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

---

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

New spin-labeled analogs of nucleoside triphosphates, 8-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)adenosine 5'-triphosphate ((8-AmTEMPO)ATP) and 5-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)uridine 5'-triphosphate ((5-AmTEMPO)UTP), with the probe 4-amino(2,2,6,6-tetramethylpiperidine-N-oxyl) (4-AmTEMPO) attached to C-8 of ATP and C-5 of UTP via a secondary amine bond, were synthesized in 50 and 40% yield, respectively. These analogs showed a single spot by thin layer chromatographic analysis. The absorption spectra of (8-Am-TEMPO)ATP and (5-AmTEMPO)UTP exhibit maxima at 310 and 265 nm, respectively; their X-band EPR spectra have a typical three-line pattern with lines at 3,221, 3,239, and 3,257 Gauss. The intensity ratios for mid to high field lines of the EPR derivative lines were found to be 1.03 +/- 0.02, 1.08 +/- 0.04, and 1.15 +/- 0.07 for 4-AmTEMPO, (8-AmTEMPO)ATP, and (5-AmTEMPO)UTP, respectively. The immobilization of 4-AmTEMPO bound to C-8 of ATP or bound to C-5 of UTP was observed to be 5 and 11%, respectively, as compared with free 4-AmTEMPO. The initial velocity (s-1) of [3H]UMP incorporation into RNA in the presence of [3H]UTP, CTP, GTP, and (8-AmTEMPO)ATP or ATP was measured. The percent incorporation of (8-AmTEMPO)ATP into RNA product by Escherichia coli RNA polymerase using various DNA templates is 68, 66, and 61% for pAR1435 (plasmid containing A1 promoter from T7 DNA), calf thymus DNA, and poly(dA-dT) respectively, as compared with ATP incorporation. The polymerase-catalyzed reaction of (8-AmTEMPO)ATP with (3'-OCH3)UTP yielded 5'-triphosphate delta-amino(2,2,6,6-tetramethylpiperidine-N-oxyl)adenylyl (3'-5')3'-methoxy uridine in the presence of poly(dA-dT). The structure of this spin-labeled dinucleotide was identified by paper chromatographic analysis of the products of phosphodiesterase digestion. These analogs also can be used for the study by EPR spectroscopy of the dynamics of gene transcription catalyzed by RNA polymerases or of other nucleotide-utilizing enzymes.
...
PMID:Spin-labeled nucleotide substrates for DNA-dependent RNA polymerase from Escherichia coli. 165 31

An alkaline 5'-nucleotidase with properties similar to those of membrane-bound 5'-nucleotidase was recovered in soluble form in the postmicrosomal supernatant fraction (cytosol) of rat liver. The enzyme seems to constitute a quantitatively distinct fraction, since the activity in postmicrosomal supernatants was increased by a further 10% by additional homogenization of livers. Lysosomal acid phosphatase activity increased similarly, whereas other membrane-bound marker enzymes alkaline phosphatase, phosphodiesterase I and glucose-6-phosphatase showed no increase when homogenization of liver tissue was continued. Gel-permeation chromatography and pH-dependence studies indicated that enzyme activity in the supernatant fraction with 0.3 mM-UMP or -AMP as substrate at pH 8.1 was about 85 or 100% specific respectively. In regenerating liver the enzyme recovered in soluble form showed decreased specific activity, in contrast with alkaline phosphatase measured for comparison. The nucleotidase activity per mg of cytosolic protein was 2.1 nmol/min with AMP as substrate. The total activity measured in the postmicrosomal supernatant was 1.5% of the homogenate activity measured in the presence of detergent.
...
PMID:The presence and activity in normal and regenerating rat liver postmicrosomal supernatant fraction of an enzyme with properties similar to those of membrane-bound 5'-nucleotidase. 302 68

