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)

A single stained band containing approximately 5 micrograms of protein was cut out of a polyacrylamide gel and subjected to hydrolysis together with the gel. The hydrolysate was subsequently analyzed for its amino acid content by high-performance liquid chromatography and postlabeling with o-phthalaldehyde. Bovine serum albumin, ribonuclease B, ovalbumin, pepsin, and chymotrypsinogen A were analyzed by this method, and their amino acid compositions were found to be in good agreement with the reported values. By this method, it is possible to quantitate 16 amino acids: Asx, Thr, Ser, Glx, Pro, Cys, Gly, Ala, Val, Ile, Leu, Tyr, Phe, His, Lys, and Arg. Thioglycolic acid is effective protection against the decomposition of Tyr, Cys, and Met; however, the recovery of Met is inconsistent. This method might be very helpful for the amino acid analysis of proteins of multicomponent systems, especially, those which can be resolved only by polyacrylamide gel electrophoresis.
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PMID:Amino acid analysis by high-performance liquid chromatography of a single stained protein band from a polyacrylamide gel. 357 64

A protein was isolated from plasma of partially (70%) hepatectomized rats that, injected in mice, increases the uptake of [3H]thymidine by liver DNA by 200-300% over that by injected control saline. The purification procedure consists essentially of three chromatography steps, employing Sephadex G-75, DEAE-cellulose and hydroxyapatite. The hepatic promoter (HP) preparation shows a single band in SDS/polyacrylamide (15%)-gel electrophoresis (silver stained), with an Mr of 64 000; its activity is suppressed by trypsin or pepsin and is unaffected by deoxyribonuclease or ribonuclease. On injection into mice (150 ng/mouse), it increases the mitotic index of the liver. It shows organ-specificity, acting on liver but not on spleen, kidney, lung or brain. In primary liver cultures, it produces an increase in uptake of [3H]thymidine into DNA in the range 1-10 ng/ml. In this system in vitro, it increases the uptake of 22Na+ immediately after addition.
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PMID:Purification of a liver DNA-synthesis promoter from plasma of partially hepatectomized rats. 374 89

Phenol has been added to the Coomassie Brilliant Blue G-250 dye reagent used in the standard Bradford protein assay and its effect upon the reagent blank and assay response of fourteen proteins investigated. Phenol can enhance or impair colour yield depending upon its concentration and the amount and type of protein assayed. Four characteristic protein responses to increasing assay concentrations of phenol have been observed. These indicate a complex influence of phenol upon the protein assay. Dye reagent containing 0.5% phenol gave optimal colour yield with most of the proteins investigated and an improved assay response of ovalbumin, ribonuclease, lysozyme, insulin, pepsin and chymotrypsinogen-A relative to bovine albumin.
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PMID:Phenol addition to the Bradford dye binding assay improves sensitivity and gives a characteristic response with different proteins. 378 18

Cytological and cytochemical studies of green monkey kidney cells infected with SV40 virus indicated that the type of lesion produced was influenced by the multiplicity of infection and that the lesions appeared later and progressed more slowly when the inoculum was diluted. The earliest change consisted of enlargement of ribonucleoprotein-containing spherules in the nucleolus (nucleolini). This was followed by rarefaction, with or without condensation, of the chromatin and the appearance of one or more homogeneous masses of inclusion material containing DNA, RNA, and non-histone protein which eventually filled the nucleus. In some instances the chromatin appeared to be directly transformed into inclusion material. In the later stages of infection, the ribonucleoprotein of the nucleolini was no longer stainable and material resembling the nucleoprotein of the intranuclear inclusions was found in the nucleolar vacuoles and in the cytoplasm. The nucleic acids in the inclusions were stained by toluidine blue, toluidine blue-molybdate, the Feulgen stain, and by methyl green. The stainable material was extractable by nuclease digestion or by hot trichloroacetic acid. Green or yellowish green staining by acridine orange was apparently due to binding of dye by protein and not by nucleic acids since the staining reaction was not reduced by extraction of nucleic acids by hot trichloroacetic acid. Extraction with pepsin in combination with ribonuclease or deoxyribonuclease removed practically all the inclusions from the cells; consequently they could not be stained with acridine orange. The cytochemical studies suggest that the use of pepsin together with nuclease is not a meaningful technique.
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PMID:Cytological and cytochemical studies of green monkey kidney cells infected in vitro with simian virus 40. 428 71

