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)

Supernatant fluids from murine spleen cell cultures incubated with concanavalin A for 48 hr contain a factor(s), soluble immune response suppressor (SIRS), which suppresses plaque-forming cell responses to sheep erythrocytes by murine spleen cells in vitro. In the present studies, some of the biochemical and biophysical properties of SIRS were investigated. SIRS was non-dialysable; the suppressive activity was stable at 56 degrees C for 30 min, but was destroyed by treatment at 70 degrees C for 30 min, 80 degrees C for 10 min, or at pH 2. The suppressive activity was not absorbed by the stimulating antigen, SRBC, or antisera against murine IgG or mu-chain, suggesting that SIRS does not contain immunoglobulin determinants. Murine spleen and thymus, but not kidney cells, however, absorbed SIRS activity. Enzyme treatments revealed that SIRS was resistant to DNase and RNase, but was destroyed by trypsin and chymotrypsin. In gel filtration with Sephadex G-100, SIRS activity eluted in the fraction corresponding to m.w. in the range between 48,000 and 67,000. With polyacrylamide gel electrophoresis, SIRS activity migrated in the region cathodal to albumin. Isopycnic centrifugation in a cesium chloride gradient suggested that SIRS is a glycoprotein. These supernatant fluids with SIRS activity were also found to contain macrophage migration inhibitory factor (MIF). In the experiments using gel filtration, polyacrylamide gel electrophoresis, and isopycnic centrifugation to fractionate supernatant fluids, SIRS and MIF activity were found in the same fractions, and to date we have been unable to dissociate definitively SIRS activity from MIF activity.
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PMID:Biological expressions of lymphocyte activation. V. Characterization of a soluble immune response suppressor (SIRS) produced by concanavalin A-activated spleen cells. 0 95

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

Human urine RNase was purified about 2000-fold. The preparation is free from phosphatase, phosphodiesterase and DNase activities. On electrophoresis through polyacrylamide gel at pH 8.3, it migrates toward the anode and stains with periodic acid-Schiff reagent, suggesting that it is acidic and glycoprotein in nature. Its isoelectric point is at pH 4.1. It has a molecular weight of about 21,500. It is thermostable at pH 4.2 and thermolabile at pH 8.5. It has a pH optimum at 6.5. It exhibits highest preference for cytidine 3'-phosphate linkages. Its activity on poly (C) is endonucleolytic. It cleaves poly (C) via intramolecular transphosphorylation. It has no action on cytidine 2': 3'-cyclic phosphate or uridine 2':3'-cyclic phosphate. Its rate of hydrolysis of poly (U) is less than 2% of that of poly C). Poly (A) and poly (G) are totally inert to its action. Its action on poly (C) is inhibited by poly (G), poly (A) and poly (U). It differs from bovine pancreatic Rnase A in its physical, chemical and catalytic properties. It is, however, similar to human serum and pancreatic RNase in all its properties, suggesting that pancreas is its likely source.
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PMID:Purification and properties of a ribonuclease in human urine that hydrolyses polycytidylic acid. 2 Jun 15

220-MHz NMR was used to observe the titration behavior of the 5 histidine residues in porcine pancreatic ribonuclease (ribonucleate pyrimidine-nucleotido-2'-transferase (cyclizing), EC 3.1.4.22) and a derivative prepared by removal of 80% of the attached carbohydrate from this glycoprotein. Resonances due to histidine C-2 protons were observed over the full pH range for 3 of the residues; such resonances for the remaining 2 histidine residues broadened out as the pH was increased. Resonances due to histidine C-4 protons were also observed for 2 of the residues. The titration curves for both proteins were identical within experimental error. Resonances were assigned by comparison with histidine NMR titrations in ribonucleases from other species. Histidine 105, immediately adjacent to the site of attachment of a heterosaccharide side chain, has a C-2 proton chemical shift and pK that are insensitive to the large alteration in the bulk of the carbohydrate side chain. The chemical shifts of the C-2 proton of histidine 48 and of the C-4 proton of histidine 80, histidine residues that are close to one another and to another heterosaccharide side chain, show a similar insensitivity. The observations are direct evidence in support of the thesis that the heterosaccharides in porcine ribonuclease project away from the surface of the protein into the solution environment.
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PMID:A comparison by 220-MHz NMR of histidine hydronium ion titrations in porcine pancreatic ribonuclease and an extensively deglycosylated derivative. 3 80

