Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By following careful procedures, mycobacterial ribosomal fractions and ribonucleic acid (RNA) prepared by ethyl alcohol precipitation were obtained which have immunogenic activities similar to the viable attenuated H37Ra cells of Mycobacterium tuberculosis from which they were obtained. This comparison was based on the amount of ribonucleic acid (RNA) present. These preparations consisted of approximately 63% RNA and 37% protein; no deoxyribonucleic acid or polysaccharide was detected by chemical tests. A high correlation was found between the immunogenic activity of a preparation and the per cent increase in hyperchromicity at 260 nm of a ribonuclease-hydrolyzed portion. Final concentrations of sodium dodecyl sulfate higher than 0.25% when used for the preparation of the ribosomal fractions and RNA resulted in significantly lower immune responses and greater variation between experiments. This was not related to the amount of protein present. The stability of the ribosomal and RNA preparations was tested under a variety of conditions. The need for a good protective adjuvant again was shown since mouse serum readily hydrolyzed the RNA. Equal immunity was obtained after immunization by the intraperitoneal and subcutaneous routes; however, no immune response was obtained when the intravenous route was used. Preliminary results with RNA prepared with phenol showed that it was more easily degraded during preparation. This resulted in a lower immune response than was obtained with the RNA prepared with ethyl alcohol.
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PMID:Factors affecting immunogenic activity of mycobacterial ribosomal and ribonucleic acid preparations. 497 47

1. Highly purified mitochondria containing 3.0mug of RNA/mg of mitochondrial protein were prepared from rat liver by differential centrifugation. 2. RNA, labelled with [(32)P]P(i) or [(3)H]orotate, was isolated from these mitochondria by a phenol extraction method. The RNA sedimented at 15S and 13S on sucrose density gradients. Its nucleotide composition was 23% uridylate, 30% adenylate, 22% guanylate and 25% cytidylate. 3. RNA from mouse L cells was labelled with [(3)H]-uridine in the presence of 0.1mug of actinomycin D/ml to suppress the synthesis of cytoplasmic rRNA. The RNA isolated from crude L-cell mitochondria by a cold-phenol-sodium dodecyl sulphate method had components sedimenting at 15S and 12.5S. These components had an electrophoretic mobility on agarose-acrylamide gels of 21 and 12S(E) compared with 28 and 18S(E) for cytoplasmic rRNA. The nucleotide composition was 26% uridylate, 34% adenylate, 18% guanylate and 22% cytidylate. 4. RNA extracted from crude L-cell mitochondria by a hotphenol-sodium dodecyl sulphate method had an additional component sedimenting at 21S and having an electrophoretic mobility of 18S(E). It was probably DNA because of its sensitivity to deoxyribonuclease and its insensitivity to ribonuclease and alkali. It was present in nuclear fragments contaminating the crude mitochondrial fraction and could be removed by deoxyribonuclease or isopycnic-gradient centrifugation.
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PMID:Ribosomal-type ribonucleic acid from rodent mitochondria. 549 58

The synthesis of vaccinia virus double-stranded ribonucleic acid (RNA) in infected HeLa cells was sensitive to actinomycin D, suggesting that a deoxyribonucleic acid dependent reaction is involved. Some double-stranded RNA was made in the presence of cytosine arabinoside in infected cells. Double-stranded and complementary RNA were synthesized in vitro by using vaccinia cores. These two observations indicate that some of the double-stranded RNA is read from "early" genes. The double-stranded RNA synthesized in vitro had the same properties as that made in vivo. At least 70% of the double-stranded RNA made in vivo was in ribonuclease-resistant form prior to sodium dodecyl sulfate-phenol extraction. In addition, there was a complementary RNA in infected cells which could be converted to double-stranded RNA by annealing.
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PMID:Mechanism of synthesis of vaccinia virus double-stranded ribonucleic acid in vivo and in vitro. 554 34

Infectious ribonucleic acids (IRNA) of Venezuelan equine encephalitis and Eastern equine encephalitis viruses were observed to form noninfectious complexes with a basic polyamino acid, poly-l-lysine. Original infectivity was recovered from the complexes by digestion of the polylysine with Pronase, and partial recovery was effected by treatment with sodium dodecyl sulfate. Infectivity could not be recovered from the complexes containing polylysine of 100,000 molecular weight by changes in ionic strength, pH, or by treatment with phenol, deoxycholate, or digitonin. Masking of infectivity by polylysine was demonstrated in vivo as well as by plaque assay in tissue culture. Poly-l-lysine preparations of high molecular weight (44,000 to 100,000) were more effective than low molecular weight (3,000) materials in masking infectivity of IRNA. When complexes, in which infectivity had been masked by low molecular weight polylysine, were suspended in 1 m NaCl, some infectivity was recovered. Complexes of polylysine-IRNA differed from control IRNA alone in (i) resistance to inactivation by ribonuclease, (ii) sedimentation patterns in sucrose gradient centrifugation, and (iii) stability of recoverable infectivity during different physical treatments.
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PMID:Effects of poly-L-lysine on infectious viral nucleic acid. 555 81