1. An enzyme preparation from rat-liver microsomes incorporated all four ribonucleotides from the corresponding triphosphates into ribosomal RNA. The reaction was Mn(2+)-dependent, but UMP incorporation also occurred in the presence of Mg(2+). 2. The incorporation of any one ribonucleotide was inhibited by the presence of the other three ribonucleoside triphosphates and by denatured DNA. 3. The product of the reaction consisted of short chains of homopolymer attached to the primer ribosomal RNA. 4. ;Soluble' RNA, synthetic polyribonucleotides, and oligoribonucleotides were also effective primers for CMP incorporation. 5. When phosphodiesterase-treated ;soluble' RNA was the primer, CMP was incorporated into positions usually occupied by the normal terminal trinucleotide sequence of intact ;soluble' RNA, but the enzyme did not synthesize a specific terminal sequence consisting of a defined number of CMP residues.
...
PMID:The incorporation of cytidine 5'-monophosphate and other ribonucleotides by an enzyme preparation from rat-liver microsomes. 429 58

1. s-RNA nucleotidyltransferase incorporated CMP into phosphodiesterase-treated s-RNA more rapidly in the presence of Mg(2+) (10mm) than in the presence of Mn(2+) (2mm). UMP was incorporated more rapidly in the presence of Mn(2+), and at high ionic strength the incorporation of CMP was also more rapid in the presence of Mn(2+). 2. The capacity of phosphodiesterase-treated s-RNA for CMP, UMP and AMP was increased in the presence of Mn(2+). Terminal sequences of more than one UMP or AMP residue were synthesized, but these atypical reactions were inhibited when CTP was added. CMP was incorporated rapidly to form -pCpC terminal sequences and then more slowly as longer chains were formed, but very little CMP was incorporated into s-RNA-pCpCpA. 3. CMP was incorporated into phosphodiesterase-treated 5s RNA and ribosomal RNA to form short chains of polyC attached to the primer RNA. This reaction was inhibited by the presence of s-RNA. 4. A small Mn(2+)-dependent incorporation of CMP was also primed by poly(A).(U) and poly(C).(I).
...
PMID:Altered specificity of transfer-ribonucleic acid nucleotidyltransferase in the presence of manganese. 429 75

Cyclic nucleotides have been implicated in the differentiation and function of the vertebrate retina. In the normal retina of DBA mice, the specific activity of cyclic-nucleotide phosphodiesterase (PDE), with cyclic-AMP as the substrate (cAMP-PDE), increases eightfold between the 6th and 20th postnatal day. Kinetic analysis of retinae from newborn mice reveals a PDE with a single Michaelis constant (K(m)) value for cyclic-AMP (low K(m)-PDE). After the 6th postnatal day, a second PDE with a high K(m) for cyclic-AMP (high K(m)-PDE) can be demonstrated. The appearance and increasing activity of the high K(m)-PDE coincides with the differentiation and growth of photoreceptor outer segments. Additionally, the high K(m)-PDE is shown by microchemical techniques to be concentrated in the photoreceptor cell layer and the low K(m)-PDE within the inner layers of the normal retina. In C3H mice afflicted with an inherited degeneration of the photoreceptor layer, the postnatal increase in the specific activity of cAMP-PDE is substantially lower than in the normal retina. The postnatal increase in the specific activity of cAMP-PDE in two regions of the brain of C3H mice is the same as in the normal strain. A deficiency in high K(m)-PDE activity in the C3H retina is evident on the 7th postnatal day, when the activity of low K(m)-PDE, photoreceptor morphology, and rhodopsin content of these retina are essentially normal. In the adult C3H retina, the PDE activity with cyclic-GMP and cyclic-UMP as substrates is significantly below that of the normal retina. These data indicate that an alteration in cyclic-AMP metabolism occurs before photoreceptor cell degeneration in the retinae of C3H mice.
...
PMID:Cyclic-nucleotide phosphodiesterase: an early defect in inherited retinal degeneration of C3H mice. 434 74