Electron microscope examination of the adrenal cortex from three male human subjects revealed a special type of cell occurring in periendothelial spaces, in all adrenal cortex zones. It is a clear, spindle-shaped cell the principal cytoplasmic features of which are crystalline inclusions with a structure similar to that of the Reinke crystals of human testicular interstitial cells and an abundance of microfilaments. Enzymatic digestions with pronase, pepsin, and ribonuclease were performed, and no digestion of the crystals was obtained. The crystals had no peroxidase or acid phosphatase activities. This cell appears to be exclusive to human males and it may be related to adrenal androgen secretion.
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PMID:A new crystal-containing cell in human adrenal cortex. 434 48

The vitamin B(12)-binding property of Lactobacillus leichmannii ATCC 7830 has been studied. The organism could bind 0.52 mug of B(12) per mg of cells. With regard to the cellular site for B(12) accumulation, three-quarters of the B(12) bound to the cell was found in the crude cell wall fraction, and the remaining one-quarter was found in the particulate (ribosome) fraction. After receiving enzymatic treatments with ribonuclease, lipase, and trypsin, the wall fraction retained three-fifths of the initial B(12). The possibility of cross-contamination of the wall and particulate fractions was excluded by measuring the contents of ribonucleic acid and hexosamines in each fraction. The B(12)-binding activity of the wall was destroyed by pretreatment of the wall with pepsin, Pronase, or trypsin. However, once bound to the wall, the B(12) was not released by the same treatments. These facts suggest that B(12) is bound to a polypeptide in the wall on which these enzymes act and that, once bound, B(12) somehow inhibits the enzymatic actions as described earlier with L. delbrueckii no. 1. A B(12)-polypeptide complex was isolated by treatment with 0.2 n HCl from walls to which B(12) had been bound. The complex was then purified. The complex moves as a single band on polyacrylamide gel electrophoresis. Its molecular weight was estimated around 21,500 with microheterogeneity on a Sephadex G-75 column. The mode of B(12) binding was found to be similar to that of L. delbrueckii.
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PMID:Further studies on the binding of vitamin B 12 to the cell wall of a B 12 -requiring Lactobacillus. 455 Jun 59

The architecture of the nucleolus in Allium porum and Triticum vulgare meristematic cells has been investigated by means of digestions with various enzymes. After staining with azure B at pH4, plant nucleoli exhibit lighter regions which, under electron microscopy, correspond to the fibrillar zones characterizing these organelles. Evidence is presented indicating that these latter zones contain coarse convoluted filaments quite similar to the loops first demonstrated by La Cour (24) and which are assumed to originate from the nucleolar-organizing chromosomes. These coarse, 0.2micro wide filaments are remarkably resistant to the action of deoxyribonuclease, ribonuclease, pepsin, trypsin, or of various combinations of these enzymes and, moreover, they show insignificant incorporation of labeled thymidine even after long exposure to this DNA precursor. The clearing action of pepsin on different regions of the nucleolus lends support to the hypothesis that an amorphous material or matrix pervades the mass of this organelle. This effect is particularly striking within the particulate nucleolar zones themselves. Both ribonuclease and trypsin disorganize the RNP (ribonucleoprotein) nucleolar particles. The effect of the latter enzyme on the RNP particles is taken to indicate that they contain proteins particularly susceptible to trypsin which are essential for maintenance of their morphological integrity. Trypsin also interferes with azure B-staining of the nucleolar mass as a whole and, according to radioautographic data, extracts RNA throughout this organelle. Accordingly, the hypothesis is considered that RNA is complexed with proteins not only within the particulate nucleolar portions, as is already well known, but also in the fibrillar zones.
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PMID:The organization of the nucleolus in meristematic plant cells. A cytochemical study. 488 77

