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)

Two RNases in bound forms associated with the microsomal membrane and with the ribosomes or unknown particles in pea root tissue were solubilized by subjecting the membrane to sonic oscillation in the presence of EDTA and KC1 and by treating the particles with EDTA, respectively. The RNases were than purified by DEAE-cellulose and Sephadex G-75 column chromatographies. The elution profiles of RNases from the columns were very similar. No significant differences were observed in their electrophoretic mobilities in polyacrylamide gels, in molecular weight, in activation by inorganic ions, urea or phospholipid micelles or in the dependence of their activities upon pH. The purified RNASES were not different from the bound enzymes as regards activation by inorganic ions and urea and the dependence of the activity upon pH. Triton X-100 stimulated the activity only if RNase was in a bound form associated with the microsomal membrane. We propose that the two RNases may be the same molecular species and differ only in the form of association with intracellular structures.
J Biochem 1975 Sep
PMID:Purification and properties of two ribonucleases in different intracellular compartments in pea root tissue. 0 8

A ribonuclease, purified 2500-fold from human liver, was found to be inactive against synthetic homopolynucleotides, whereas synthetic co-polymers containing adenylic acid were rapidly degraded. The specificity of the RNase is unique in that only purine residues, in a 5:4 ratio of guanylic to adenylic acid, are found at the 5' termini of the degradation products of yeast RNA. No specificity was observed at the 3' termini of the fragments. When analyzed by DEAE-cellulose chromatography, approximately 80% of the oligonucletoides were 4 to 11 residues in length. The hydrolysis of RNA by the liver enzyme, when examined in low ionic strength buffer, could be increased severalfold over control levels by the addition of polyamines. The enzyme was found to exist as two distinct species on sucrose gradients, with molecular weights of 128,000 and 14,000. However, the addition of spermidine to the gradients resulted in the recovery of all the enzyme activity as the smaller species. The polyamines were also shown to reverse the inhibition of the enzyme by the ordered polynucleotides, polyguanylic acid and polyadenylic acid. Inhibition of enzyme activity by the polyadenylic acid segment of various mammalian mRNAs was also demonstrated.
J Biol Chem 1976 Sep 25
PMID:Properties of a human liver ribonuclease. Inhibition by polynucleotides and specificity for phosphodiester bond cleavage to yield purine nucleosides at the 5' termini. 0 99

The presence of an RNA-dependent RNA polymerase is demonstrated in purified rotavirus particles. Optimum polymerase activity was found between 45 to 50 degrees C, at pH 8, and in the presence of 10 mM-magnesium ions. The polymerase product was highly sensitive to pancreatic RNase (97%) in low or high salt concentration. The enzyme was activated by EDTA treatment of intact particles or heat shock. The similarities between reovirus, blue-tongue virus and rotavirus polymerases are discussed.
J Gen Virol 1977 Sep
PMID:Ribonucleic acid polymerase activity associated with purified calf rotavirus. 2 Dec 25

Four temperature bacteriophages (designated as PF1, PF2, PF3 and PF4) were isolated from lysogenic strains of Clostridium perfringens type A. On the basis of plaque morphology, pH stability, DNase and RNase resistance, buoyant density, one-step growth parameters and electron microscope phage dimensions, it seems that these phages are different and unrelated. Calcium was required for better phage replication. Bacterial strain S107 appears to be the only UV-inducible strain as compared with the other three lysogenic strains. PF2 has a unique pattern of pH stability showing two optima values: one at pH 5 and the second at pH 8-9. Generally, all four phages have a better resistance in acid than in alkaline pH values. The CsC1 equilibrium centrifugation patterns reveal low figures for phage PF1, PF2 and PF3 and show off the fact that PF4 lysates contain two viral particules different with respect to their densities, a property which other determinations failed to demonstrate. Each phage, except PF4, is well characterized by the parameters of the one-step growth cycle.
Rev Can Biol 1977 Sep
PMID:Properties of four temperate bacteriophages active on Clostridium perfringens type A. 2 5

Escherichia coli, strain AB 1157, cells are capable of translating human, mouse, and chicken messenter RNA for interferon with production of interferon of the corresponding specifity. This translation occurs in the presence of serum. The activity of the resulting interferon decreased in parallel to dilution of the original mRNA preparation, upon multiple ulitization of the mRNA solution, as well as upon reduction of the interferon- producing activity of cells-donors of mRNA due to prolonged storage of the cells. Unlike animal cells, the bacteria do not require pre-treatment with actinomycin D. The interferon translated by bacteria is inactivated by trypsin and resistant to ribonuclease.
Acta Virol 1977 Sep
PMID:Translation by bacterial cells of messenger RNA for interferon of animal origin. 2 28

Infectivity of DNA isolated from L cells chronically infected with SV5 paramyxovirus was demonstrated by inoculation of continuous RH and HEp-2 cells. Infectivity of the DNA was completely abolished by treatment with deoxyribonuclease or by alkaline hydrolysis but did not change after treatment with ribonuclease and specific anti SV5 serum. The virus obtained as a result of transfection caused haemadsorption in susceptible cells and was neutralized by specific antiserum like the prototype SV5 strain.
Acta Virol 1977 Sep
PMID:Infectivity of DNA recovered from cells persistently infected with SV5 paramyxovirus. 2 36

