 degrees C, and the organ-culture fluids were assayed for various inflammatory mediators. We found that the culture fluids from SM-exposed and control explants contained similar amounts of angiotensin-converting enzyme, trypsin-like and chymotrypsin-like proteases, acid phosphatase, beta-glucuronidase, beta-galactosidase, lysozyme, deoxyribonuclease, ribonuclease, interleukin 1, and lactic dehydrogenase. However, the culture fluids from SM-exposed explants contained increased amounts of histamine and plasminogen-activating activity, and often prostaglandin E2, when compared to culture fluids from control explants. After 3 to 4 d in culture, full-thickness human skin explants, when exposed to 0.2% SM (but not when exposed to 1.0% SM), sometimes showed separation of the epidermis and increased collagenase activity (i.e., hydroxyproline release). Thus, histamine (from local mast cells), and prostaglandin E2 and plasminogen-activating activity (probably from both mast cells and epidermal cells) are apparently involved in early mediation of the inflammatory response.
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PMID:Mediators, initiating the inflammatory response, released in organ culture by full-thickness human skin explants exposed to the irritant, sulfur mustard. 171 Jun 39

Synthetic chocolate colourant, flavourant and the mixture of both were administered to healthy adult male albino rats to evaluate their effect on the nucleic acids metabolism, i.e. deoxyribonucleic and ribonucleic acids (DNA and RNA), total serum protein, thyroid hormones (T4 and T3) and nuclease enzymes, i.e. cytoplasmic- and mitochondrial deoxyribonuclease and ribonuclease (DNase and RNase) in brain, liver, and kidneys. Also, the activity of the fundamental enzymes of the oxidative pentose phosphate pathway, i.e. cytoplasmic and mitochondrial glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase (G-6-PD and 6-PGD), as well as total lipids and cholesterol contents in the same organs were studied. Ingestion of the studied food additives significantly increased serum protein, RNA and T4 hormone, while, DNA and T3 hormone were insignificantly elevated. In connection with this, the hydrolytic enzymes of nucleic acids (DNase and RNase activities) were stimulated by all studied food additives and in all mentioned organs. The activity of G-6-PD and 6-PGD in both cytoplasmic and mitochondrial fractions of all studied organs were increased. The highest increase was noticed in rats fed on diets supplemented with the mixture of both colourant and flavourant followed by colourant then flavourant, respectively.
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PMID:Biochemical effect of chocolate colouring and flavouring like substances on thyroid function and protein biosynthesis. 171 48

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

Autoantibody reactive with tRNA was identified by immunoprecipitation of Hela cell extract. Four out of 56 sera from patients with autoimmune chronic active hepatitis (CAH), and four out of 35 sera from patients with primary biliary cirrhosis (PBC) contained antibody directed against gel-purified tRNA in Hela cell extract, but no sera obtained from CAH type B, CAH non-A, non-B, or healthy volunteers did. Further studies on these eight anti-tRNA sera disclosed that 6 of the 8 sera that immunoprecipitated tRNA from Hela cell extract, reacted with purified tRNA, but reacted with neither 5sRNA nor ribosomal RNA species. After proteinase and deoxyribonuclease digestion of Hela cell extract, the epitope for these 6 sera was conserved, and the antigen was sensitive to ribonuclease (anti-tRNA serum). Purified Hela cell DNA digested with Eco RI or Hind III (denatured or non-denatured) could not be immunoprecipitated by these sera. In a patient with autoimmune CAH, the anti-tRNA antibody was weakly positive at week 2 and disappeared 2 months after steroid therapy started, "in parallel" with disappearance of anti-nuclear antibody. In the other 2 sera, the antigen was sensitive to proteinase.
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PMID:Autoantibody specific for transfer ribonucleic acid (tRNA) in patients with autoimmune chronic active hepatitis and primary biliary cirrhosis. 177 87


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