A homogeneous preparation of cyclic CMP phosphodiesterase (Helfman, D. M., Shoji, M., and Kuo, J. F. (1981) J. Biol. Chem. 256, 6327-6334) was found to catalyze the hydrolysis of both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. Hydrolysis of cyclic 2':3'-nucleotides resulted in the formation of both 2'- and 3'-nucleotides, although relative amounts of the products were variable. Hydrolysis of cyclic 2':3'-CMP or cyclic 2':3'-UMP yielded predominantly 3'-nucleotides. In contrast, hydrolysis of cyclic 2':3'-AMP produced equal amounts of 2'- and 3'-nucleotides, while the major product formed from cyclic 2':3'-GMP was 2'-nucleotide. When conventional pyrimidine and purine cyclic 3:5'-nucleotides were used as substrates, the enzyme hydrolyzed specifically the 3'-bond to yield only 5'-nucleotides. The relative rate of hydrolysis of cyclic 2':3'-nucleotides was cyclic CMP greater than cyclic UMP greater than cyclic GMP greater than or equal to cyclic AMP, respectively, whereas that for cyclic 3':5'-nucleotides was cyclic CMP greater than cyclic UMP greater than or equal to cyclic AMP greater than cyclic GMP, respectively. Furthermore, kinetic analysis suggested a single species of catalytic site on the enzyme may be involved in the hydrolysis of both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. These findings indicate that the present enzyme is the first multifunctional phosphodiesterase reported to date that is capable of hydrolyzing such a diversity of cyclic nucleotides.
...
PMID:A homogeneous cyclic CMP phosphodiesterase hydrolyzes both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. 627 51

The effects of various compounds on homogeneous cyclic CMP phosphodiesterase (cyclic CMP-PDE) from pig liver were compared with the effects on cyclic AMP phosphodiesterase (cyclic AMP-PDE) and cyclic GMP phosphodiesterase (cyclic GMP-PDE). Of the conventional inhibitors for AMP-PDE and cyclic GMP-PDE, only Sch 15280 was found to inhibit cyclic CMP-PDE. Nucleoside monophosphates, orthophosphate, and 2':3'-cyclic nucleotides were rather specific and were more effective in inhibiting cyclic CMP-PDE, compared to their effects on cyclic AMP-PDE and cyclic GMP-PDE. On the other hand, nucleoside di-and triphosphates and pyrophosphate (PPi) were less effective in inhibiting cyclic CMP-PDE and were without marked effect on cyclic AMP-PDE and cyclic GMP-PDE. Orthophosphate (Pi) was more potent than CMP, CDP and CTP in inhibiting cyclic CMP-PDE, with a rank order of inhibitory potency of Pi greater than CMP greater than CDP greater than CTP. Of the 3' :5'-cyclic nucleotides examined, cyclic UMP was more specific in inhibiting cyclic CMP-PDE compared to its effect on cyclic AMP-PDE and cyclic GMP-PDE. In all experiments similar results were obtained when either cyclic CMP or cyclic AMP was used as a substrate for this multifunctional cyclic CMP-PDE, supporting the contention that a single catalytic site on the enzyme is responsible for the hydrolysis of both cyclic CMP and cyclic AMP. The present studies further support our original suggestion that cyclic CMP-PDE is a unique enzyme that is distinguishable from the conventional enzymes for purine cyclic nucleotides.
...
PMID:Differential effects of various phosphodiesterase inhibitors, pyrimidine and purine compounds, and inorganic phosphates on cyclic CMP, cyclic AMP and cyclic GMP phosphodiesterases. 627 36

