Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The effects of both 3,5,3'-triiodo-L-thyronine and spontaneous metamorphosis on Rana catesbeiana liver mRNA were studied using in vitro translation of isolated liver poly(A)+ RNA in a rabbit reticulocyte lysate system. Conventional phenol extraction methods yielded degraded RNA due to high levels of endogenous ribonucleases released upon homogenization of Rana catesbeiana liver. Isolation of intact total RNA was achieved using the potent ribonuclease denaturant, guanidinium thiocyanate. Adult bullfrog serum albumin was purified to homogeneity and a monospecific antibody was elicited against it. A serum protein of 23,000 daltons that migrated near serum albumin on a 6% native gel was also purified to homogeneity. A monospecific antibody was also raised against this protein. Both antibodies were used to quantitatively immunoprecipitate the in vitro translation products of poly(A)+ RNA isolated at intervals following a single injection of triiodothyronine or during various stages of spontaneous amphibian metamorphosis. Triiodothyronine caused a sevenfold increase in translatable albumin mRNA and a threefold increase in translatable mRNA for the 23,000 dalton protein. These increases are consistent with a nuclear initiated mechanism for thyroid hormone action during amphibian metamorphosis.
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PMID:Triiodothyronine increases translatable albumin messenger RNA in Rana catesbeiana tadpole liver. 314 56

A new approach has been developed to circumvent the problems of false positive reactions in the Limulus Amoebocyte Lysate (LAL) assay for lipopolysaccharide (LPS) in root surface materials. These LAL-reactive materials include thrombin, thromboplastin, ribonuclease, ribonucleic acid, lipoteichoic acid and peptidoglycan fragments. In the present study, hot phenol/water extraction of these substances followed by ultracentrifugation of the resulting aqueous phases reduced their concentrations to very low levels. Furthermore, the application of Polymyxin B/Sepharose 4B affinity chromatography to these extracts enabled their intrinsic LAL-activity to be determined. Use of these techniques to assay root surface materials has identified LPS as being the major LAL-reactive material present. The mean LPS yield for the periodontally involved teeth was 4.13 micrograms/tooth, representing 2.82 micrograms/root. In contrast, the mean yield of LPS for the periodontally uninvolved teeth was 3.12 ng/tooth.
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PMID:Identity of limulus amoebocyte lysate-active root surface materials from periodontally involved teeth. 346 18

Phenol has been added to the Coomassie Brilliant Blue G-250 dye reagent used in the standard Bradford protein assay and its effect upon the reagent blank and assay response of fourteen proteins investigated. Phenol can enhance or impair colour yield depending upon its concentration and the amount and type of protein assayed. Four characteristic protein responses to increasing assay concentrations of phenol have been observed. These indicate a complex influence of phenol upon the protein assay. Dye reagent containing 0.5% phenol gave optimal colour yield with most of the proteins investigated and an improved assay response of ovalbumin, ribonuclease, lysozyme, insulin, pepsin and chymotrypsinogen-A relative to bovine albumin.
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PMID:Phenol addition to the Bradford dye binding assay improves sensitivity and gives a characteristic response with different proteins. 378 18

A lipopolysaccharide (LPS) fraction was extracted from Nichols, nonpathogenic Treponema pallidum by the hot, phenol-water procedure. The LPS was freed of nucleic acids and water-soluble proteins by successive exposures to ribonuclease, deoxyribonuclease, and Pronase. Purified LPS responded positively in a colorimetric assay for lipopolysaccharide. Electron microscope examination of the LPS both before and after purification demonstrated a heterogeneous mixture of forms including spheres, doughnuts, and ribbons. The trilaminar nature of the ribbon forms was observed by both negative staining and thin sectioning. Lyophilization of the LPS caused an increase in the number and length of ribbon forms seen. Results suggest that the surface layers of treponemes are similar to those of gram-negative bacteria.
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PMID:Ultrastructure of lipopolysaccharide isolated from Treponema pallidum. 412 67

1. Treatment of washed rat liver microsomes in a medium containing 0.12m-sucrose, 12.5mm-potassium chloride, 2.5mm-magnesium chloride and 25mm-tris-hydrochloric acid buffer, pH7.6, with 2m-lithium chloride at 5 degrees for 16hr. leads to the formation of membranes free of ribosomes and ribosomal subunits. 2. Confirmation of the absence of ribosomes from lithium chloride-prepared membranes was obtained by treatment of the membranes with sodium deoxycholate, followed by sucrose-density-gradient centrifugation, which showed the complete absence of ribosomes. 3. Treatment of membranes with phenol, followed by sucrose-density-gradient analysis of the isolated RNA, showed the presence of a small amount of 4s material. Repetition of the phenol extraction procedure in the presence of liver cell sap as a ribonuclease inhibitor again showed the presence of only 4s material. The 4s RNA was shown to be transfer RNA by the fact that it had the same capacity for accepting (14)C-labelled amino acids as isolated transfer RNA from rat liver pH5 enzyme. 4. Analysis showed that microsomes and membranes possessed similar glucose 6-phosphatase, NADH-2,6-dichlorophenol-indophenol reductase, NADH-neo-tetrazolium reductase, NADH-cytochrome c reductase and ribonuclease activities. 5. (3)H-labelled ribosomal RNA binds to membranes. However, isolation of the bound RNA by the phenol extraction procedure, followed by sucrose-density-gradient analysis, shows the RNA to be degraded to 7s material. Very little breakdown of (3)H-labelled ribosomal RNA bound to membranes occurs if the binding and isolation are carried out in the presence of liver cell sap.
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PMID:Preparation of ribosome-free membranes from rat liver microsomes by means of lithium chloride. 431 14

