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

At 2 degrees and 30 degrees C, enteroviruses are more stable on the acid than on the alkaline side of neutrality. In the range from pH 3 to 9, temperature is so influential that the fastest inactivation rate at 2 degrees C is slower than the slowest inactivation rate at 30 degrees C. Specific ions or salts also affect the rate of inactivation of enteroviruses. NaCl and other chloride salts enhance the inactivation of poliovirus at pH 3. NaCl is considerably less effective against poliovirus in the range of pH 4.5 to 7.0 than at pH less than 4.5. Loss of RNA infectivity of the virus particle proceeds as rapidly as the loss of infectivity of the particle itself, except at pH 3 in the presence of MgCl2. Inactivation results in alterations to the physical integrity of enteroviruses. At pH 5 and 7, RNA hydrolysis of poliovirus particles occurs; and at pH3, 5,6, and 7 the nucleic acid becomes susceptible to ribonuclease. Only virus particles inactivated at pH 3 show a sensitivity to chymotrypsin. The hemagglutinins of echovirus type 7 are destroyed during inactivation at pH 3,4,5, and 6; but at pH 6 this alteration precedes the loss of infectivity. The pH of the suspension is a primary determinant of the mechanism of virus destruction and possibly of the loss of infectivity at these temperatures.
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PMID:Effect of acid pH, salts, and temperature on the infectivity and physical integrity of enteroviruses. 1 66

A proteolytic enzyme mixture, Orenzyme-Forte, containing trypsin, chymotrypsin, and ribonuclease was used to treat experimentally induced pulpitis in the teeth of three monkeys. Assessment by means of the criteria of Stanley showed that the enzyme mixture induced better healing than a zinc oxide--eugenol dressing. When the two were used simultaneously, a synergistic effect was seen. We suggest that this enzyme mixture may be useful in clinical practice in the treatment of pulpitis.
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PMID:The effect of a proteolytic enzyem mixture (Orenzyme-Forte) on experimentally induced pulpitis. 40 76

Though DNase does not contain any cysteine residues, incubation of the enzyme with 2-nitro-5-thiocyanobenzoic acid in the presence of Ca2+ at pH values above 7.5 results in an irreversible inactivation of the enzyme. The inactivation also occurs when Ca2+ is replaced by Mg2+, but not in their absence. Amino acid analyses after acid hydrolyses of the completely inactivated ant the native enzymes show no significant differences in composition, including tryptophan and half-cystine residues. However, sodium dodecyl sulfate gel electrophoresis indicates enzyme cleavage by the treatment with 2-nitro-5-thiocyanobenzoic acid. This reagent does not inactivate chymotrypsin and lysozyme, and under conditions where bovine DNase is inactivated, does not inactivate other nucleases such as ribonuclease, snake venom phosphodiesterase, and spleen acid DNase. However, it inactivates malt DNase and can, therefore, be considered a specific inhibitor of DNase I. The inactivation kinetics is pseudo-first order, resembling Michaelis-Menten, with an affinity constant of 16.7 mM. It is the cyano group, not the thionitrobenzoic acid of 2-nitro-5-thiocyanobenzoic acid that reacts to form cyano-DNase.
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PMID:Inactivation of bovine pancreatic DNase by 2-nitro-5-thiocyanobenzoic acid. I. A novel inhibitor for DNase I. 48 54

Antigen-treated lymphocytes from immune hamsters specifically protected not only macrophages, but also cultured fibroblasts and kidney cells infected with Toxoplasma gondii or Besnoitia jellisoni. Macrophages were not necessary for the protection of fibroblasts and kidney cells. A mediator that inhibited the intracellular proliferation of these microbes was obtained from immune lymphocytes in contact with specific antigen. Again, macrophages were not necessary for the elaboration of this mediator or its activity in kidney cells or fibroblasts. The mediator was microbe and host specific, had a molecular weight between 4,000 and 5,000, was resistant to heating at 56 degrees C for 30 min, and was sensitive to chymotrypsin, but resistant to ribonuclease and deoxyribonuclease. A single injection of Besnoitia mediator afforded better protection to hamsters infected with Besnoitia than did antibody. Whereas antibody lysed extracellular organisms, the microbe-specific mediators conferred immunity not only on macrophages, but also on other cells of the body, apparently the first such demonstration.
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PMID:Mediation of immunity to intracellular infection (Toxoplasma and Besnoitia) within somatic cells. 64 Jul 41

When pancreatic DNase I is used as a specific biochemical reagent in the preparation of nuclear ribonucleic acids or nuclear proteins, freedom from contaminating ribonucleases or proteases is an important property of the enzyme preparation. A simple one-step procedure has been developed to effect complete removal of trypsin, chymotrypsin, and chymotrypsinogen by a combination of affinity chromatography and salting-out adsorption on lima bean protease inhibitor coupled to Sepharose (a column (0.9 X 60 cm) operated in series with a regeneratable 1-ml bed). Commercial preparations of DNase (about 10 mg) give a quantitative yield of the enzyme that is protease-free as evidenced by full stability for more than 10 days at pH 8 and 37 degrees C even in the absence of the protecting action of Ca2+. Removal of the last traces of RNase has been accomplished by affinity chromatography on a column (0.4 X 72 cm) of 5'-(4-aminophenyl-phosphoryl)-uridine 2'(3')-phosphate-Sepharose; the product is a highly active DNase that gives no detectable hydrolysis of RNA by assay on radioactive substrates.
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PMID:Preparation of protease-free and ribonuclease-free pancreatic deoxyribonuclease. 70 Dec 44

