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)

Porcine rotaviral infectivity for continuous porcine kidney (PK-15) cells was enhanced by incorporation of pancreatic endopeptidases into the cell culture maintenance medium. Marked enhancement of infectivity was induced by trypsin, whereas elestase and alpha-chymotrypsin enhanced infectivity to a lesser extent. Bacterial protease also induced some enhancement of porcine rotaviral infectivity. A synergistic enhancement of porcine rotaviral infectivity was noticed with trypsin and alpha-chymotrypsin combined. Porcine rotaviral infectivity was not affected by incorporation of alpha-amylase, alkaline phosphatase, beta-galactosidase, carboxypeptidase-A, deoxyribonuclease, enterokinase, lipase, or ribonuclease into the maintenance medium.
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PMID:Porcine rotaviral infection of cell culture: effects of certain enzymes. 624 64

Purpura was grossly observable in albino mice 6 to 8 h after the intraperitoneal injection of sterile, deoxyribonuclease-treated, cell-free extracts prepared by sodium deoxycholate-induced lysis, sonic disruption, Parr bomb treatment, autolysis without sodium deoxycholate, or alternate freezing and thawing of washed suspensions of Streptococcus pneumoniae type I. Cell-free extracts obtained from sonically disrupted, heat-killed cells (100 degrees C for 20 min) did not contain purpurogenic activity. The reaction was maximal at approximately 24 h postinjection, started to fade slowly after 24 to 48 h, and usually was not grossly observable by 4 to 6 days postinjection. The purpura-producing principle (PPP) in the cell-free extract was purified by sequential ammonium sulfate precipitation, protamine sulfate precipitation, Sepharose 6B gel filtration, wheat germ lectin-Sepharose 6MB affinity chromatography, ribonuclease and trypsin treatment, and a second Sepharose 6B gel filtration step. The final preparation (i) contained glucosamine (5.6%), muramic acid (8.0%), neutral carbohydrate (12.8%), phosphate (8.0%), orcinol-reactive material (6.0%), and Lowry-reactive material (1.6%), and (ii) was free of detectable amounts of deoxyribonucleic acid, capsular polysaccharide, neuraminidase, cytolysin, and hyaluronidase. The isoelectric point and molecular size of the PPP were approximately pI 3.0 and several million daltons, respectively, and the activity remained in the supernatant fluid after centrifugation for 1 day at 105,000 x g. PPP activity was destroyed by incubation with egg white lysozyme and sodium metaperiodate but was resistant to trypsin, pronase, alpha-amylase, deoxyribonuclease, ribonuclease, alkaline phosphatase, pancreatic lipase, 7% trichloroacetic acid, 6 M urea, autoclaving (121 degrees C) for 30 min, and mild acid and alkali exposure. Our observations indicate that the PPP requires intact beta-1,4-glucosidic linkages for activity and support the working hypothesis that activity is associated with pneumococcal peptidoglycan solubilized by the bacterium's autolysin.
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PMID:Characterization of pneumococcal purpura-producing principle. 624 53

The growth of group A human, bovine, equine and porcine rotaviruses were enhanced by pretreatment of virus with pancreatin, trypsin, protease, alkaline phosphatase or pepsin and incorporation of these enzymes in maintenance medium. In contrast, alpha-amylase or lipase inhibited the growth of equine and porcine rotaviruses. The other enzymes, adenosine deaminase, lactase, lysozyme, ribonuclease or triose-phosphate isomerase gave little or no change in the growth of all four rotaviruses.
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PMID:Effect of enzymes on the growth of human and animal rotaviruses. 754 24

The effect of prolactin on the digestive potency of the acinar pancreas was examined in pituitary-grafted hyperprolactinemic mice, because our previous experiment showed that a marked proliferation of pancreatic acinar cells was induced by pituitary grafting in mice. To know whether the digestive function is modified, the tissue contents of pancreatic digestive enzymes, such as chymotrypsin, lipase alpha-amylase and ribonuclease, were measured in the hyperprolactinemic mice. Pituitary grafting significantly increased the contents of chymotrypsin and lipase in the pancreas on day 12 after the operation without affecting intake of food, when compared to those in the sham-operated controls. On day 30, however, the differences between pituitary-grafted and control mice were no more discernible. Thus, the digestive enzyme activities are easily modified soon after the increase of circulating prolactin level. This effect of prolactin on the function of the pancreas may be responsible for "homeorhetic" control of nutrients during lactation. In another set of experiments in adrenalectomized-castrated or castrated mice, pituitary grafting induced an increase in the weight of the pancreas. In addition, adrenalectomy in combination with castration did not alter the pancreatic contents of chymotrypsin and lipase but decreased the amylase content. These results taken together seem to indicate that the effect of prolactin on the exocrine pancreas is not mediated by gonadal and adrenal steroid hormones.
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PMID:Modification of pancreatic digestive function by pituitary grafting in mice. 765 48