An acid ribonuclease has been purified from HeLa cell lysosomes. The specific activity of the RNase in lysosomes is 8-fold higher than that in nuclei and 15-fold higher than that in the postlysosomal fraction. The purified enzyme showed no detectable DNase, phosphodiesterase, phosphatase, or alkaline RNase activity. The acid RNase binds to Con A-agarose and is inferred to be a glycoprotein. It has a low isoelectric point at pH 3.0 to 3.5, and the optimal pH for activity is between 5.0 and 5.5. The enzyme requires no divalent cation for optimal activity and is totally inhibited by 1 mM Cu2+ or Hg2+. Monovalent cations including Na+, K+, and NH4+ stimulate the activity in low ionic strength buffer. The enzyme degrades rRNA faster than tRNA, and tRNA faster than poly(U); poly(A) and poly(C) are highly resistant. The products from rRNA are mostly oligonucleotides with 3'-phosphate ends. An acid RNase is also present in the lysosomes of L-cells grown in a medium free of serum; it is probably identical to the one described here.
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PMID:Acid ribonuclease from HeLa cell lysosomes. 3 88

Envelope-specific and sarcoma-specific nucleotide sequences have been located within the 10,000 nucleotides of the RNA of nondefective Schmidt-Ruppin Rous sarcoma virus (nd SR). For this purpose, about 30 RNase-T1-resistant oligonucleotides were ordered relative to the 3'-poly(A) terminus of the RNA, to construct an oligonucleotide map of the nd SR RNA. A cluster of seven envelope-specific oligonucleotides, identified by their absence from an otherwise very similar oligonucleotide map of an envelop-defective deletion mutant (which lacks the major viral glycoprotein), mapped at a distance of 2800-5000 nucleotides from the poly(A) end of nd SR RNA. A cluster of two sarcoma-specific oligonucleotides, identified by their absence from an otherwise nearly identical oligonucleotide map of a transformation-defective deletion mutant, mapped at a distance of 1000-2000 nucleotides from the poly(A) end of nd SR RNA. The oligonucleotide maps of nd SR and of the two deletion mutants were the same from the poly(A) end up to 650 nucleotides and included one terminal oligonucleotid, termed C, which is found in all avian tumor viruses tested so far. A possible gene order consistent with our data suggests that sarcoma-specific nucleotide sequences map between envelope-specific nucleotide sequences and the poly(A) end of the RNA.
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PMID:Location of envelope-specific and sarcoma-specific oligonucleotides on RNA of Schmidt-Ruppin Rous sarcoma virus. 17 8

Full-length virion RNA and complementary mRNA's of vesicular stomatitis virus can be annealed to each other, digested with RNases, and then separated as five unique duplex RNA molecules on polyacrylamide slab gels. Similar RNA duplexes were detected whether mRNA or virion RNA was the radioactive component and whether the mRNA was synthesized in vitro or in vivo. The sharp banding pattern of these RNA molecules was dependent on treatment with RNase T2, suggesting that removal of poly(A) is necessary. Identification of the coding region contained in each RNA duplex was based on their previous identification as single-stranded mRNA on formamide-containing, polyacrylamide gels. Because the two smallest mRNA'S had not been previously separated, their identification was based on their in vitro transcriptional gene order. In the order of increasing mobilities on the slab gels, the RNA duplexes are identified as the hybrid of the region of the genome RNA hybridized to the complementary mRNA coding for the large protein, the glycoprotein, the nucleocapsid protein, the core-associated NS protein, and the matrix protein (L,G,N,NS, and M). Several lines of evidence support the presence of undegraded complete mRNA, excluding poly(A), in these RNA duplexes. Also, the two smallest mRNA's, separated by duplex formation, were denatured, and their individual oligonucleotide fingerprints were determined. From chemical length determinations, the molecular weights of the mRNA, minus poly(A), are 2.78 X 10(5) and 2.5 X 10(5), respectively, for the mRNA's of the NS and M proteins.
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PMID:RNA synthesis of vesicular stomatitis virus. VII. Complete separation of the mRNA's of vesicular stomatitis virus by duplex formation. 19 36

