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)

Escherichia coli was grown in chemostat culture under glycerol-limited and ammonium-limited conditions at growth rates between 0.1 and 0.5 h-1. At steady state, the concentrations of cyclic AMP and cyclic GMP and the activities of four constitutive enzymes (glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, NADH oxidase and cyclic phosphodiesterase) were determined in the organism. Addition of exogenous cyclic AMP, cyclic GMP or phencyclidine perturbed the steady state and caused inhibition or stimulation of synthesis of phosphodiesterase and isocitrate dehydrogenase. A novel hypothesis is proposed to account for the ability of bacteria to regulate the synthesis of constitutive enzymes with cyclic nucleotides and possibly other small molecules.
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PMID:Cyclic AMP and cyclic GMP control of synthesis of constitutive enzymes in Escherichia coli. 628 44

The substrate specificity of diadenosine 5',5"'-P1,P4-tetraphosphate pyrophosphohydrolase from Physarum polycephalum for dinucleoside polyphosphates has been determined by high-performance liquid chromatography (HP-LC). Elution of a strong anion-exchange resin with a pH and ionic strength gradient of ammonium phosphate separates a series of monoadenosine and diadenosine polyphosphates. Most of the corresponding guanine nucleotides are also resolved on this HPLC system. One mole each of Ap4A and Gp4G is symmetrically hydrolyzed to 2 mol of ADP and GDP, respectively. Ap3A, Ap5A, Ap6A, and Ap4 are hydrolyzed, and in each case ADP is one of the products. Gp3G, Gp5G, Gp6G, and Gp4 are also substrates, and in each case GDP is one of the products. AMP, ADP, ATP, Ap2A, ADPR, GMP, GDP, GTP, NAD+, and NADP+ are not substrates. No hydrolysis of the cap dinucleotides m7Gp3Am and m7Gp3Cm was detected by HPLC. Diadenosine tetraphosphate pyrophosphohydrolase preparations were also assayed for adenylate kinase, nucleotide diphosphate kinase, NAD(P)+ pyrophosphohydrolase, phosphodiesterase, cyclic nucleotide phosphodiesterase, phosphatase, and ribonuclease activities. These enzymic activities were not detectable in diadenosine tetraphosphate pyrophosphohydrolase. The symmetrical hydrolysis of Ap4A and Gp4G is an unique catalytic property that distinguishes diadenosine tetraphosphate pyrophosphohydrolase from P. polycephalum from diadenosine tetraphosphate phosphohydrolases from other organisms.
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PMID:Diadenosine 5',5"'-P1,P4-tetraphosphate pyrophosphohydrolase from Physarum polycephalum. Substrate specificity. 629 57

Human blood serum was found to contain two enzymes which hydrolyze various phosphate diester and phosphonate ester bonds. The enzymes were isolated by butanol extraction, ammonium sulfate precipitation, column chromatography and gel electrophoresis. Zymograms showed that one of these enzymes is serum alkaline phosphatase and the other is a 'true' phosphodiesterase I. Serums of 25 persons showed no polymorphisms for either activity. Alkaline phosphatase hydrolyzes phenolic thymidine 5'-nucleotide esters readily, but phenylphosphonate esters very poorly. Serum phosphodiesterase I prefers phenylphosphonate esters to nucleotide diesters, and has no detectable monoesterase activity.
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PMID:Tissue specificity of human phosphodiesterase. I. Blood serum. 630 33

Extracts of human intestinal mucosa were examined for their ability to hydrolyze various phosphodiester, phosphomonoester and phenylphosphonate ester linkages. Enzymes carrying out these reactions were partially purified by butanol extraction, ammonium sulfate precipitation and DEAE-cellulose chromatography, and examined for polymorphism on polyacrylamide gels. Two species of alkaline phosphatase and at least five species of PDE I were identified. Antibodies to purified bovine intestinal phosphatase and phosphodiesterase were found specific for the respective human enzymes.
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PMID:Tissue specificity of human phosphodiesterase. II. Intestinal mucosa. 630 34

A calmodulin-sensitive phosphodiesterase was purified from bovine brain. The purification procedure involved ammonium sulphate fractionation, two chromatographic steps on DEAE-cellulose, gel-filtration on Sephadex G-200, and finally one DEAE-cellulose run, and gave a 2300-fold purification. The purified phosphodiesterase had a Vmax for cyclic AMP of 126 mumol/mg protein X min. and was activated 8-fold by addition of calmodulin and calcium. According to SDS-electrophoresis the purified enzyme contained one major peptide of 59,000 daltons, but the preparation was not homogeneous. The enzyme was characterized kinetically and with regard to the effect of cations, pH temperature, and nucleotides. Furthermore, the influence in vitro on enzyme activity of several classes of drugs, e.g. antidepressants, neuroleptics, antiallergics, platelet inhibitors, and some "reference phosphodiesterase inhibitors" was investigated.
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PMID:Characterization of and drug influence on a calmodulinsensitive phosphodiesterase purified from bovine brain. 631 Sep 59

