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)

The homology of angiogenin and pancreatic RNase A provides a compelling reason to systematically compare the characteristics of the two proteins using the chemical modification approaches that proved essential to understanding the action of RNase. Reagents specific for histidine, lysine, and arginine markedly decrease the ribonucleolytic activity of angiogenin, much as has been observed for RNase A. Activity is abolished by reduction of the disulfide bonds and is restored by reoxidation. Methionine, tyrosine, and carboxyl group reagents have no significant effect. From the point of view of reactivity, the histidine and lysine residues in angiogenin are severalfold less susceptible to modification than those in RNase A. Arginine reagents, on the other hand, inactivate angiogenin considerably faster than RNase A. Considering specificity, bromoacetate inactivates angiogenin at pH 5.5 by modifying 1.5 histidines, but lysine and arginine reagents are less specific. Thus, 3.8 and 6.3 residues, respectively, are modified by 1-fluoro-2,4-dinitrobenzene and by formaldehyde plus cyanoborohydride, under conditions where activity decreases by approximately 80% in both cases. With phenylglyoxal, 6.7 arginines are lost when there is 92% inactivation. Poly(G) prevents inactivation by lysine and arginine reagents, and phosphate protects against the effects of lysine modification. Thus, the functional consequences of these modifications likely reflect the loss of critical residues rather than general conformational effects.
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PMID:Ribonucleolytic activity of angiogenin: essential histidine, lysine, and arginine residues. 312 7

Yeast cells, Candida utilis, in water suspension and in the absence of electrolytes were found to be very sensitive to several proteins of moderate size, including ribonuclease, protamine, lysozyme, bovine serum albumin, cytochrome c, and myoglobin. Viability ceases rapidly, and ultraviolet-absorbing compounds (260 mmu) and the amino acid pool are released into the medium. The ultraviolet-absorbing material appears to be the nucleotide and coenzyme fraction usually extracted by 0.2 n perchloric acid at low temperature. The ribonucleic acid fraction remains in the cell ghosts and can be released by ribonuclease. The enzymatic properties of some of these proteins have no relation to their damaging effect on the cell membrane. Poly-l-lysine shows the same activity.
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PMID:Effect of some proteins on the yeast cell membrane. 429 20

Poly(U) binds to globin mRNA in 0.1m-NaCl. Studies with ribonuclease digestion of this complex suggest that there are polyadenylate-rich sequences in the mRNA containing about 30-40 adenylate residues. The sequences appear to be homogenous and of approximately the same length for both alpha- and beta-globin mRNA. They are most likely located at the 3' terminus of the molecule.
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PMID:Interaction between polyuridylic acid and rabbit globin messenger ribonucleic acid. 435 10

The location of poly(A) sequences in the RNA of mammalian RNA-tumor viruses was determined by enzymatic analyses. The 56-64S viral genomic RNAs, the 20-40S viral subunit RNAs, and the 4-5S poly(A) sequences excised from these viral RNAs were subjected to either hydrolysis with a 3'-OH specific exoribonuclease from Ehrlich ascites tumor cells or phosphorolysis from the 3'-termini with polynucleotide phosphorylase from Micrococcus luteus. Purified adenosine-labeled poly(A) fragments, excised from genomic viral RNAs by RNase A and T(1) digestion, were hydrolyzed with the 3'-OH specific exoribonuclease for various periods of time. Poly(U) filter binding studies of the residual poly(A) indicated that 97% of the poly(A) fragments were hydrolyzed. Adenosine-labeled genomic and subunit viral RNAs and excised poly(A) fragments were phosphorolyzed from their 3'-termini for various periods of time with polynucleotide phosphorylase. The degree of phosphorolysis was monitored by poly(U) filter binding studies, and CCl(3)COOH insolubility and solubility determinations. There was an initial preferential rate of phosphorolysis of the poly(A) sequences of genomic and subunit viral RNAs as compared to the total adenosine-labeled viral RNAs. The data from these two different enzymatic mechanisms of action indicated conclusively that the poly(A) sequences were located at the 3'-termini of genomic and subunit viral RNAs.
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PMID:Polyriboadenylate sequences at the 3'-termini of ribonucleic acid obtained from mammalian leukemia and sarcoma viruses. 437 12

Poly(A) polymerase activity is induced during vaccinia virus infection of HeLa cells. The enzyme is maximally induced at 3.5 h postinfection. Partial purification frees the preparation of RNase activity and RNA polymerase activity. ATP is the substrate for poly(A) synthesis. A small amount of poly(A) is produced from added adenosine diphosphate due to the production of ATP by an adenylate kinase present in the preparation. The incorporation of ATP into poly(A) is dependent on divalent cations (Mg(2+) or Mn(2+)) and is not inhibited by UTP, CTP, or GTP. Poly(U) stimulates ATP incorporation; poly(A) and poly(C) have little effect on ATP incorporation, and poly(dT) is extremely inhibitory. RNA prepared from HeLa cells and from the partially purified poly(A) polymerase (the enzyme preparation contains endogenous RNA [Brakel and Kates]) stimulates ATP incorporation by poly(A) polymerase which was subjected to DEAE-cellulose chromatography. RNase's, pancreatic and T(1), inhibit the production of poly(A). DNase has little effect. Poly(U) is able to stimulate poly(A) production in the presence of T(1) RNase.
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PMID:Poly(A) polymerase from vaccinia virus-infected cells. I. Partial purification and characterization. 441 6

