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:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radioactive selenite reacts with purified human and goat immunoglobulins at acidic and neutral pH. The antigenic properties of the immunoglobulins are retained during the selenium labelling as shown by immunoelectrophoresis and autoradiography. Pepsin digests of 75Se-labelled IgG possess 75Se both in the (Fab')2 fraction and in the low molecular weight peptides derived from the Fc domains. Alpha-1-acid glycoprotein, ribonuclease, and lysozyme are also labelled by this procedure. Enhancement of 75Se incorporation by urea, guanidinium chloride, mercaptoethanol, sodium sulfite and carrier selenite is interpreted as an effect of destabilization of IgG disulfide bonds. Up to 1.4 g atoms Se per mol IgG have been incorporated. We assume that selenite is cleaving disulfides by a process akin to sulfitolysis. The lability of the isolated 75Se-labelled IgG to high concentrations of mercaptans and sulfite is consistent with this idea. These 75Se-labelled proteins may be useful in structure studies and radioimmunoassay.
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PMID:Reaction of selenium with immunoglobulin molecules. 1 84

The action of Armillaria mellea protease has been evaluated on a number of polypeptide substrates. It has been shown to split the Pro7-Lys8 bonds in both native and oxidised lysine-vasopressin and the Ser11-Lys12 bond in glucagon. No other splits were detected in these substrates. The enzyme also caused extensive degradation of S-carboxymethyl lysozyme, S-carcoxymethyl pepsinogen and oxidised ribonuclease. A. In each case the only new amino-terminal residue to appear was lysine. A. mellea protease was inhibited by the chelating agents 1,10-phenanthroline, alpha, alpha'-bipyridine and imidazole. The pK1 values (negative log10 of concentration required for 50% inhibition) for these three inhibitors were 3.9, 3.4 and 1.1, respectively. Lysine, S-2-aminoethylcysteine and short chain aliphatic amines also proved to be relatively good inhibitors of A. mellea protease while arginine was a poor inhibitor.
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PMID:Specificity and inhibition studies of Armillaria mellea protease. 2 49

The ultrastructural study of liver tissues from 38 patients with type B viral hepatitis consistently showed the presence of hepatitis B core antigen of 21-25 nm size in the liver cell nuclei and to a lesser extent in the cytoplasm. This finding and the demonstration of the tubular form of hepatitis B surface antigen in the proliferative degranulated endoplasmic reticulum constituted the etiologic criterion for the diagnosis of the disease. The double-shelled Dane-like particles were frequently found in association with the tubular form of the surface antigen. The core particles were found in the protoplasmic processes of hepatocytes and this correlated with the immunofluorescent microscopic findings that the antigen may be shed into circulation with the protoplasm. The core antigen was found to resist digestion by various enzymes such as protease, DNase, RNase, phospholipase C, lipase, lysozyme, diastase, neuraminidase and hyaluronidase, all of which did not destroy the immunoreactivity as demonstrated by immunoelectron and immunofluorescent microscopy. Similarly, sodium dodecyl sulfate, Tween 80 and mercaptoethanol also had no effect. The formalin-fixed paraffin-embedded liver tissue sections could be treated with protease to facilitate the immunofluorescent staining for the core antigen in tissue.
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PMID:Structural and immunoreactive characteristics of hepatitis B core antigen. 5 6

From experiments with glycoproteins containing the glycopeptide linkages, arabinose-O-hydroxyproline and galactose-O-serine (plant cell wall glycopeptides), N-acetylgalactosamine-O-serine/threonine (pig submaxillary mucin), and N-acetyl-glucosamine-N-asparagine (fetuin), it is apparent that anhydrous liquid HF, a reagent commonly used by snythetic peptide chemists for the complete removal of protecting groups from synthetic peptides, cleaves the O-glycosidic linkages of neutral sugars in 1 hr at 0 degrees C, and the O-glycosidic linkages of amino sugars in 3 hr at 23 degrees C. The N-glycosidic linkage of N-acetylglucosamine to asparagine is not cleaved under any conditions that have been tested. Sodium dodecyl sulfate gel electrophoresis of bovine serum albumin treated in HF does not show any degradation of peptide bonds. Some relatively stable enzymes (lysozyme and RNase) have been shown by others to retain most of their enzymic activity after short treatment (1 hr at 0 degrees C) in HF. With the specificity of HF at 0 degrees C for neutral sugars it should be possible to generate di- or trisaccharides in high yield from polysaccharides containing both neutral and amino sugars with neutral sugars as the reducing termini.
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PMID:A new approach to the structural determination of glycoproteins and polysaccharides: anhydrous HF solvolysis. 7 2

