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:3.1.4.1 (phosphodiesterase)
18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A DNA endonuclease has been purified from eggs of Asterias forbesi by a simple four-step-purification procedure. The purified enzyme is at least 96% pure and is free of phosphatase, phosphodiesterase, and RNase. It has a pH optimum of 6.5 and does not require divalent cations. The enzyme produces 3'-phosphoryl and 5'-hydroxyl end groups. The products of exhaustive hydrolysis can be grouped in two fractions. The first fraction, 40%, contains a small amount of mononucleotides and di-, tri-, tetra-, penta-, and hexanucleo-tides. The second fraction, 60%, contains oligonucleotides larger than hexanucleotides.
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PMID:Purification and properties of a 3'-phosphoryl former endodeoxyribonuclease from eggs of Asterias forbesi. 1 46

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

The DNAase in human urine was purified about 30-fold with a recovery of 28%. This involved DEAE-cellulose and phosphocellulose chromatography steps and gel filtration on Sephadex G-75. The enzyme required divalent cations such as Co2+, Mg2+, Mn2+ and Zn2+ for activity, but Ca2+, Cu2+ and Fe2+ were ineffective. EDTA and G-actin inhibited the reaction. The maximum activity was observed at pH 5.5 in acetate buffer plus Co2+ or Mg2+ and Ca2+. It had a molecular weight of approximately 38 000, estimated by gel filtration on Sephadex G-75 and isoelectric point of around pH 3.9. The enzyme is an endonuclease which hydrolyzes native, double-stranded DNA about 3 to 4 times faster than thermally denatured DNA to produce 5'-phosphoryl- and 3'-hydroxyl-terminated oligonucleotides. The final preparation was free of non-specific acid and alkaline phosphatases, phosphodiesterase and ribonuclease activities.
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PMID:Purification and properties of deoxyribonuclease from human urine. 2 31

By sequential acid treatment, gel filtration and KM-cellulose sorption a 18--20-fold purified preparation of ribonuclease with a yield of 50--60% was obtained from the culture liquid filtrate of Actinomyces rimosus 994. The preparation had a high specific activity of 450,000--600,000 units/mg protein, contained 85--98% protein, insignificant amounts of carbohydrates and hydroxytetracycline, and no quantities of DNase, phosphomonoesterases, phosphodiesterase or proteases. In RNA degradation (preparation of the total yeast RNA of the Sigma Co.) optimal results were obtained at 50 degrees C and pH 7.0--7.2 in phosphate buffer and 7.6--8.0 IN Tris-HCl buffer. The preparation was stable at high temperatures (80--100 degrees) in the wide pH range and during storage in the lyophilized form and in buffer solutions. RNase effect was inhibited by zinc, copper, iron and cobalt cations and activated by beta-mercaptoethanol, citrate and EDTA. Protamine sulphate and urea in low concentrations (0.01% and 1--4 M, respectively) accelerated and in high concentrations (1% and 8 M, respectively) terminated the enzyme reaction. With respect to many properties RNase from Act. rimosus 994 was similar to extracellular RNases, produced by other actinomycetes and fungi.
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PMID:[Preparation of extracellular ribonuclease form Actinomyces rimosus 994]. 3 16

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

The paper describes a method for isolating alkaline ribonuclease from the culture liquid Bacillus subtilis KP 349 which involved: submerged cultivation of the producer on complex and synthetic nutrient media with optimized RNase activity, acid treatment of the total culture liquid, and filtration through perlite. Further treatment may include either spray drying of the culture liquid filtrate or its concentration in a vacuum evaporator, dialysis of the concentrate against distilled water, and dialyzate lyophilization. As a result, commercial RNase preparations with activities of 30--60 thous. and 160--300 thous. units/g, respectively, were obtained. The enzyme purification was carried out by chromatography and rechromatography on phosphocellulose columns. The resultant RNase of Bac. subtilis had a specific activity of 41--44 thous. units/mg protein, contained no nonspecific phosphodiesterase, DNase, acid or alkaline phosphomonoesterases.
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PMID:[Preparation of extracellular ribonuclease from Bacillus subtilis]. 10 17

Prostaglandin E 9-ketoreductase was purified from chicken heart by ammonium sulfate fractionation, and DEAE-Sephadex, hydroxylapatite and phosphocellulose chromatography. Two peaks of activity were resolved during the phosphocellulose chromatographic step. Both peaks were stimulated by a substance that was not bound to the phosphocellulose column. This stimulatory substance was destroyed by treatment with phosphodiesterase and 0.1 M NaOH. It was heat-stable (100 degrees, 2 min), nondialyzable, and resistant to treatment with pronase, ribonuclease, and deoxyribonuclease; but it was dialyzable after heating or digestion with pronase. Sodium pyrophosphate also enhanced the activities of the prostaglandin E 9-ketoreductases as did angiotensin I; but not angiotensin II. In the presence of 3':5'-cyclic AMP, AMP, or several other ribonucleotides, the enhancing effects of the natural stimulatory substance, sodium pyrophosphate or angiotensin I were blocked, but these ribonucleotides themselves had little effect on the enzymes activity. The substrate specificities of the two prostaglandin E 9-ketoreductases were also studied. Both the 9-keto group and the 15-keto group of 15-ketoprostaglandin F2 alpha could be converted to the corresponding hydroxyl group; the 15-keto group was reduced faster than the 9-keto group. Prostaglandin D2, a prostaglandin with a 9-hydroxyl and an 11-keto group, could not be converted to prostaglandin F2 alpha nor could cyclohexanone be converted to cyclohexanol by the prostaglandin E 9-ketoreductase.
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PMID:Purification and regulatory properties of chicken heart prostaglandin E 9-ketoreductase. 16 95