We cloned a cDNA for a gibberellin-induced ribonuclease (RNase) expressed in barley (Hordeum vulgare) aleurone and the gene for a second barley RNase expressed in leaf tissue. The protein encoded by the cDNA is unique among RNases described to date in that it contains a novel 23-amino acid insert between the C2 and C3 conserved sequences. Expression of the recombinant protein in tobacco (Nicotiana tabacum) suspension-cultured protoplasts gave an active RNase of the expected size, confirming the enzymatic activity of the protein. Analyses of hormone regulation of expression of mRNA for the aleurone RNase revealed that, like the pattern for alpha-amylase, mRNA levels increased in the presence of gibberellic acid, and its antagonist abscisic acid prevented this effect. Quantitative studies at early times demonstrated that cycloheximide treatment of aleurone layers increased mRNA levels 4-fold, whereas a combination of gibberellin plus cycloheximide treatment was required to increase alpha-amylase mRNA levels to the same extent. These results are consistent with loss of repression as an initial effect of gibberellic acid on transcription of those genes, although the regulatory pathways for the two genes may differ.
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PMID:Cloning and characterization of a gibberellin-induced RNase expressed in barley aleurone cells. 1019 5

Among the physical factors which might influence micro-organisms one of the most potentially interesting is high vacuum. The effect of high vacuum is less studied as compared with other physical factors. It is impossible to achieve, under laboratory conditions, a vacuum of the order 10(-16) mm Hg which is probably characteristic of space. Earlier, the effect of high vacuum was studied on different bacteria, yeasts, molds and algae. It appeared that spores and fungal conidia were not killed by high vacuum. Later, the effect of high vacuum on physiological processes in micro-organisms was studied. The ability to oxidize glucose or ethanol was studied with Sarcina flava and Bacillus simplex cells after they were subjected for 72 hr to vacuum (10(-8) to 10(-9) mm Hg). The oxidation rate was followed polarographically. The oxidative ability of S. flava cells diminished [correction of dimished] after their subjection to vacuum, while B. simplex spores were unchanged in that respect. The following crystalline enzymes were subjected for 72 hr to the same vacuum: alpha-amylase, catalase, ribonuclease, trypsine and urease. Then the activity of the above enzymes was tested on corresponding substrates. Not a single enzyme was totally inactivated. About 50% of activity was lost with alpha-amylase; 25--35% of activity with catalase, ribonuclease and urease. Trypsine retained its total activity. Thus, high vacuum cannot be listed among factors rapidly inactivating enzymes of micro-organisms.
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PMID:The effect of high vacuum on oxidative reactions in bacteria and the activity of certain enzymes. 1266 21

1. Extracellular ribonuclease is produced linearly for at least 3hr. by washed post-logarithmic-phase cells of Bacillus subtilis suspended in a medium containing maltose (1%) and casein hydrolysate (0.5%). 2. Low concentrations of actinomycin D (less than 2mug./ml.) stimulate ribonuclease formation, the maximum effect being observed with a concentration of 1mug./ml. Concentrations greater than 2mug./ml. are inhibitory. There is no parallel stimulation of alpha-amylase formed under the same conditions, and [(14)C]uracil incorporation into a perchloric acid-insoluble form is inhibited. 3. The actinomycin D-induced stimulation is not due to the presence of an activator, nor is the inhibition due to the release of an inhibitor by the cells. The effect is on the amount of ribonuclease produced in the medium. 4. Extracellular ribonuclease formation is partially inhibited by anaerobiosis, 2,4-dinitrophenol, sodium azide and by chloramphenicol and puromycin. 5. High concentrations of antibiotic do not completely inhibit ribonuclease formation, but a basal amount of enzyme representing 20min. synthesis in an uninhibited system is always produced. This ;antibiotic-insensitive' enzyme could possibly represent preformed enzyme ;in the pipe-line' en route to secretion. 6. The stimulated appearance of ribonuclease in the presence of 1mug. of actinomycin D/ml. is shown to be dependent on enzyme synthesis. The mechanism of this effect is discussed.
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PMID:EXTRACELLULAR RIBONUCLEASE FORMATION IN BACILLUS SUBTILIS AND ITS STIMULATION BY ACTINOMYCIN D. 1434 5

