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)

Four 25-nt oligonucleotides consisting of sequences of dA and dT (D1-4) have been synthesized. As shown in a companion paper (Rippe et al., 1989), the two combinations D1.D3 and D2.D4 form normal antiparallel duplexes, whereas the pairs D1.D2 and D3.D4 constitute duplexes with the same sequences, but with the two strands parallel to each other. The activities of the following DNA processing enzymes and chemical reagents on the parallel stranded (ps) and antiparallel stranded (aps) duplexes were tested. (i) The restriction endonucleases DraI, SspI, and MseI do not cut the ps duplexes. (ii) DNase I and exonuclease III exhibit a much lower activity with the ps duplexes. (iii) The nuclease activities of S 1 nuclease, micrococcal nuclease (S 7), phage lambda 5'-exonuclease, and the 3'-5' nuclease activity of Escherichia coli DNA polymerase I and its large fragment are higher with the ps than with the aps substrates. (iv) Bal 31 nuclease and the chemical nuclease 1,10-phenanthroline-copper ion [(OP)2Cu+] degrade ps-DNA and aps-DNA at approximately the same rate but show preferred cutting sites only with the aps molecules. (v) The iron(II)-EDTA complex has equivalent nuclease activities with the ps and the aps molecules. (vi) The ps duplex is not a substrate for blunt-end ligation with phage T4 DNA ligase.
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PMID:Substrate properties of 25-nt parallel-stranded linear DNA duplexes. 255 23

Cyclic AMP phosphodiesterase (PDE) partially purified from roots of Vigna mungo exhibited optimum activity at pH 5.5 to 6.0 and maximum enzyme activity at 50 degrees C. Levels of PDE activity in roots remained relatively constant from the first to the eleventh day after germination; on the twelfth day there was a 400% increase in PDE activity. The enzyme was stable for at least 48 hours at 28 degrees C, retaining 92% of its original activity. Plant growth hormones including gibberellic acid, indoleacetic acid and kinetin at 1.0 and 10.0 microM concentrations did not have any significant effect on enzyme activity. Nucleotides tested including cyclic 2'3' AMP, cyclic 2'3' GMP completely abolished enzyme activity at 1.0mM while cyclic 3'5' GMP, cyclic 3'5' GMP, 2'deoxy 5' ATP, 2'deoxy 5'GTP and 5'ADP were also inhibitory to the enzyme. The enzyme was stimulated by Mg2+, Fe2+ and NH4+ while Cu2+ and Fe3+ were inhibitory. Theophylline, caffeine, phosphate, pyrophosphate and EDTA were inhibitory to the enzyme.
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PMID:Properties of a cyclic 3'5'-nucleotide phosphodiesterase from Vigna mungo. 255 28

The effects of Cd2+ on Ca2+-sensitive myosin ATPase activity were examined. In the absence of Ca2+, the Ca2+-dependent myosin ATPase activity was enhanced by Cd2+ to the same extent as with Ca2+ at concentrations ranging from 10(-6) to 10(-3) M. At 10(-2) M, however, no activation was observed. Zn2+, Co2+, and Sr2+ also activated the myosin ATPase. Sr2+ and Co2+ were less effective. Hg2+, Cr3+, and Cu2+ were essentially inactive. In the presence of below 10(-3) M Ca2+, the increase in the enzyme activity observed on the addition of Cd2+ was in addition to that caused by Ca2+ alone. The ability of metal ions to activate myosin ATPase was compared with that to activate calmodulin-dependent cAMP phosphodiesterase. The activating effects of the metal ions tested were in the order of Ca2+ greater than Cd2+ greater than Zn2+ greater than Co2+ greater than Sr2+ for Ca2+-sensitive myosin ATPase and Ca2+ greater than Cd2+ greater than Sr2+ greater than Zn2+ greater than Hg2+ greater than Co2+ for cAMP phosphodiesterase. Cd2+ activated both enzyme activities most efficiently among the metal ions tested except Ca2+. These results indicate that Cd2+ is able to substitute for Ca2+ in the case of Ca2+ dependent enzymes, regardless of whether or not calmodulin participates in the activating process.
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PMID:Enhancement of Ca2+-sensitive myosin ATPase activity by cadmium. 282 3

The calcium-dependent phosphatidylinositol phosphodiesterase activity of skeletal muscle cytosol was determined. The enzyme was inhibited by Zn2+, Cu2+ and Pb2+ ions but Mg2+ and Mn2+ were without effect. The antimalarial drugs chloroquine and the quinine and the aminoglycoside antibiotics gentamicin and neomycin all of which, like Zn2+, have been shown to block neuromuscular transmission, also inhibited the enzyme.
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PMID:Inhibition of phosphatidylinositol phosphodiesterase activity in skeletal muscle by metal ions and drugs which block neuromuscular transmission. 299 Apr 87

