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:3.1.27.5 (RNase)
17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

tolA mutants of Escherichia coli K-12 release periplasmic proteins into the extracellular medium; they are sensitive to growth inhibitors such as cholic acid and tolerant to group A colicins and filamentous bacteriophage. Suppressor mutants of the tolA-876 allele were isolated by selecting for cholic acid resistant clones that did not release periplasmic ribonuclease I. One class of tolA suppressor strains carried mutations in the staA gene (for suppressor of tolA) located a 41 min. tolA-876 staA strains partially recovered a wild-type phenotype: they exported alkaline phosphatase and beta-lactamase into the periplasm and only released very low amounts of periplasmic proteins; moreover, they were sensitive to E1 and A colicins and more resistant than tolA-876 staA+ strains to various growth inhibitors. Furthermore, tolA-876 staA-2 and tolA+staA-2 mutants were 10- to 2700-times more resistant than staA+ strains to bacteriophages TuIa, TuIb and T4, and TuII whose receptors are major outer membrane proteins OmpF, OmpC and OmpA, respectively. SDS-PAGE analysis suggested that cell envelopes of staA or staA+ strains contained similar amounts of these proteins but characterization of strains carrying ompF (or C or A)-phoA gene fusions showed that mutation stA-2 reduced ompF gene expression by a factor of two. Analysis of double mutants strains carrying mutation staA-2 and a tolA, tolB, excC or excD periplasmic-leaky mutation showed that staA suppression was allele specific which suggested that proteins TolA and StaA might directly interact.
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PMID:Isolation and characterization of extragenic suppressor mutants of the tolA-876 periplasmic-leaky allele in Escherichia coli K-12. 204 Apr 38

Preparations of tobacco etch virus (TEV) RNA which were purified by sucrose gradient centrifugation, digested with RNase, and analyzed by SDS-polyacrylamide gel electrophoresis contained proteins of 49, 32, and 24 kDa. The 49- and 24-kDa proteins reacted with polyclonal antiserum to the TEV 49-kDa proteinase while the 32-kDa protein reacted with anti-TEV serum. Further purification of the RNA by centrifugation through CsCl removed the coat protein (32 kDa), but not the 49- and 24-kDa proteins. The 49- and 24-kDa proteins did not migrate into a polyacrylamdie gel when the RNA was not digested with RNase. These results indicate that the VPg of TEV is either the 49-kDa proteinase or the 24 kDa that represents the amino-terminal half thereof.
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PMID:The VPg of tobacco etch virus RNA is the 49-kDa proteinase or the N-terminal 24-kDa part of the proteinase. 220 47

Apolipoprotein (apo) B-48 mRNA is the product of RNA editing which consists of a C----U conversion changing a CAA codon encoding Gln-2153 in apoB-100 mRNA to a UAA stop codon in apoB-48 mRNA. In the adult rat, RNA editing occurs both in the small intestine and the liver. We have studied the ability of rat liver nuclear extracts to bind to synthetic apoB mRNA segments spanning the editing site. Using an RNA gel mobility shift assay, we found the sequence-specific binding of a protein(s) to a 65-nucleotide apoB-100 mRNA. UV crosslinking followed by T1 ribonuclease digestion and SDS-polyacrylamide gel electrophoresis demonstrated the formation of a 40 kDa protein-RNA complex when 32P-labeled apoB-100 mRNA was incubated with a rat liver nuclear extract but not with HeLa nuclear extract. Binding was specific for the sense strand of apoB mRNA, and was not demonstrated with single-stranded apoB DNA, or antisense apoB RNA. The complex also failed to form if SDS was present during the UV light exposure. Binding experiments using synthetic apoB mRNAs indicate that the 40 kDa protein would also bind to apoB-48 mRNA but not apoA-I, apoA-IV, apoC-II or apoE mRNA. Experiments using deletion mutants of apoB-100 mRNA indicate efficient binding of wildtype 65-nucleotide (W65), 40-nucleotide (W40) and 26-nucleotide (W26) apoB-100 mRNA segments, but not 10-nucleotide (or smaller) segments of apoB-100 mRNA to the 40 kDa protein. In contrast, two other regions of apoB-100 mRNA, B-5' (bases 1128-3003) and B-3' (bases 11310-11390), failed to bind to the protein. The 40 kDa sequence-specific binding protein in rat liver nuclear extract may play a role in apoB-100 mRNA editing.
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PMID:A 40 kilodalton rat liver nuclear protein binds specifically to apolipoprotein B mRNA around the RNA editing site. 221 73