Fine structural aspects of human tissue culture cell nucleoli were studied by cytochemical and radioautographic methods. Ribonuclease and pepsin digestions were carried out on glutaraldehyde-fixed cells that, in some instances, were labeled with thymidine-(3)H prior to digestion. Double digestion by ribonuclease and pepsin revealed a fine fibrillar reticulum that appears to be the supportive structure of nucleolonemal threads. The nature of the reticulum remains to be determined. The question of whether it may represent a dispersed form of chromatin was raised. Structural findings suggested such an hypothesis but the results of radioautographic studies do not support it. The reticulum showed a striking absence of radioactive labeling following a 3 hr incorporation of thymidine-(3)H. Only few silver grains were observed occasionally in the fibrillar nucleolonema that may or may not be significant. The radioautographic results are believed to be inconclusive for the various reasons discussed. The possibility that the reticulum is composed of proteins has to be considered. It appears that basic proteins can resist pepsin digestion in aldehyde-fixed cells. Individual chromatin fibrils were found to be associated with the nucleolar reticulum. It is possible that these alone represent the dispersed genetically active chromatin of nucleoli.
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PMID:A cytochemical and radioautographic study of human tissue culture cell nucleoli. 491 12

Franklin, Richard M. (Institut de Recherches sur le Cancer, Villejuif, Seine, France), and Nicole Granboulan. Ultrastructure of Escherichia coli cells infected with bacteriophage R17. J. Bacteriol. 91:834-848. 1966-Ultrastructural changes in Escherichia coli cells infected with ribonucleic acid (RNA) bacteriophage R17 were studied under conditions of one-step growth. No morphological alterations were seen during the latent period. During the period of rapid viral synthesis, a fibrillar lesion surrounded by ribonucleoprotein particles was observed in a polar region. Late in infection, paracrystalline arrays of virions were found in over 90% of the cells. When protein synthesis was blocked by in over 90% of the cells. When protein synthesis was blocked by chloramphenicol at 20 min postinfection, allowing continued viral RNA synthesis without production of coat protein, a dense fibrillar area appeared in a paranuclear region. Cytochemical studies were done on cells embedded in hydroxypropyl methacrylate, a water-miscible embedding agent. The paracrystalline arrays of virions were digested after extensive treatment with either pepsin or ribonuclease. Shorter digestion with the pepsin resulted in better definition of the crystal regions. The fibrillar area found in chloramphenicol-treated cells was digested by ribonuclease but not by pepsin, and was also resistant to lead extraction. This region probably represents a pool of virus-specific RNA.
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PMID:Ultrastructure of Escherichia coli cells infected with bacteriophage R17. 532 73

The biological activity of Odontomyces viscosus, which has been reported to cause periodontal disease in hamsters, was examined. The microorganism was cultured anaerobically in Brain Heart Infusion broth, and the cells were harvested. The washed cells were injected intradermally into the abdomen of rabbits. After 72 hr, a well-defined, firm, raised nodule (about 1.0 by 1.5 cm) with an erythematous border was seen at the injection site. Suspensions of cell wall and cytoplasmic material were injected intradermally, and the lesions appeared only at the site of cell wall injection. The cell walls, which were then treated with trypsin, pepsin, and ribonuclease, again produced the characteristic lesion. These nodular dermal lesions persisted for a minimal time of 10 days. The enzymatically treated cell walls were then hydrolyzed with 1 n HCl, and such hydrolysis up to 1 hr failed to alter the toxic activity of the cell walls. Similar dermal nodular lesions were obtained by injection of enzymatically treated cell walls of strains of Staphylococcus aureus, Streptococcus groups B, C, E, F, K, Lactobacillus casei, and Actinomyces israelii. Treatment with hot and cold trichloroacetic acid solutions and proteolytic enzymes, or with formamide, yielded insoluble fractions which produced the characteristic nodular lesions. The size of the lesion resulting from injection of these fractions was proportional to the amount of the injected material. The active fraction, which does not appear susceptible to hydrolysis by lysozyme, is thought to be cell wall mucopeptide. Histological studies showed skin abscesses due to the toxic reaction; however, in addition to the acute inflammatory reaction, there was local eosinophilia.
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PMID:Toxic properties of the cell wall of gram-positive bacteria. 533


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