Two antigenic variants of visna virus were isolated sequentially from a single sheep inoculated with a plaque-purified strain of virus designated 1514. The genetically stable variants, LV1-1 and LV1-4, are of two classes: LV1-1 is partially neutralized by antibody to the inoculum strain 1514, while LV1-4 is not neutralized by antibody to 1514. The genetic mechanism responsible for generating the antigenic variants was investigated by comparing the chymotryptic and tryptic maps of the envelope glycoprotein gp135 and core polypeptides (p30, p16, p14), and by comparing the pattern of large oligonucleotides produced by digestion of the RNAs by T1 ribonuclease. We show that only the peptide maps of gp135 differ among strains, that the number of peptide fragments altered is small and that gp135 is the polypeptide that elicits neutralizing antibody. The maps of the RNAs are identical. We conclude that mutation in the glycoprotein gene rather than recombination is more probably responsible for antigenic variation, and speculate on the special aspects of visna virus replication relevant to this phenomenon.
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PMID:Antigenic variation in visna virus. 22 3

The bovine exocrine pancreatic cell produces a variety of enzymes and proenzymes for export. Biochemical studies by Greene L.J., C.H. Hirs, and G.E. Palade (J. Biol. Chem. 1963. 238:2054) have shown that the mass proportions of several of these proteins in resting pancreatic juice and zymogen granule fractions are identical. In this study we have used immunocytochemical techniques at the electron microscope level to determine whether regional differences exist in the bovine gland with regard to production of individual secretory proteins and whether specialization of product handling occurs at the subcellular level. The technique used is a modification of one previously reported (McLean, J.D., and S.J. Singer. 1970. Proc. Natl. Acad. Sci U.S.A. 69:1771) in which immunocytochemical reagents are applied to thin sections of bovine serum albumin-imbedded tissue and zymogen granule fractions. A double antibody technique was used in which the first step consisted of rabbit F(ab')2 antibovine secretory protein and the detection step consisted of sheep (F(ab')2 antirabbit F(ab')2 conjugated to ferritin. The results showed that all exocrine cells in the gland, and all zymogen granules and Golgi cisternae in each cell, were qualitatively alike with regard to their content of secretory proteins examined (trypsinogen, chymotrypsinogen A, carboxypeptidase A, RNase, and DNase). The data suggest that these secretory proteins are transported through the cisternae of the Golgi complex where they are intermixed before copackaging in zymogen granules; passage through the Golgi complex is apparently obligatory for these (and likely all) secretory proteins, and is independent of extent of glycosylation, e.g., trypsinogen, a nonglycoprotein vs. DNase, a glycoprotein.
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PMID:Immunocytochemical localization of secretory proteins in bovine pancreatic exocrine cells. 31

The normal level of serum or plasma poly C-avid ribonuclease activity is 1047 +/- 247 U/mL. Serum levels increase proportionately with elevations in serum creatinine, reaching levels of 9,500-35,000 in patients undergoing dialysis. The levels can be normalised by successful renal transplantation but not by dialysis. Purified human urinary ribonuclease, a glycoprotein enzyme similar to the serum ribonuclease, was capable of: 1) inhibiting the incorporation of 3H-thymidine into mitogen-stimulated lymphocytes; 2) inhibiting the proliferation and growth of bone marrow red cell colonies; and 3) adversely affecting the growth and viability of precursor fat cells.
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PMID:Ribonuclease activity in renal failure: evidence for toxicity. 34 Nov 43


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