Crotalus ruber ruber venom contains several different proteases, and the proteolytic activity of the crude venom is 6-15 times greater in adult than in juvenile venom. Venom samples were assayed for proteolytic, phosphodiesterase, L-amino acid oxidase and elastinase-like activities and were subjected to gel filtration on BioGel P-100. Two major size classes of proteases were resolved (mol. wt 67,000 and 20,500). EDTA, N-ethylmaleimide (N-EM) and 1,10-phenanthroline inhibited proteolytic activity of crude venom, and EDTA, Zn2+ and Cu2+ inhibited proteolytic activity of the fractionated venom.
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PMID:Fractionation of red diamond rattlesnake (Crotalus ruber ruber) venom: protease, phosphodiesterase, L-amino acid oxidase activities and effects of metal ions and inhibitors on protease activity. 299 22

The effect of some reductones such as ascorbic acid (AsA), triose reductone (TR), epinephrine (Ep) and their derivatives on cyclic 3', 5'-adenosine monophosphate phosphodiesterase (cAMP PDE) was studied in the presence or absence of Cu2+. AsA, TR, Ep and the reductones related to them inhibited cAMP PDE activity. Among the reductones, TR showed the highest inhibition. AsA, 5-methyl-3,4-dihydroxytetrone, pyrocatechol, p-hydroxyquinone and resorcinol had a relatively high inhibiting activity. The type of inhibition of AsA, TR and Ep was uncompetitive, competitive and noncompetitive, respectively. Cu2+ enhanced the inhibitory action of the reductones markedly and altered the type of inhibition of the reductones.
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PMID:Effect of reductones on cyclic 3', 5'-adenosine monophosphate phosphodiesterase. 299 29

A technique is described, involving tissue dissociation and micro-dissection, for the isolation of interlobular ducts from the pancreas of copper-deficient rats. The average length and outside diameter of the isolated ducts were 589.0 +/- 18.6 and 78.1 +/- 1.6 micron (mean +/- S.E.M., n = 425) respectively. Between twenty and fifty ducts could be obtained from each pancreas. Frequently, the smaller intralobular ducts, which had outside diameters of between 15 and 25 micron, were observed as branches of the interlobular ducts. Light and electron microscopy showed that the isolated ducts were structurally intact, and that the epithelial cells possessed all the typical ultrastructural features of duct cells within the gland of copper-replete rats. The isolated ducts consumed oxygen at a rate of 2.27 +/- 0.55 ml O2/min X 100 g wet weight duct epithelium (n = 6). The concentrations of ATP, ADP and AMP in the ducts were 3.78 +/- 0.81, 0.68 +/- 0.19 and 0.41 +/- 0.13 mmol/l duct epithelium (n = 8) respectively. These data give values for ATP:ADP and ATP:AMP ratios of 5.6:1 and 9.2:1 respectively, and an energy charge of 0.85 +/- 0.01 (n = 8) suggesting that the epithelial cells are healthy and in a stable metabolic state. In the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.67 mM), the basal concentration of cyclic AMP in the isolated ducts was 17.4 +/- 0.7 mumol/l duct epithelium (n = 3). Secretin (0.1 nM-1 microM) caused a dose-related increase in cyclic AMP content up to a maximum of 376.0 +/- 85.3 mumol/l duct epithelium (n = 4). This indicates that the epithelial cells possess secretin receptors, and that these receptors can be functionally linked to adenylate cyclase.
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PMID:Isolation of ducts from the pancreas of copper-deficient rats. 301 21

Quercetin is a naturally occurring flavonoid, chemically related to cromolyn. Quercetin has been shown to inhibit antigen- and mitogen-induced histamine release from rat mast cells and basophils of subjects with hay fever, to increase cyclic adenosine monophosphate (AMP) in Ehrlich ascites tumor cells and to inhibit phosphodiesterase and certain adenosine triphosphatase (ATPase) systems. We have studied the effect of quercetin on mouse T cell responses. When 5 x 10(-6) to 5 x 10(-5) M quercetin is present throughout either allogeneic mixed leukocyte culture (MLC) or cytotoxic T lymphocyte (CTL) assay culture, inhibition of in vitro CTL generation or effector function results, respectively (inhibition is 75-100% at 2 x 10(-5) M and 100% at 5 x 10(-5) M). Quercetin also inhibits concanavalin A-induced DNA synthesis. Addition of Cu2+ strongly blocks the effects of quercetin in all systems tested, in a concentration dependent fashion, while Mg2+ and Ca2+ have little or no effect and Mn2+ and Co2+ have a significant but slight blocking effect on quercetin-mediated inhibition of both CTL generation and function. In kinetic studies, evidence was obtained for the existence of a major quercetin-sensitive step in CTL induction, between 3 and 24 hr of the MLC.
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PMID:Quercetin inhibition of the induction and function of cytotoxic T lymphocytes. 621 17