An immobilized enzyme (pancreatic ribonuclease bound to porous titania) was investigated for the degradation of purified yeast ribonucleic acid as a substrate. The immobilized enzyme is active and stable in the pH range 4--8. Dependence of enzymatic activity on ionic strength, pH, temperature, fluid flow rate, and substrate concentration were investigated. A cumulative fluid residence time of 6 sec is sufficient for 50% substrate conversion at 25 degrees C and pH 7.0. The critical flow rate (i.e., the fluid flow rate necessary to remove film diffusion resistance) approximately doubles with each 10 degree C rise in reaction temperature. The critical flow rates obtained in this study are about 40 times greater than those obtained for a similar study on immobilized glucose oxidase. Arrhenius plots gave activation energies of -9.6 and -7.1 kcal/g mol at pH 4.6 and 7.0, respectively. The work reported herein is a bench-scale investigation of an immobilized enzyme with primary emphasis on the mass transfer and kinetic characteristics of the system. The rapid reaction rates obtainable at relatively low temperatures offer a potential alternative method of purifying yeast single cell protein (SCP) with miminum loss of desired protein. The key questions are how such a system would react in a yeast homogenate, what conditions in such a system must be controlled, and what type of immobilized reactor should be utilized, if such further work continued to show promise.
Biotechnol Bioeng 1979 Sep
PMID:Degradation of ribonucleic acid by immobilized ribonuclease. 4 Jun 30

Ethyl bromoacetimidate was designed as a potential reagent for cross-linking protein NH2 groups with a vicinal nucleophile. The chemical properties of this compound were studied by model reactions with small molecules. Ethyl bromoacetimidate amidinates lysine residues in ribonuclease at pH 9. In a second step, at lower pH values, one of the bromoacetamidino groups bound to the enzyme alkylates a proximal histidine residue. This substitution is pH-dependent with a sharp optimum at 5.6, the same as was earlier observed for alkylation of histidine-119: histidine-12 by halogenoacetates and halogenoacetamides. A common mechanism is suggested for all these types of alkylation. Ethyl bromoacetimidate thus appears as a short-distance crosslinker which can be used, for example, to explore chemically the microenvironment of an essential lysine residue of an enzyme within the active site.
Hoppe Seylers Z Physiol Chem 1979 Sep
PMID:Ethyl bromoacetimidate, a NH2-specific heterobifunctional reagent. Model reactions with ribonuclease. 4 7

Conventional methods (i.e. gradient centrifugation) for the purification of oncornaviruses are usually not effective in complete removal of nonviral proteins. Such contaminants often prove to be a nuisance in subsequent immunological or biochemical studies. Hyperimmune sera prepared from these viruses must be absorbed to assure specificity; cell-derived proteins can be shown to interfere with studies of virus structural proteins, nucleic acids, or viral enzymes. Herein is described a method for removal of most of these contaminants. Viruses are diluted in a high concentration of NaCl to achieve a final concentration of 15%, incubated for 30 min, sedimented, and resuspended in buffer. This procedure results in reductions of up to 48% of the protein without affecting particle count. Immunological, biochemical, and biological properties are not adversely affected. Of the proteins removed, fetal calf serum components and a ribonuclease (presumably cell-derived) were identified. This technique differs significantly from other high-salt methods in that the virus is not precipitated from suspension. It is believed that absorbed proteins are desorbed and left in solution (or suspension) as the virus is sedimented by centrifugation.
J Clin Microbiol 1975 Sep
PMID:New method for the removal of extraneous proteins from purified oncornaviruses. 5 58

The keratohyalin granules from 25 human oral leukoplakias, showing benign hyperorthokeratosis histologically, were examined employing a series of histochemical techniques. The tissues were fixed in 10% neutral buffered formalin, 80% methanol, or Carnoy's fluid. The keratohyalin granules stained intensely with Pauly's reagent, Congo red and Harris hematoxylin, indicating the presence of proteins. This was confirmed by abolishing the staining reaction by pretreatment with proteolytic enzymes. The keratohyalin granules also reacted with methyl green-pyronin by staining pink at their peripheries; this staining was abolished by pretreatment with ribonuclease, indicating the presence of ribonucleotides. The keratohyalin granules partially stained with toluidine blue and colloidal iron, indicating the presence of acid polysaccharides. The keratohyalin granules did not react with the Feulgen reagent, suggesting the absence of DNA. Our studies indicate that the keratohyalin granules in human oral leukoplakia are primarily protein(s) complexed with polyribonucleotides. The presence of a carbohydrate moiety suggests the possibility of a protein-polysaccharide component in the granules.
J Oral Pathol 1975 Sep
PMID:Histochemistry of the keratohyalin granules in human oral leukoplakia. 5 23


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