We have perfused isolated rat livers with hypocalcemic (4.4 mg 100 ml) Krebs-Ringer bicarbonate albumin buffer. After 15 min of perfusion, a substance appeared in the perfusate which decreased rat renal adenylate cyclase activation by parathyroid hormone (PTH). The material in the perfusate was purified greater than 50,000-fold by Bio-Gel P-10 chromatography. The purified antagonist decreased the activation of rat renal cortical adenylate cyclase by PTH, glucagon, and epinephrine 75 to 100%. Concentration response curves for each of the hormones indicated a noncompetitive interaction of the inhibitor with the hormone. The inhibition was not species-specific, as the activation of the parathyroid hormone-responsive adenylate cyclase in cat renal cortex was also abolished by the inhibitor from the perfused rat liver. The inhibitor is a peptide, Mr equal to similar to 1000, which is heat-stable, acid-stable, alkai-labile, and is destroyed by trypsin, leucine aminopeptidase, and elastase. It is not destroyed by phosphodiesterase, 5'-nucleotidase, alkaline phosphatase, neuraminidase, RNase, or phospholipase A. The inhibitor is not produced by isolated rat livers perfused with normocalcemic perfusion media. It is unclear whether the peptide is synthesized by the liver or whether it is a breakdown product of a larger peptide or protein in the liver. This is the first reported peptide inhibitor of adenylate cyclase.
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PMID:Isolation of a unique peptide inhibitor of hormone-responsive adenylate cyclase. 16 24

Plasma membranes from 6 spontaneously metastasizing and 4 non-metastasizing rat mammary carcinomata were isolated by discontinuous sucrose density gradient centrifugation of microsomal pellets. The starting microsomal fraction contained 40-50% plasma membranes as determined by the levels of 5'-nucleotidase activity, with a negligible amount of nuclear (1%), mitochondrial (5%) and lysomal (7%) contamination. Five distinct fractions (F1-F5) were banded at densities 1 X 09, 1 X 13, 1 X 15, 1 X 17 and 1 X 21 at 25 degrees C, in addition to a pellet (F6) obtained by centrifuging at 76,000 g for 17 h. The fractions F1 through F5, all contained various concentrations of membranous structures, while the pellet (F6) contained only amorphous materials as evidenced by electron microscopy. The F3 fraction at the gradient 1 X 15 had the highest specific as well as total activity of the plasma membrane marker enzyme, with aggregates of the least contaminated plasma membranes in vesicular forms. This fraction also had the lowest specific activity for glucose-6-phosphatase (smooth ER marker) and for beta-D-glucuronidase (lysomal marker), and therefore was considered to be the "cleanest" plasma membrane fraction. When the activity of 4 additional plasma membrane marker enzymes, i.e., alkaline phosphatase, phosphodiesterase I, nucleotide pyrophosphatase and alkaline ribonuclease was determined in the same F3 fraction, their levels were significantly lower in every metastasizing tumour than in the non-metastasizing ones, with the enzyme activity decreasing in direct proportion to the metastasizing capacity. On the other hand, the marker enzymes were high in all non-metastasizing tumours, with the activity seemingly increasing with the immunogenicity of tumour cells. There was no significant difference between the 2 groups of mammary tumours in the levels of sialic acid, hexosamine, phospholipid or cholesterol in the plasma membranes. Thus, the level of plasma membrane marker enzymes is considered an accurate indicator for metastasizing capacity in the rat mammary tumour system.
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PMID:Plasma membrane associated enzymes of mammary tumours as the biochemical indicators of metastasizing capacity. Analyses of enriched plasma membrane preparations. 17 19

The complexed 70S ribosomes (monosomes) that accumulate in Escherichia coli after an energy source shift-down were examined in an electron microscope. In all cases, the ribosomes lie at or near one end of a ribonucleic acid (RNA) strand. This messenger RNA (mRNA) has a mean length of 168 nm and a length-average length of 200 nm, sufficient to code for polypeptides of a weight-average molecular weight of 20,000. The length distribution indicates that these strands are a reasonable representation of the population of monocistronic mRNA's of E. coli. The mRNA strands disappear entirely upon digestion with pancreatic ribonuclease, phosphodiesterase I, or polynucleotide phosphorylase. The susceptibility to digestion by 3'-exonucleases indicate that the ribosomes lie at the 5' end of the mRNA strands. These results are consistent with the hypothesis that down-shifted cells have a translational defect at a point subsequent to the binding of ribosomes to mRNA but prior to the formation of the first peptide bond, such that ribosomes remain bound at or near their points of initial attachment to mRNA.
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PMID:Association of messenger ribonucleic acid with 70S monosomes from down-shifted Escherichia coli. 17 81


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