We have studied the interaction between some heavy metal ions, as compared with earth alkali ions, and calmodulin, a tissue protein which binds Ca2+ and mediates some of its effects. 1. Calmodulin dependent phosphodiesterase was activated with Pb2+, Ca2+, Sr2+, Ba2+, and Cd2+ (EC50 about 0.8 microM). The maximal activation achieved decreases in the order given. Hg2+, Sn2+, Fe2+, Cu2+, Ni2+, Bi3+, and Sb3+ up to 20 microM did not activate. 2. Pb2+ can replace Ca2+ with respect to the calmodulin-dependent phosphorylation of brain membranes. With high Pb2+ concentrations, phosphorylation was inhibited. 3. Calmodulin binding to brain membranes was enhanced with concentrations below 10(-4)M in the following order: Pb2+ greater than or equal to Ca2+ approximately Sr2+ greater than Cd2+ greater than Mn2+ greater than Ba2+. In contrast Mg2+, Hg2+, Sn2+, Fe2+, Ni2+, Co2+, and Cu2+ triggered, if at all, a non-saturable binding of calmodulin. 4. In the flow-dialysis, other ions competed with 45Ca2+ binding to calmodulin in the following order: Pb2+ approximately Ca2+ greater than Mn2+, Ba2+, Cd2+, Sr2+. Thus among the ions investigated Pb2+ is a fully potent substitute for Ca2+ in every calmodulin-dependent reaction investigated. Cd2+ is always much less potent. The earth alkali ions Sr2+ and Ba2+ take an intermediate position. It remains to be shown whether calmodulin is merely a storage site for Pb2+, or whether the resulting functional changes play a role in Pb2+ poisoning.
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PMID:Lead and other metals can substitute for Ca2+ in calmodulin. 631 31

Enzymatic activity which hydrolyzes diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) yielding ADP has been identified in extracts of eubacteria, Escherichia coli and Acidaminococcus fermentans, and of a highly thermophilic archaebacterium, Pyrodictum occultum. Specific Ap4A (symmetric) pyrophosphohydrolase from Escherichia coli K12 has been purified almost 400-fold. The preparation was free of phosphatase, ATPase, phosphodiesterase, AMP-nucleosidase, and adenylate kinase. The Ap4A pyrophosphohydrolase molecular weight estimated by gel filtration is 27,000 +/- 1,000. Activity maximum is at pH 8.3. The Km value computed for Ap4A is 25 +/- 3 microM. The sulfhydryl group(s) is essential for enzyme activity. Metal chelators, EDTA, and o-phenanthroline, inhibit Ap4A hydrolysis; I0.5 values are 3 and 50 microM, respectively. Co2+ is a strong stimulator with an almost 100-fold increase in rate of Ap4A hydrolysis and a plateau in the range of 100-500 microM Co2+, when compared with the nonstimulated hydrolysis. Other transition metal ions, Mn2+, Cd2+, and Ni2+, stimulate by factors of 8, 3.5, and 3.5, respectively, with optimal concentrations in the range 200-500, 2-5, and 4-8 microM, respectively. Zn2+, Cu2+, and Fe2+, up to 30 microM, are without effect and they inhibit at higher concentrations. Mg2+ or Ca2+, in the absence of other divalent metal ions, are weak stimulators (1.5-fold stimulation occurs at 1-2 mM concentration), but act synergistically with Co2+ at its suboptimal concentrations. Stimulation in the presence of 10 microM Co2+ and either 1 mM MgCl2 or CaCl2 increases up to 75-fold. The same degree of synergy is found at 10 microM Co2+ and either 2-5 mM spermidine or 0.5-1.5 mM spermine. Besides Ap4A, bacterial Ap4A pyrophosphohydrolase hydrolyzes effectively Ap5A and Gp4G, and, to some extent, p4A, Ap6A, and Ap3A yielding in each case corresponding nucleoside diphosphate as one of the products.
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PMID:Catabolism of diadenosine 5',5"'-P1,P4-tetraphosphate in procaryotes. Purification and properties of diadenosine 5',5"'-P1,P4-tetraphosphate (symmetrical) pyrophosphohydrolase from Escherichia coli K12. 631 72


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