The distribution of ribonucleoprotein (RNP) within the mitotic spindle of newt lung epithelial cells was studied with the high voltage electron microscope (HVEM) using Bernhard's uranyl-EDTA-lead staining of thick sections in conjunction with the ribonuclease digestion of fixed cells. The results indicate that aside from ribosomes, the major RNP-containing components of the spindle are the kinetochores and centrioles, both of which stain electron-opaque after EDTA treatment. In both cases, the electron-opaque material associated with these microtubule organizing centers (MTOC's) can be removed by RNAse digestion and cold perchloric acid (PCA) extraction under conditions which leave the spindle microtubules (Mts) centrioles, and kinetochores intact. The staining reaction is not abolished by cold PCA extraction alone or by substituting other positively charged proteins (i.e., cytochrome c or lysozyme) for RNAse. The RNP component of the kinetochore is closely associated with the bases of the kinetochore microtubules. The RNP component of the centriole can be seen to surround the microtubules of the triplet blades. No evidence was found to indicate the presence of RNP in the pericentriolar material. The possible function of both kinetochore and centriolar RNP is discussed.
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PMID:Ribonucleoprotein staining of centrioles and kinetochores in newt lung cell spindles. 8 14

After lysis of Pseydomonas testosteroni with lysozyme and non-ionic detergents different DNA-protein complexes can be separated in 5-25% (w/v) neutral sucrose gradient. The protein to DNA ratio of these complexes varies between 0.5-4.5 to 1, whereby the faster sedimenting forms contain more protein than the slower sedimenting ones. Different initial rates of DNase digestion may indicate various degrees of DNA packing in these complexes. The chromosomal complexes of Pseudomonas testosteroni are relatively stable towards pronase. Treatment with RNase or sodium dodecylsulphate is accompanied by a dramatic increase in viscosity and decrease in relative density. It suggests that DNA in these complexes is maintained in its supercoiled form by RNA molecule(s) in a similar way as in isolated chromosome of E. coli.
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PMID:[Chromosomal structures of Pseudomonas testosteroni. I. Isolation and characterization of the chromosomal complexes. (author's transl)]. 13 46

The stimulatory and inhibitory activities in the crude preparation of protein kinase modulator from dog heart were separated by Sephadex G-100 gel filtration, and the stimulatory modulator was further purified by DEAE-cellulose chromatography. The isolated stimulatory modulator, as the crude modulator preparation, stimulated the activity of the purified guanosine 3':5'-monophosphate (cGMP)-dependent protein kinases of both mammalian and arthropod origins in the presence of cGMP. The cGMP-dependent protein kinases were not activated by cGMP in the absence of either the isolated stimulatory modulator or the crude modulator. The stimulatory modulator, unlike the crude modulator had no effect on the activity of adenosine 3':5'-monophosphate (cAMP)-dependent protein kinase. The stimulatory modulator was a protein since its activity was destroyed by trypsin but was resistant to hydrolysis by DNase, RNase, phospholipase C, and lysozyme. The isolated inhibitory modulator, presumably the same as the protein inhibitor of cAMP-dependent protein kinase reported by Walsh et al. (Wash. D.A., Ashby, C.D., Gonzalez, C., Calkins, D., Fischer. E.H., and Krebs, E.G. (1971) J. Biol. Chem. 246, 1977-1985), depressed the cAMP-stimulated activity of cAMP-dependent protein kinase as did the crude preparation of protein kinase modulator. The isolated inhibitory modulator, unlike the crude preparation, was without effect on cGMP-dependent protein kinase. The present findings provide evidence to support that in mammals there are separate proteins for the stimulatory and the inhibitory activities of protein kinase modulator, in contrast to the modulator from an arthropod tissue (lobster tail muscle, Donnelly et al. (Donnelly, T.E., Jr., Kuo, J.F., Reyes, P.L., Liu, Y.P., and Greengard, P. (1973) J. Biol. Chem. 248, 190-198) which has been shown to possess both activities.
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PMID:Isolation of stimulatory modulator of guanosine 3':5'-monophosphate-dependent protein kinase from mammalian heart devoid of inhibitory modulator of adenosine 3':5'-monophosphate-dependent protein kinase. 18 22