Tilorone hydrochloride, an interferon inducer in small laboratory animals, was demonstrated to elicit formation of macrophage migration affecting and microbial growth inhibitory cytokines after peroral drug administration to mice. Serum kinetics of the migration inhibitory cytokine resembled those of interferon, exhibiting a peak after about 24 h, whereas the bactericidal cytokine showed a steady increase up to 48 h after drug treatment. Both the factors were found to have molecular weights of 10,000--30,000 daltons as determined by Sephadex G-200 chromatography, to be stable at pH 2 and at 56 degrees C for 30 min, sensitive to chymotrypsin and resistant to RNase digestion. The migration enhancing serum activity could not finally be characterized so far. The physicochemical data are discussed in comparison to those of lymphocyte-derived cytokines. It is suggested that cytokine production may be, at least partially, responsible for the immunological effects of tilorone and possibly contribute to its antiviral action.
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PMID:Induction of cytokines by tilorone hydrochloride. 71 85

Modification of hen egg-white lysozyme by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide in presence of 4-phenylbutylamine yielded derivatives, which contained 0.6--0.7 modified residues and retained about 60% of the original activity. Kinetic studies revealed that the modified-lysozyme increases approx. 20-fold the kcat of hydrolysis of SucGly2Phe-4-nitroanilide by alphachymotrypsin, without changing the Km. The apparent dissociation constant of phenylbutylamine-modified lysozyme . chymotrypsin complex was found to be 0.03 mM and independent of substrate concentration. The accelerating effect of the modified lysozyme was also observed with other p-nitroanilide substrates of alpha-chymotrypsin. However, the hydrolysis of other substrates, acylation by active site titrant or inhibition by irreversible or competitive inhibitors were uneffected. The enhancing effect of the modified lysozyme seems to be very specific since other chymotrypsin-like enzymes, or serine proteinases except delta-chymotrypsin, were not influenced and phenylbutylamine derivatives of alpha-lactalbumin or ribonuclease were lacking any enhancing effect. Smaller, but significant enhancing effect was found also in lysozyme substituted by benzylamine, beta-phenylethylamine and tryptamine and in inactive derivatives of lysozyme substituted by phenylbutylamine. Competitive inhibitors of lysozyme such as N-acetyl-D-glucose amine oligomers, (GlcNAc)2 and (GlcNAc)3 abolished partially the accelerating effect of phenylbutylamine-modified lysozyme, indicating that the substituted group is located in the vicinity of the binding site.
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PMID:Enhancement of alpha-chymotrypsin-catalyzed hydrolysis of specific p-nitroanilide substrates by 4-phenylbutylamine derivative of hen egg-white lysozyme. 71 65

Exposure of mycobacterial growth inhibitory factor (MycoIF) to trypsin, chymotrypsin, or neuraminidase decrease its ability to produce intracellular inhibition of mycobacterial growth within macrophages, suggesting that MycoIF was a glycoprotein. MycoIF was unaffected by deoxyribonuclease or ribonuclease. Supernatant fluids from antigenically stimulated H37Ra-immunized mouse spleen cells exposed to puromycin were unable to produce significant intracellular inhibition. This indicated that the presence of MycoIF activity in supernatant fluids required protein synthesis. The filtration of MycoIF-containing supernatant fluids on Sephadex G-150 demonstrated that significant MycoIF activity appeared only in those fractions which eluted on the downward side of the serum albumin peak. Based on protein standards filtered through the Sephadex gel, the molecular weight of MycoIF was calculated to be between 20,000 and 35,000. These calculations assumed that MycoIF is a globular protein. Attempts to purify MycoIF by anion exchange chromatography (diethylaminoethylcellulose) was not successful.
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PMID:Molecular weight and other characteristics of mycobacterial growth inhibitory factor produced by spleen cells obtained from mice immunized with viable attenuated mycobacterial cells. 81 60

The experiments reported here indicate that, when exposed to insulin, viable lymphocytes rapidly released into the incubation medium a factor capable of increasing the dextran-induced anaphylactoid reaction, but having no effect on the inflammatory response evoked by 5-HT. This pro-inflammatory factor was shown to be elaborated by cell suspensions derived from lymph nodes of rats, rabbits, pigs or calves as well as from human tonsils. Thymus cells showed no such activity. The pro-inflammatory factor was termed as anaphylactoid-inflammation-promoting factor (AIPF). Its production depended upon the dose of insulin, and the time of exposure. AIPF was found to have an elution pattern in Sephadex G-100 gels similar to that of BSA (67,000 daltons). The activity was abolished by heat or incubation with DNase or a-chymotrypsin, but was not influenced by RNase. AIPF by itself did not induce increased vascular permeability, and proved to be distinct from the permeability factors present in the lysate of lymph node cells.
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PMID:Anaphylactoid-inflammation-promoting factor. An insulin-induced factor derived from non-sensitized lymphocytes increases anaphylactoid inflammation in rats. 115 Mar 30


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