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

Concanavalin A, endotoxin, poly I: C, and tumour necrosis serum (TNS) were compared for antitumour activity against Meth A sarcoma transplanted in syngeneic BALB/c mice and their capacity to induce tumour necrosis factor (TNF), heat-stable cytostatic factors, and heat-labile interferon in the blood of normal and Corynebacterium parvum-pretreated mice. All the agents induced hyperemia and inhibition of mitosis at 4 h, and by 24 h many tumours had a dark necrotic centre. Subsequent tumour growth was inhibited and in some of the treated mice tumours regressed completely. Poly A: U and normal mouse serum did not induce regression and their effects were less marked in all other respects, suggesting that these events may be linked. The necrotizing effects of concanavalin A and poly I: C are unlikely to be mediated by TNF, because neither agent could mimic endotoxin in eliciting RNase-resistant necrotizing and regressing activity in the serum of mice pretreated with C. parvum. Poly I: C did not induce strong cytostatic activity in the sera of C. parvum-treated mice, and for this and other reasons these factors are unlikely to be responsible for the observed effects. Concanavalin A, endotoxin, and poly I: C induced high levels of serum interferon but purified interferon had only weak antitumour activity in the Meth A system, suggesting that interferon may not be the mediator. From these and other data it is concluded that there is no clear relationship between the capacity of the agents to induce tumour necrosis and their capacity to elicit TNF, cytostatic factors, and interferon.
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PMID:Antitumour activity of endotoxin, concanavalin A and poly I: C and their ability to elicit tumour necrosis factor, cytostatic factors, and interferon in vivo. 619 6

The possible synthesis of RNA located in the extracellular compartment of Bufo arenarum gastrula was studied using a biochemical method. [3H]adenosine was microinjected into the blastocoel of late blastulae or early gastrulae, which were then dissociated at advanced gastrula stage. RNA was extracted from both, the cellular supernatant and the disaggregated cells, by the Kirby-phenol procedure. Most of the ethanol-precipitable radioactivity was sensitive to RNase and alkaline treatment. The partial characterization of these molecules indicate that the radioactive pattern of total RNA, found in sucrose gradients, the ratio Poly(A)+RNA/Poly(A)-RNA as well as the radioactive pattern of Poly(A) fraction in acrylamide gels were different in samples from cellular and from extracellular origin. Although not conclusive, these results are proposed as a new argument for the existence of an extracellular RNA in the amphibian embryo.
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PMID:Newly synthesized extracellular ribonucleic acids in the amphibian gastrula. 619 95

Poly-[C]-specific ribonuclease (RNase) is released in large amounts from rat pancreas incubated at 37 degrees C in isotonic saline solution. Pancreatic cell disruption by homogenization releases only 10% of that RNase. The remainder, perhaps membrane-bound, is freed only after further membrane deterioration during anoxic incubation. Other tissues (small intestine, stomach, colon, liver, spleen, kidney, muscle, and skin) do not appear to contain much of this RNase or to release it during anoxic incubation. Relatively little amylase is released from the pancreas under the conditions that release RNase. The findings provide a rational basis for monitoring serum RNase levels in patients with acute pancreatitis for early detection and treatment of pancreatic necrosis in man.
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PMID:Release of ribonuclease from anoxic pancreas. 620 Sep 44

A CSF Poly(C)-avid ribonuclease (RNase) activity was determined in serum and CSF of 11 controls and 75 neurological patients (34 multiple sclerosis (MS), 18 infectious processes and 23 other neurological diseases (OND]. In controls, the blood-CSF ratio of RNase activity is low. This fact and the absence of correlation between serum and CSF RNase activity (except in OND group), and between CSF albumin and CSF RNase activity in controls and MS patients, suggest an intrathecal origin for the major part of this CSF RNase activity. A formula taking into account any plasmatic enrichment in RNase of the CSF is proposed to evaluate this intrathecal activity. The normal mean value of this intrathecal RNase activity is 27 +/- 3 units/ml (mean +/- SE) in our experimental conditions and using our formula. The highest intrathecal RNase activity is observed in infectious processes and this finding is associated with a significant increase in the local anti-RNA antibody synthesis. An increase in intrathecal RNase activity is rarely found in MS and local anti-RNA synthesis is only observed in one third of MS patients.
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PMID:Intrathecal origin of CSF ribonuclease. Differences between infectious processes of the nervous system and multiple sclerosis. 620 80


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