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)

By sequential acid treatment, gel filtration and KM-cellulose sorption a 18--20-fold purified preparation of ribonuclease with a yield of 50--60% was obtained from the culture liquid filtrate of Actinomyces rimosus 994. The preparation had a high specific activity of 450,000--600,000 units/mg protein, contained 85--98% protein, insignificant amounts of carbohydrates and hydroxytetracycline, and no quantities of DNase, phosphomonoesterases, phosphodiesterase or proteases. In RNA degradation (preparation of the total yeast RNA of the Sigma Co.) optimal results were obtained at 50 degrees C and pH 7.0--7.2 in phosphate buffer and 7.6--8.0 IN Tris-HCl buffer. The preparation was stable at high temperatures (80--100 degrees) in the wide pH range and during storage in the lyophilized form and in buffer solutions. RNase effect was inhibited by zinc, copper, iron and cobalt cations and activated by beta-mercaptoethanol, citrate and EDTA. Protamine sulphate and urea in low concentrations (0.01% and 1--4 M, respectively) accelerated and in high concentrations (1% and 8 M, respectively) terminated the enzyme reaction. With respect to many properties RNase from Act. rimosus 994 was similar to extracellular RNases, produced by other actinomycetes and fungi.
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PMID:[Preparation of extracellular ribonuclease form Actinomyces rimosus 994]. 3 16

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.
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PMID:Histochemistry of the keratohyalin granules in human oral leukoplakia. 5 23

In 56 patients with Hodgkin's disease, the following bloodtests were carried out: erythrocyte sedimentation rate (ESR), fibrinogen, alpha2-globuline, serium iron concentrations and alkaline phosphatase activity. In some patients we additionally measured alkaline leucocyte phosphatase and serum ribonuclease activity. In our series ESR, serum iron and alpha2-globuline concentrations were the most sensitive metabolic parameters. A rise in fibrinogen concentration, alkaline phosphatase and serum ribonclease activity seems to indicate extensive disease. It is not possible, however, to discern between a state of remission and stage I by means of these parameters. ESR, serum iron and alpha2-globuline concentrations might be either elevated or normal in both instances. These parameters seem important in order to distinguish between a remission or stage I on the one hand and extensive disease in stage III and IV on the other hand. Concomitant findings of ESR above 40 mmh, elevated concentrations of fibrinogen and alpha2-globuline, as well as elevated alkaline phosphatase and serum and serum ribonuclease activity mostly indicate stage III or IV.
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PMID:[Significance of metabolic parameters in Hodgkin's disease (author's transl)]. 5 79

It seems from the literature that colloidal iron (C.I.) binding sites on cell surfaces cannot be completely removed by treatment with Vibrio Colerae alpha-neuraminidase. We wondered if C.I. particles bind to negative groups other than the carboxyl groups of sialic acids. Using HeLa cells from suspension cultures and fresh human erythrocytes, we examined, with the transmission electronmicroscope, the influence of the following enzymatic and histochemical treatments on C.I. staining: alpha-neuraminidase; hyaluronidase; ribonuclease; alpha-amylase; mild methylation (MM); MM + saponification (Sap.); MM + Sap +MM; MM + Sap + alpha-neuraminidase; active methylation (AM); AM + Sap; AM + Sap + AM; AM + Sap + alpha-neuraminiadase; CH3OH (80%); Sap. It seemed from these experiments that the carboxyl groups of alpha-neuraminidase sensitive sialic acids constitute the majority of binding sites for C.I. to these particular cells. The most interesting candidates for the residual binding of C.I. are carboxyl groups of alpha-neuraminidase resistant molecules, sulfon, sulfin, and sulfate groups.
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PMID:Cytochemistry of colloidal iron binding to the surface of Hela cells and human erythrocytes. 6 32

Mouse 3T3, Simian virus 40 transformed 3T3 cells (SV3T3) and two SV3T3 lines showing reversion of their transformed phenotype (Rev 3 and Rev 5) have been studied with respect to electrophoretic mobilities and colloidal iron hydroxide (CIH) binding density visible by electron microscopy, before and after incubation with neuraminidase or ribonuclease. The results show that, in general, the marked changes in both sets of surface parameters associated with transformation are largely reversed in the Rev 5 revertant, and only partially reversed in the Rev 3 line. It was also observed that, in common with Ehrlich ascites tumor (EAT) cells examined previously, the densities of CIH-particles bound over the microvilli of all the cell types was 1.5 to 2.7 times higher than those bound to the spaces between them. In contrast to the EAT cells, the higher density of CIH particles bound over the microvilli was not due to neuraminidase-sensitive binding sites.
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PMID:Some electrical properties of the peripheries of murine 3T3 cells with respect to viral transformation and reversion. 17 59