Infection of baby hamster kidney cells (BHK-21/13) with Saint Louis encephalitis (SLE) virus depressed the rate of protein and ribonucleic acid (RNA) synthesis until viral RNA synthesis began 6 hr postinfection (PI). Virus-directed RNA synthesis was subsequently inhibited until 12 hr PI when virion maturation began. The rate of protein synthesis reached a peak 6 hr PI and was subsequently depressed until just before the onset of virion maturation. Density gradient analysis of phenol-extracted RNA from actinomycin-treated infected cells indicated that, at 6 to 8 hr and again at 12 to 20 hr PI, three species of viral-specific RNA were synthesized. The most rapid sedimenting form (43S) was ribonuclease-sensitive and had a base composition similar to the RNA isolated from mature virions. The 20S RNA species was ribonuclease-resistant and had a sedimentation coefficient and base composition similar to the replicative form associated with other arbovirus infections. The 26S RNA was ribonuclease-resistant (0.2 mug/ml, 0.1 m NaCl, 25 C, 30 min) and had a nucleotide base composition closer to the 20S form than to the values for 43S RNA. Five-minute pulse labeling of infected cultures during the period viral RNA synthesis was maximal resulted in labeling of only the 20S to 22S RNA fractions. With pulse-labeling periods of 10 min, both the 20S and 26S RNA species were radioactive. Periods of radioactive labeling of as long as 15 min were required before the 43S form was radioactively labeled. These results suggest that the 20S and 26S RNA may be intermediate forms in the synthesis of 43S viral RNA.
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PMID:Synthesis of Saint Louis encephalitis virus ribonucleic acid in BHK-21-13 cells. 577 65

When indoleacetic acid labeled with carbon-14 in the carboxyl group is fed to excised green pea-stem segments, growth is initiated, and there is a parallel progressive labeling of the RNA extracted by cold phenol. The bulk of the label is found in the 4S fraction. This fraction is more resistant to degradation by ribonuclease than a similar fractian obtained from tissue not treated with indoleacetic acid.
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PMID:Hormone-induced stabilization of soluble RNA in pea-stem tissue. 583 39

Infectious entities, extractable, with phosphate buffer, from tissue infected with potato spindle tuber virus and inciting symptoms on tomato that are typical of this virus, have properties incompatible with those of conventional virus particles. The infectious particles sediment in sucrose density gradients at approximately the same rate as particles with a sedimentation coefficient of 10S, are insensitive to treatment with organic solvents, and can be concentrated by ethanol precipitation. Treatment with phenol changes neither their infectivity nor their sedimentation properties. Infectivity is insensitive to deoxyribonuclease, but at low ionic strength it is sensitive to ribonuclease. At high ionic strength, infectivity partially survives incubation with ribonuclease. These properties, as well as elution patterns from columns of methylated serum albumin, suggest that the extractable infectious agent may be a double-stranded RNA.
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PMID:Potato spindle tuber virus: a plant virus with properties of a free nucleic acid. 606 89

The supernatant fluids of batch and continuous cultures of Brucella strains contained up to 100 mg/l of soluble RNA which could be recovered by precipitation with lysozyme, This RNA fraction had many of the properties of ribosomal RNA and was single-stranded, sensitive to ribonuclease, with an approximate sedimentation constant of 5S, a molecular weight of about 35000 daltons and an adenine; guanine; cytosine; uracil content of 17.5; 26.5; 33; 23 mol% respectively. RNA fractions from lysozyme precipitates evoked high titres of Brucella agglutinins on injection into rabbits and induced acute inflammatory responses in guinea-pig skin. Highly purified RNA fractions prepared by phenol extraction of lysozyme precipitates did not evoke antibodies to Brucella abortus.
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PMID:Isolation and properties of an RNA fraction present in Brucella culture supernatants. 615 68

A cell suspension derived from a single murine spontaneous mammary adenocarcinoma was resolved on a linear gradient of Ficoll, into twelve distinct neoplastic cell subpopulation. A second cell suspension, also derived from a single murine mammary adenocarcinoma was first treated with vibrio cholera neuraminidase (VCN) then was resolved on an identical gradient of Ficoll into twelve distinct subpopulation. Each cell population was seeded and allowed to proliferate. The cell subpopulations differed in their doubling time, cloning efficiency, tumorigenicity and metastatic capacity. Although in vivo the murine spontaneous mammary adenocarcinoma (SMMAdCa) never metastasized, SMMAdCa-10 subpopulation metastasized into lymph nodes and lungs. All VCN-modified subpopulations were non-oncogenic. Cells from each population were used to immunize groups of syngeneic mice. The spleens of each group were pooled and Immune-RNA's were extracted with the phenol-water standard technique. The IRNA's preparations stimulated DNA synthesis in normal murine spleenocytes. The various I-RNA's differed in their biological activities, base composition and their sensitivity to ribonuclease.
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PMID:Enzymically-mediated changes in murine mammary adenocarcinoma cell membrane induces changes in lymphoid tissue immune ribonucleic acids. 616 33

Ribonucleoprotein particles were isolated from unfertilized eggs and gastrula stages of Xenopus laevis. The particles from both stages induce in gastrula ectoderm the formation of large foreheads (neural-archencephalic-inducing activity), whereas ribosomal subunits have no inducing activity. The inducing activity of particles from both stages is largely abolished after treatment with proteolytic enzymes and to some extent with ribonuclease. The protein moiety of gastrula ribonucleoprotein particles was extracted with phenol and the protein reduced with 2-mercaptoethanol. The protein induces foreheads, but at a lower rate than the intact particles. The protein was fractionated by high-performance liquid size-exclusion chromatography on a derivatized silica gel with 75% formic acid as eluent. The fraction which includes proteins from 10 000 to 16 000 Da has the highest neural-archencephalic-inducing activity.
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PMID:Ribonucleoprotein particles from Xenopus eggs and embryos. Neural-archencephalic-inducing activity of the protein moiety. 637 Jun 94


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