Cyclic nucleotides phosphodiesterase (PDE) was prepared from cerebrum of male rats and its kinetic properties were studied. The phosphodiesterase preparation exhibited two Michaelis constants, 8.7 microM and 83.3 microM. Adenine derivatives such as adenosine, 5'-AMP and 2'(3')-AMP inhibited the PDE activity at concentrations exceeding 7 X 10(-3)M, and 2'-deoxyadenosine inhibited the activity at lower concentrations (Ki = 1.8 X 10(-3)M); its inhibiting efficacy was almost the same as that of theophylline (Ki = 1.9 X 10(-3)M). Guanine derivatives, on the other hand, showed several different effects. Guanosine and 3',5'-cyclic GMP activated the PDE at 10(-5) M and inhibited at concentrations higher than 10(-4)M. 2'(3')-GMP showed no effect, but 5'-GMP activated markedly at concentrations of 10(-3) to 10(-2)M. Thymidine showed slight inhibitory effect, but cytidine or 2'-deoxycytidine had no effect. Uracil derivatives such as uridine, 5'-UMP, 3',5'-cyclic UMP and 2'(3')-UMP activated the PDE at concentrations exceeding 3 X 10(-3) M. These results indicate that individual nucleosides and nucleotides exhibit structure-activity relationship with PDE.
...
PMID:Effects of nucleotides and nucleosides on the activity of cyclic AMP phosphodiesterase from rat brain. 631 97

Fluorescence studies of the intramolecular and intermolecular interactions between aminonaphthylsulfonate and nucleotides of uracil or adenine are described. The fluorescence originates solely from the naphthyl moiety and is intramolecularly quenched by the base, uracil being more effective than adenine. The enzymatic splitting of the molecule into a nucleoside monophosphate and the pyrophosphate product of the aminonaphthylsulfonate removes the intramolecular quenching and, especially in the case of uracil, a drastic increase of the fluorescence intensity results. The intact molecule exists predominantly in the folded form except in cases where electrostatic repulsion exceeds the stacking attraction. This is borne out by the pH dependence and the existence of a pronounced solvent-isotope effect of the fluorescence quantum yield for the uracil derivative at basic pH. At pH values above the pK of the enol proton of the uracil base the fluorescent properties of the intact and phosphodiesterase-digested molecules are very similar. The intermolecular interactions between 1-aminonaphthalene-5-sulfonate with AMP and UMP can be explained on the basis of dynamic quenching (collisional quenching) without any significant participation of ground-state complexes (static quenching). The interaction of the pyrophosphate adduct of 1-aminonaphthalene-5-sulfonate with UMP can best be explained by invoking two interacting nucleotide species: the free nucleotide and a sodium-nucleotide complex.
...
PMID:Fluorescence of intramolecular and intermolecular interactions of aminonaphthyl-sulfonate with nucleotides. 712 95

Mechanical stimulation of one mammary tumor cell in culture induced an increase in its intracellular calcium concentration which spread to surrounding cells. The increase in calcium can also be induced by addition of a solution in which cultured mammary tumor cells were stimulated by repeated pipetting (solution after pipetting cells, SAPC). The activity of the SAPC was completely abolished by treatment with snake venom phosphodiesterase or pyrophosphatase. Uridine triphosphate (UTP), uridine diphosphate (UDP) and ATP (1 microM each) were detected in the SAPC, whereas 5'-UMP and 5'-AMP were produced by phosphodiesterase digestion. A mixture of UTP, UDP and ATP (1 microM each) elicited a calcium response which was comparable to that induced by SAPC, while UTP, UDP or ATP alone at 1 microM elicited a small increase in calcium concentration in mammary tumor cells. Suramin, a competitive antagonist of P2 purinoceptors, diminished the spreading of the calcium wave induced by mechanical stimulation. It also blocked the responses to SAPC, UTP, UDP and ATP. These findings suggest that the mechanical stimulation results in the release of UTP, UDP and ATP into the extracellular space which mediates induction of the spreading calcium response via P2U-type purinoceptors.
...
PMID:The increase in the intracellular Ca2+ concentration induced by mechanical stimulation is propagated via release of pyrophosphorylated nucleotides in mammary epithelial cells. 797 Nov 52


1 2 Next >>

---