Mouse mammary tumor virus (MTV) was isolated from the milk of RIII mice by density-gradient centrifugation in Ficoll. The homogeneity of the preparation was demonstrated in electron micrographs. The nucleic acid was extracted with phenol in the presence of Pronase. Its viral origin was attested by failure of ribo-nuclease and deoxyribonuclease treatment of the virus preparation to destroy the filamentous molecules; after phenol extraction, the molecules were destroyed by ribonuclease but not by deoxyribonuclease. Rotary shadowed preparations were examined in the electron microscope. The length distribution of the RNA filaments showed peaks at 1.2, 2.4, and 3.6 mum. The molecular weight of the longest molecule of MTV-RNA was estimated as 3.6 x 10(6) daltons.
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PMID:Electron microscopy of the nucleic acid of mouse mammary tumor virus. 431 50

Treatment of insect polyribosomes with 1 M KCl released a messenger ribonucleoprotein with a pronounced 16S peak. Phenol extraction resulted in a defined peak of 10S RNA, which was judged as mRNA by the following criteria: it showed specificity for binding to ribosomes, and the formation of initiation complex was dependent on protein initiation factors, GTP, mRNA, and aminoacyl-tRNA. The complex directed protein synthesis upon the addition of elongation factors. mRNA was treated with phosphatase and phosphorylated at the 5'-end with [(32)P]cyanoethylphosphate. [(32)P]mRNA was digested by T1 ribonuclease to completion and chromatographed on DEAE-cellulose. The only fragment with (32)P was 15 nucleotides long; it was treated with pancreatic ribonuclease and fingerprinted. Fractions of AC, AAC, and AAAC were found. Initiation signal AUG or GUG in these mRNAs does not begin immediately at the 5'-end and may be at a distance greater than 15 nucleotides. Alkaline hydrolysis of mRNAs labeled in vivo with [(14)C]adenosine revealed Ap and pppAp. Alkaline hydrolysis of mRNA labeled with (32)P at the 5'-terminus resulted in pAp. Hence, these results suggest that in a heterogeneous population of mRNAs from insects, all start with A and have sequence homology at the 5'-termini. This sequence may reflect the signal for RNA polymerase on the gene or may promote the binding of mRNA to ribosomes.
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PMID:Sequence homology at the 5'-termini of insect messenger RNAs. 435 Nov 73

After aerosolization at relative humidities of 50% or lower, encephalomyocarditis virus is rapidly inactivated. In this process the protein coat of the virion is damaged. This appears as a loss of hemagglutination activity and loss of affinity for hemagglutination inhibiting antibodies. The ribonucleic acid of the virus retains its infectivity but it becomes susceptible to ribonuclease. It sediments in sucrose gradients when centrifuged at high speed with the same velocity as free infectious ribonucleic acid extracted with phenol from intact encephalomyocarditis virus.
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PMID:Inactivation of encephalomyocarditis virus in aerosols: fate of virus protein and ribonucleic acid. 435 62

1. A simple method for the preparation of ribonuclease-free ribosomal RNA is described in which ribonuclease-deficient bacteria are treated with acetone and the RNA is extracted with phenol and purified by precipitating it with potassium acetate. The treatment with acetone appears to render the cell wall permeable to RNA but not to DNA during the extraction with phenol. The method thus avoids the need to disrupt the bacteria and greatly simplifies the subsequent purification. 2. The method has been used successfully with ribonuclease-deficient strains of Escherichia coli, Pseudomonas fluorescens and Staphylococcus epidermidis. The recovered purified RNA accounts for about 70% of the total ribosomal RNA and shows the normal sedimentation pattern of the 16s and 23s components in the analytical centrifuge.
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PMID:The preparation of ribosomal ribonucleic acid from whole bacteria. 486 33

Cells of Escherichia coli were labeled with precursors of ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein, lysed with detergent, and examined by starch-block electrophoresis and CsCl density gradient centrifugation. A large amount of the DNA was seen to remain at positions of low electrophoretic mobility and light density along with tryptophan and arginine-containing proteins and some RNA. Addition of labeled, phenol-extracted DNA to unlabeled cells prior to lysis and electrophoresis showed that only a small amount of the DNA became associated during or after lysis. Sonic treatment of a lysate removed most of the DNA to a position of electrophoretic mobility and density similar to that of free DNA, whereas pronase and ribonuclease released only a part of the DNA. We concluded that binding of DNA to cell membranes or other cell components occurs in the cell prior to lysis and involves protein and probably a specific type of RNA.
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PMID:Involvement of protein and ribonucleic acid in the association of deoxyribonucleic acid with other cell components of Escherichia coli. 487 17


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