This paper demonstrates the existence of regions in eight small globular proteins in which the side chains of sulfur-containing amino acids (cysteine and methionine) alternate in space with side chains of aromatic amino acids (histidine, phenylalanine, tryptophan and tyrosine). The proteins are: rubredoxin, high potential iron protein, cytochrome c, flavodoxin, deoxyhemoglobin, trypsin inhibitor, ribonuclease-S, and lysozyme. The sulfur-pi-bonded 'chains' involve a minimum of five and a maximum of 10 amino acids, and contain the most polarizable atoms within proteins. S-pi-chains give extra stability to the folding of proteins; they may also afford paths for the step-wise movement of electrons.
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PMID:Chains of alternating sulfur and pi-bonded atoms in eight small proteins. 20 19

We have investigated the pathogenesis of the polyclonal hypogammaglobulinemia associated with BALB/c plasmacytomas TEPC-183 and SPQC-11 to gain insight into the hypogammaglobulinemia observed in human myeloma. With pokeweed mitogen-driven IgM biosynthesis by mouse splenocytes as the indicator system for suppression, we found that a protein extract of asscites cells obtained from these tumor-bearing animals could suppress immunoglobulin production, whereas like extracts from a non-suppressing plasmacytoma, modified RPC-5, caused no suppression in vitro. Extracts of tumor ascites depleted of mononuclear phagocytes by iron carbonyl treatment showed little suppressor activity. The active extract was not cytotoxic and contained no mycoplasma or common murine viruses. Furthermore, the active suppressor factor appears to be a low m.w. protein that is not affected by treatment with ribonuclease. These results and others are consistent with the idea that the hypogammaglobulinemia of myeloma is due to the formation of immunoregulatory macrophage-like cells which synthesize a suppressor substance.
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PMID:Hypogammaglobulinemia in experimental myeloma: the role of suppressor factors from mononuclear phagocytes. 85 68

To assess whether myoglobin adversely affects renal adenylate pools, rats were infused with purified myoglobin (50 mg/100 g body wt) for two hours and renal ATP, ADP, and AMP levels were measured in the absence of shock, after 25 minutes of hemorrhagic shock (55 to 60 mm Hg) or 30 minutes post-recovery. In the absence of shock, myoglobin lowered ATP by 24% (assessed 65 min post-infusion) without affecting renal blood flow (RBF). This effect was completely blocked by deferoxamine (DFO) treatment and it could not be reproduced by ribonuclease infusion (a non-Fe containing, but filtered, protein). Myoglobin + shock caused a three- to fourfold greater decline in ATP than did shock alone despite comparable RBFs. Shock plus myoglobin, but neither one alone, induced substantial S1/S2 proximal tubular morphologic damage and a severe reduction in creatinine clearance, confirming synergistic injury. Ribonuclease completely reproduced myoglobin's effect on shock-induced adenylate profiles. DFO +/- hydroxyl radical scavenger therapy (Na benzoate) did not block the myoglobin shock effect on adenylate pools. Post-shock adenylate recovery was not compromised by myoglobin pre-treatment. If renal artery occlusion (RAO), rather than shock, was used as the ischemic challenge, myoglobin had no discernible impact on adenine nucleotide content. This study concludes that: 1) myoglobin modestly lowers baseline adenylate pools due to an Fe dependent mechanism; 2) myoglobin drastically accentuates shock-induced adenylate depletion by a non-hemodynamic/non-Fe dependent mechanism; 3) myoglobin nephrotoxicity cannot be attributed solely to tissue iron loading; and 4) the RAO model can completely mask important influences on ischemic cellular energetics.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Myoglobin depletes renal adenine nucleotide pools in the presence and absence of shock. 200 25

Multiple forms of lactoferrin (Lf) were detected in granulocytes isolated from normal individuals and patients with granulocytic leukemias. One class of Lfs bound iron; a second class did not bind iron but possessed potent ribonuclease activity. The different forms of Lf were similar, if not identical, in their physical, chemical, and antigenic properties. The multiple forms of Lf may relate to the various functions ascribed to the molecule.
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PMID:Multiple forms of lactoferrin in normal and leukemic human granulocytes. 220 56

K562 human erythroleukemia cells can be induced to make hemoglobin by a variety of inducing agents. Most of these agents are effective in media supplemented with fetal bovine serum (FBS), but not in media supplemented with newborn bovine serum (NBS). The active factor in FBS has an apparent molecular weight of 30,000 daltons and appears to be a protein on the basis of the following properties: lability at 100 degrees C, inactivation by desferrioxamine plus trypsin, resistance to periodate, and resistance to ribonuclease. Media containing NBS can be used for induction if supplemented by either this factor or transferrin of bovine or human origin. The small size of the active factor (mol. wt. approximately 30,000 daltons) indicates that it is not identical to bovine transferrin (mol. wt. approximately 77,000 daltons). However, when iron-saturated bovine transferrin is digested with trypsin, the peptide fragments produced resemble the FBS factor in activity, size, and reaction with antibovine serum transferrin.
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PMID:K562 cell erythroid differentiation: requirement for a factor in fetal bovine serum. 392 91


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