"Low Km" cAMP phosphodiesterase and cGMP-stimulated cyclic nucleotide phosphodiesterase activities were partially purified from calf liver supernatant by chromatography on DEAE-cellulose and DEAE-Sepharose and ammonium sulfate precipitation. The low Km phosphodiesterase was not retained on N6-H2N(CH2)2-cAMP-agarose and could be separated from the cGMP-stimulated phosphodiesterase which was absorbed by this matrix. From the proteins that did not bind, two distinct low Km cAMP phosphodiesterases were separated on Ultrogel AcA 34. One form (fraction C) hydrolyzed cAMP with an apparent Km of approximately 0.5 microM and was very sensitive to inhibition by cGMP. Lineweaver-Burk plots of cAMP hydrolysis by a second form (fraction B) were nonlinear, with an apparent low Km component of approximately 2 microM. This form was rather insensitive to inhibition by cGMP. With both fractions, hydrolysis of cAMP relative to cGMP was much greater at low (approximately 1 microM) than at high (approximately 100 microM) substrate concentrations. Maximal velocities for cAMP and cGMP were similar. From sedimentation equilibrium, the apparent weight-average molecular weight of fraction B was estimated as 174000, and that of fraction C was 85000. Another fraction (A) of cAMP phosphodiesterase eluted at the void volume of the AcA 34 column. On the basis of the relative affinities for cAMP and cGMP and inhibition by cGMP, fraction A is most likely an aggregated form of fraction B. No apparent interconversion of fractions A, B, or C was observed on high-performance liquid chromatography.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Selective inhibition of two soluble adenosine cyclic 3',5'-phosphate phosphodiesterases partially purified from calf liver. 632 51

Two new extracellular nucleases, nucleases SM1 and SM2, were purified from the culture fluid of S. marcescens kums 3958, a fresh clinical isolate. The purification was carried out by the following steps; ammonium sulfate precipitation, and DEAE-cellulose and Sephadex G-100 column chromatography. At the final step, nucleases SM1 and SM2 were purified about 3,700- and 1,000-fold, respectively. They were free from phosphomonoesterase and phosphodiesterase activities. The pIs were 8.1 and 7.5 for nucleases SM1 and SM2, respectively. The molecular weight was estimated to be 35,000 for both enzymes by SDS-polyacrylamide disc gel electrophoresis. The results of amino acid analyses showed that both the threonine and serine contents were higher in nuclease SM2 than in SM1. Furthermore, nuclease SM1 was more stable than nuclease SM2 at 4 degrees C. The other properties of the two enzymes were similar; pH optimum (8.0), Mg2+ or Mn2+ for activation, and inhibition by chemical reagents such as EDTA and pyrophosphate. No significant difference was found in base specificity between nucleases SM1 and SM2. Both enzymes specifically degraded double-stranded homopolymers, especially poly(I). poly(C), as well as yeast RNA and calf thymus DNA. They hardly degraded, however, single-stranded homopolymers such as poly(dA), poly(G), and poly(U).
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PMID:Isolation and characterization of nucleases from a clinical isolate of Serratia marcescens kums 3958. 635 Feb 76

An acid deoxyribonuclease has been purified from rat small intestinal mucosa by a procedure including ammonium sulfate fractionation, chromatographies on DEAE-cellulose, CM-cellulose and SE-Sephadex and finally isoelectric focusing. Polyacrylamide gel electrophoresis of the purified enzyme preparation showed one major and two minor bands, and the enzyme activity corresponded to one of the minor bands. The enzyme preparation was free of contaminating DNase I, DNase III, alkaline RNase, acid and alkaline phosphatases and nonspecific phosphodiesterase, but slight activities of DNase IV and acid RNase were detected. The enzyme did not require divalent cations for activity, had a pH optimum of 4.5 in 0.33 M sodium acetate buffer, and had an optimum temperature of 50 to 60 degrees C when assayed for 30 min. The rate of hydrolysis of native DNA was about 2.5-fold faster than that observed with denatured DNA. Its molecular weight was found to be 9.0 +/- 0.1. The enzyme catalyzes the endonucleolytic cleavage of native and denatured DNA, yielding oligonucleotides which have an average chain length of about 7, and which contain 3'-phosphoryl termini. The mode of action of the enzyme is double-strand scission.
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PMID:Purification and properties of an acid deoxyribonuclease from rat small intestinal mucosa. 663 Jan 62