To evaluate extracellular hydrolytic enzymes in an in vivo system, plastic chambers were glued over rabbit dermal BCG lesions in various stages of development, after the central epithelium was removed with a scalpel. They were filled with tissue culture medium and left in place 2 days. The following enzymes in the fluid were assayed: collagenase (an enzyme secreted but not stored in macrophages); lysozyme (both secreted and stored); DNase and RNase (released on cell death and possibly regurgitated but not secreted); and, as a control, lactic dehydrogenase (released only on cell death). Tissue sections were prepared and studied histologically for the type of cell infiltrate, for beta-galactosidase (our marker enzyme for macrophage activation), and for necrosis. At 11 and 18 days of age the BCG lesions were largest and the number of activated macrophages in the chamber beds was highest. At this time the levels of the five enzymes assayed in the chamber fluids reached their peaks, tuberculin hypersensitivity was well developed, and the bacilli components would still be plentiful. In general, the chamber fluids from 11- and 18-day BCG lesions contained higher enzyme levels than chamber fluids from tuberculin reactions. Active collagenase was only detected in fluids from such BCG lesions. Evidently, the serum in the chamber fluids was sufficient to inhibit the lower amounts of collagenase probably released from smaller BCG lesions and tuberculin reactions (and from the 2-week polystyrene lesions that were also evaluated). These studies demonstrate that in chronic inflammatory reactions, both acid-acting and neutral-acting hydrolytic enzymes are released extracellularly. Tissue components would be hydrolyzed locally wherever the acid-acting hydrolytic enzymes encounter a drop in pH and wherever the concentration of neutral-acting hydrolytic enzymes exceeds the concentration of their inhibitors.
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PMID:Extracellular hydrolytic enzymes of rabbit dermal tuberculous lesions and tuberculin reactions collected in skin chambers. 20 93

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

The protein spin-echo decay and recovery of longitudinal magnetization were studied in seven globular proteins: cytochrome C, ribonuclease, lysozyme, DNA, hemoglobin, serum albumin and gamma-globulin in D2O solutions. For comparison the Tobacco mosaic virus (TMV) protons in D2O solutions were also investigated. The spin-echo decay of all 7 proteins can be separated into three components: a slowly decaying component with an amplitude of about 10% of the amplitude of the total signal, intermediately and fastly decaying components, the two latter being comparable in amplitudes. Longitudinal relaxation is more simple in character. The value of T2 of the protons responsible for the fastly decaying components in linearly dependent on the molecular weight of the protein, a fact indicating that the regions of the proteins with a "rigid" structure can be responsible for this component. The intermediate component, whose contribution increases with temperature, was ascribed to the mobile regions of the protein, and the slowly decaying component to the mobile protein side chains. Weak dependence of T1 on the protein molecular weight and some other obtained data give additional evidence for the presence of motion within macromolecules. The peculiarities of this motion is in good correspondence with the notion about the existence of the segmental motion of the polypeptide chain (conformational mobility of the protein). In contrast to proteins the spin-echo decay of TMV lacked the slow component and the "solid" echo signal was observed which indicates the existence of a "rigid" structure in the macromolecules of the virus.
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PMID:[Study of the conformational mobility of globular proteins by pulse methods of NMR]. 20 75


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