Two ribonucleases (RNases), one active against RNA as well as poly(C) and the other more markedly against poly(C), were isolated from human erythrocytes by acetone fractionation in the presence of 0.25 M H2SO4, followed by a series of column chromatographies. The purified enzymes appeared homogeneous as judged by sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE), and were tentatively designated RNase HE-1 and RNase HE-2. The content of RNase HE-1 in erythrocytes was much higher than that of RNase HE-2. The molecular mass of RNase HE-1 was determined to be 18,000 and 16,000 Da, and that of RNase He-2 39,000 and 31,000 Da, by SDS-PAGE and gel filtration, respectively. The catalytic properties and structural features of RNase HE-1 including the amino acid composition and N-terminal amino acid sequence indicated that its protein moiety is strictly related to a nonsecretory RNase purified from human urine (Yasuda et al., 1988, Biochim. Biophys. Acta 965, 185-195). In particular, the N-terminal amino acid sequence up to the 32nd residue was identical with that of urine nonsecretory RNase reported recently (Beintema et al., 1988, Biochemistry 27, 4530-4538). Furthermore, RNase HE-1 was immunologically indistinguishable from urine nonsecretory RNase, but clearly differed from urine secretory RNase. On the other hand, erythrocyte RNase HE-2 was enzymologically and immunologically similar to urine secretory RNase.
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PMID:Purification and characterization of two ribonucleases from human erythrocytes: immunological and enzymological comparison with ribonucleases from human urine. 233 45

A ribonuclease has been isolated from human spleen (RNase HS) by means of acid extraction, ammonium sulphate fractionation, successive column chromatographies on CM-cellulose, heparin-actigel, and poly(G)-agarose, and double gel-filtration on Sephadex G-75. The purified preparation was homogeneous as judged by SDS/PAGE. RNase HS was found to be a glycoprotein, containing three fucose, one mannose and five glucosamine residues/molecule, with a molecular mass of 17 kDa as determined by both SDS/PAGE and gel filtration. The catalytic properties and structural features, including its amino acid composition and the amino acid sequence of the N-terminal 35 residues, indicated that the enzyme was strictly related to nonsecretory RNase isolated from human urine and liver. In particular, the amino acid sequence of the N-terminal was identical with that of urine nonsecretory RNase and eosinophil-derived neurotoxin. Furthermore, analyses using three different antibodies specific to RNase HS, urine nonsecretory RNase and urine secretory RNase, indicated that RNase HS was not immunologically distinguishable from urine nonsecretory RNase, but clearly so from urine secretory RNase. However, the carbohydrate compositions of RNase HS and urine nonsecretory RNase were found to differ. It therefore remains to be resolved whether or not the tissue of origin of nonsecretory RNase in urine is the spleen.
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PMID:Purification and characterization of a ribonuclease from human spleen. Immunological and enzymological comparison with nonsecretory ribonuclease from human urine. 238 98

A reproducible and economical procedure for obtaining a large and quantitative yield of highly purified covalently closed circular plasmid DNA is described. The procedure departs in several ways from more commonly used methods. These are a) avoidance of the use of CsCl, ethidium bromide and ultracentrifuge, b) enrichment of the plasmid DNA by selective denaturation of chromosomal DNA with an alkaline-SDS solution, c) enrichment of covalently closed circular plasmid DNA by extraction with acid-phenol, and d) removal of small degraded RNA fragments by molecular sieve chromatography after digestion with RNase A. The plasmid DNA prepared by this new procedure is free of contaminants and has been used for DNA sequencing, in vitro transcription, transformation and in vitro mutagenesis.
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PMID:An economical large scale procedure to purify E. coli amplifiable plasmids for DNA sequencing, in vitro transcription and in vitro mutagenesis. 241 88

Intravenous infusion of synthetic secretin for periods up to 24 h in conscious rats was combined with in-vitro amino acid incorporation in isolated pancreatic lobules and high-resolution separation of individual enzyme proteins by two-dimensional isoelectric focusing and SDS gel electrophoresis. With this method persistent changes in the biosynthesis of ten enzyme and isoenzyme proteins can be studied as a result of prolonged secretin stimulation. Three major patterns of response were observed: progressive increases in the synthetic rates were found in six out of ten enzyme proteins with most pronounced changes in the synthetic rates of lipase (4.10-fold increase), two forms of proelastase (2.80-fold increase, respectively), the two acidic forms of trypsinogen and chymotrypsinogen (2.60- and 2.40-fold increase, respectively), and of ribonuclease (2.30-fold increase). Only moderate changes (1.30- to 1.90-fold increase) occurred in the synthetic rates of four isoenzymatic forms of procarboxypeptidase and the basic forms of chymotrypsinogen and trypsinogen, respectively. No absolute change in the rate of synthesis was observed in both forms of amylase. These data obtained after secretin stimulation differ significantly from previous results after caerulein stimulation, but it is not clear so far whether this is due to differential effects of the two second messengers released by each of the hormones on the level of transcription or translation.
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PMID:In-vivo stimulation of rat pancreatic acinar cells by infusion of secretin. II. Changes in individual rates of enzyme and isoenzyme biosynthesis. 241 53