DNases A1 and A2 have been purified to homogeneity from the hepatopancreas of Achatina fulica by a series of steps: acetate buffer extraction, ammonium sulfate precipitation and column chromatography on hydroxylapatite, phosphocellulose, Blue-Sepharose, and poly(A)-Sepharose. The purified enzymes are free of acidic phosphomonoesterase, phosphodiesterase, and RNase activities. They are slightly acidic glycoproteins with identical isoelectric point (6.90). On 0.1% SDS gel electrophoresis, DNase A2 had a molecular weight of 30,000 when dissolved in 1% SDS, but it had molecular weights of 17,500, 8,000, and 4,800 when dissolved in 1% SDS and 1% 2-mercaptoethanol. This was evidence that the enzyme consists of three different subunits joined by interchain disulfide bonds. DNases A1 and A2 are endonucleases working at acidic pH (3.5--6.0) and do not require divalent cations for their activities. The enzymes degrade poly(dA) 5 times faster and poly(dT) 3 times faster than heat-denatured DNA under optimal conditions but do not appreciably digest poly(dG) and poly(dC). We developed an analytical procedure for oligodeoxynucleotides by high-performance liquid chromatography. The phosphomonoester end group and the mode of degradation were examined by the method. The termini produced by the enzymes have 3'-phosphoryl and 5'-hydroxy end groups. The products of exhaustive hydrolysis contain di-, tri-, tetra-, and pentanucleotides and mononucleotide was barely detected. The hydrolyzing activities of DNases A1 and A2 are stimulated by polyamines such as spermine, spermidine, and putrescine, but are inhibited by synthetic polynucleotides and various drugs. Adenosine deaminase highly active on oligoadenylic acids was found in a crude DNase A fraction. The enzyme preparation has higher activity on 3'-adenylic acid than on 5'-adenylic acid. The first adenosine residue of oligoadenylic acids was deaminated considerably more rapidly than the second or succeeding ones.
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PMID:DNase A, a poly(dA) and poly(dT)-specific deoxyribonuclease from Achatina fulica. Purification and characterization. 733 15

1. Acid extrusion through Na(+)-H+ exchange was studied in the sheep cardiac Purkinje fibre (bathed in Hepes-buffered solution, nominally free of CO2-HCO3-) by examining (i) intracellular pH (pHi) recovery from an intracellular acid load (induced by 20 mM NH4Cl prepulse) and (ii) the rate of rise of intracellular Na+ activity (aiNa) following the ammonium prepulse (used as an estimate of apparent Na+ influx on Na(+)-H+ exchange). The pHi and aiNa were recorded using ion-selective microelectrodes. 2. The pHi recovery and rise of aiNa were both greatly slowed in the presence of 2-deoxyglucose (DOG; glucose-free solution), an inhibitor of glycolysis, indicating inhibition of Na(+)-H+ exchange. 3. Cyanide moderately slowed pHi recovery rate but did not significantly affect the rise of aiNa. Estimates of beta 1 (intracellular buffering power) indicated an increase of approximately 50% in the presence of cyanide; such an increase accounts for most of the observed slowing of pHi recovery. It is concluded that oxidative inhibition with cyanide does not inhibit Na(+)-H+ exchange. 4. Intracellular ATP, measured from luciferin-luciferase luminescence, was reduced by a similar amount (approximately 70%) by either DOG or cyanide. This suggests that, if intracellular ATP (ATPi) reduction is the cause of exchanger inhibition by metabolic inhibitors, then ATPi generated glycolytically is more important for activation of the exchange. 5. 3-Isobutyl-1-methylxanthine (IBMX; a non-specific phosphodiesterase inhibitor which can elevate intracellular [cAMP]) slowed acid extrusion and reduced apparent Na+ influx by a similar amount, whereas addition of sodium nitroprusside (to elevate intracellular [cGMP]) had no effect, suggesting that raising intracellular [cAMP] downregulates Na(+)-H+ exchange, whereas raising intracellular [cGMP] does not. 6. Application of trifluorperazine (TFP; a non-specific calcium-calmodulin inhibitor) completely reversed the inhibitory effects of IBMX upon pHi recovery and aiNa. Under control conditions (no IBMX), TFP had no effect on pHi recovery or upon resting pHi. 7. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) had no significant effect on pHi recovery or apparent Na+ efflux. 8. We conclude that inhibition of glycolysis or elevation of cAMP produces downregulation of Na(+)-H+ exchange in the cardiac Purkinje fibre. Possible reasons for the lack of inhibitory effect of oxidative inhibitors are discussed.
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PMID:Effect of metabolic inhibitors and second messengers upon Na(+)-H+ exchange in the sheep cardiac Purkinje fibre. 752 44


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