Towards a goal of detecting scaled-up DNA adducts as altered deoxynucleotides by mass spectrometry, we have set up a practical and general method for isolating DNA-derived deoxyribonucleoside-5'-monophosphates devoid of ribonucleotides starting with a 1 g sample of mammalian tissue. The method is practical because costs have been minimized, and it is general because it can be applied to a more difficult sample such as mouse skin or non-fresh calf liver. The procedure, consisting of a series of steps that were largely gleaned and tuned from prior literature, proceeds as follows: (1) homogenize the tissue in sodium dodecyl sulfate; (2) digest with ribonuclease A, ribonuclease TI, alpha-amylase and proteinase K; (3) partition between water and phenol; (4) precipitate the DNA with ethanol followed by redissolving and dialysis; and (5) digest with nuclease P1 and phosphodiesterase I followed by ultrafiltration and boric acid gel chromatography. The yellow to brown color of DNA from difficult tissues only persisted up to the ultrafiltration step. Apparently this DNA was contaminated with iron-containing proteins. Residual ribonucleotides were not observable (<0.1%) by HPLC in the final sample. Without boric acid gel chromatography, residual contamination by ribonucleotides was about 1% even when the DNA was purified before digestion by phenol partitioning followed by use of a Genomic Tip kit from Qiagen.
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PMID:Phenolic extraction of DNA from mammalian tissues and conversion to deoxyribonucleoside-5'-monophosphates devoid of ribonucleotides. 1554 80

Gibberellic acid enhances the synthesis of alpha-amylase in isolated aleurone layers of barley-seeds (Hordeum vulgare var. Himalaya). In the presence of 20 mm calcium chloride the amount of enzyme obtained from isolated aleurone layers is quantitatively comparable to that of the half-seeds used in earlier studies. After a lag period of 6 to 8 hours enzyme is produced at a linear rate. Gibberellic acid does not merely trigger alpha-amylase synthesis, but it is continuously required during the period of enzyme formation. Enzyme synthesis is inhibited by inhibitors of protein and RNA synthesis. Small amounts of actinomycin D differentially inhibit enzyme release and enzyme synthesis suggesting 2 distinct processes. Gibberellic acid similarly enhances the formation of ribonuclease which increases linearly over a 48 hour period. During the first 24 hours the enzyme is retained by the aleurone cells and this is followed by a rapid release of ribonuclease during the next 24 hour period. The capacity to release the enzyme is generated between 20 and 28 hours after the addition of the hormone. Ribonuclease formation is inhibited by inhibitors of protein and RNA synthesis. These inhibitors also prevent the formation of the release mechanism if added at the appropriate moment.
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PMID:Gibberellic Acid-enhanced synthesis and release of alpha-amylase and ribonuclease by isolated barley and aleurone layers. 1665 17

Gibberellic acid (GA) enhances the synthesis of alpha-amylase and ribonuclease in isolated aleurone layers and this process is inhibited by abscisin. Removal of gibberellic acid in mid-course of alpha-amylase production results in a slowing down of alpha-amylase synthesis, suggesting a continued requirement of GA for enzyme synthesis. This is paralleled by a continuous requirement for RNA synthesis. Addition of 6-methylpurine or 8-azaguanine in mid-course results in an inhibition of alpha-amylase synthesis within 3 to 4 hours. However, actinomycin D added in mid-course is almost without effect. This is not due to its failure to enter the cells, because it does inhibit (14)C-uridine incorporation at this stage. Addition of abscisin to aleurone layers which are synthesizing alpha-amylase results in an inhibition of this synthesis within 2 to 3 hours. Cycloheximide on the other hand inhibits enzyme synthesis immediately upon its addition. These data are consistent with the hypothesis that the expression of the GA effect requires the synthesis of enzyme-specific RNA molecules. The similarity in the kinetics of inhibition between abscisin on the one hand and 8-azaguanine or 6-methylpurine on the other suggests that abscisin may exert its action by inhibiting the synthesis of these enzyme-specific RNA molecules or by preventing their incorporation into an active enzyme-synthesising unit.
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PMID:Hormonal control of enzyme synthesis: on the mode of action of gibberellic Acid and abscisin in aleurone layers of barley. 1665 90


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