An antigen recognized by monoclonal antibody specific for Bacteroides gingivalis was purified in the presence of 0.5% (wt/vol) beta-octyl-glucoside by immunoadsorbent column chromatography. The purified antigen was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining, and the pattern of SDS-PAGE agreed with that of immunoblotting. The molecule exhibited an apparent molecular weight of about 62,000 by SDS-PAGE. The antigen was sensitive to trypsin, Staphylococcus aureus V8 protease, DNase I and II, and heating, but insensitive to RNase and neuraminidase. By the enzyme-linked immunosorbent assay method, the purified antigen was not cross-reactive with rat polyclonal antibodies to each of several black-pigmented Bacteroides species, Fusobacterium nucleatum, Eikenella corrodens, and Actinobacillus actinomycetemcomitans. These results indicate that the purified antigen is specific for B. gingivalis. Humoral antibody titers in adult periodontal patients against the specific antigen were measured by the enzyme-linked immunosorbent assay. Serum immunoglobulin G antibody titers against the specific antigen in adult periodontal patients correlated significantly with the severity of periodontal disease. However, such significant correlation was not observed with serum immunoglobulin M antibody titers.
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PMID:Humoral antibody response against Bacteroides gingivalis-specific antigen recognized by monoclonal antibody in adult periodontal patients. 242

B lymphocytes from a patient with systemic lupus erythematosus (SLE) and several circulating autoantibodies (including antinucleolar antibodies) were immortalized by fusion with a hypoxanthine/guanine phosphoribosyl transferase (HGPRT)-deficient human B cell line. Multiple human monoclonal antibodies (mAb) were obtained which, in solid-phase enzyme immunoassay, were reactive with DNA. One mAb was of special interest because it reacted strongly with both single-stranded DNA and an extractable nuclear antigen found in rabbit thymus extract (RTE). In an immunofluorescent assay using fixed human cells, the latter mAb also bound predominantly to cell nucleoli. A combination of enzyme digestion and metabolic inhibitor studies of the target cells in this immunofluorescent assay suggested that the antigen(s) bound by the mAb was an RNA-associated protein or a ribonucleoprotein that is distinct from intact RNA polymerase I and not associated with the transcriptional units of the nucleolus. In other experiments, using fractions of RTE isolated by ion-exchange chromatography, the antigens bound by the mAb were shown to be highly negatively charged molecules. Immunoprecipitation and SDS-PAGE analyses of labeled cell extracts bound by the mAb revealed a doublet of 17 and 18 kD. Since the original patient's serum autoantibodies also bound to both an RNase-sensitive, acidic, extractable nuclear antigen and to nucleoli, and immunoprecipitated proteins of similar molecular masses in SDS-PAGE, it appears that the described mAb is a product of an immortalized autoantibody-producing B cell clone from the SLE patient's peripheral blood. This mAb probably defines a novel RNA-associated autoantigen residing predominantly in the nucleolus or, less likely, a variant of either RNA polymerase I or the ribosomal autoantigens (P proteins).
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PMID:Description and partial characterization of a nucleolar RNA-associated autoantigen defined by a human monoclonal antibody. 243 34

The glucocorticoid receptor from rat liver cytosol prepared in 2 ml buffer/g tissue sedimented at approximately 10 S in low salt density gradient centrifugation without molybdate. When the receptor was heated at 25 degrees C, both approximately 10 S and approximately 7 S forms were seen in low salt gradient. The approximately 10 S form was not capable of binding to DNA-cellulose and was stabilized by sodium molybdate, namely it corresponded to untransformed receptor. The approximately 7 S form was capable of binding to DNA-cellulose and regarded as transformed receptor. On the other hand, partially-purified transformed receptor labeled with [3H]dexamethasone-21-mesylate sedimented at approximately 5 S, which migrated as a approximately 94 kDa species in SDS-polyacrylamide gel electrophoresis. The reconstitution analysis of this partially-purified approximately 5 S receptor and liver cytosol, showed the shift to approximately 7 S form. RNase A or T1 converted approximately 7 S transformed form into approximately 5 S but it did not affect approximately 10 S untransformed form. 5-20 mM sodium molybdate also shifted approximately 7 S to approximately 5 S. These results indicate that the approximately 7 S transformed form of the glucocorticoid receptor observed in low salt conditions might be an oligomer, probably including both approximately 5 S steroid-binding component and RNA/ribonucleoprotein, and that molybdate dissociates these interactions in a specific manner.
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PMID:Sodium molybdate converts the RNA-associated transformed, oligomeric form of the glucocorticoid receptor into the transformed, monomeric form. 244 Nov 43


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