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:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclic AMP has been implicated as a regulator of capacitation, but the control of its metabolism in sperm remains obscure. A recent study of mouse sperm has shown capacitation-related changes in the activities of both adenylate cyclase, which increased during incubation, and cyclic nucleotide phosphodiesterase, which decreased. The present study was conducted to extend these observations by measuring phosphodiesterase activity in sperm incubated in media with modified calcium and/or glucose content, conditions known to modulate fertilizing ability. Phosphodiesterase activity of sequential sperm samples, taken first when sperm are essentially uncapacitated and then when they are either partially or completely capacitated, decreased with time under all conditions, and in each case the greater fall in activity was seen in the medium that would support the greater change in fertilizing ability of the sperm population. Sperm washed by centrifugation to remove epididymal fluid also displayed a reduction in phosphodiesterase activity with time. The medium surrounding the sperm contained about half of the total phosphodiesterase activity, as well as 5'-nucleotidase and adenosine deaminase. The crude enzyme preparation showed complex kinetic behavior when assayed over a range of cAMP concentrations, but the reduction in activity with time was seen at all substrate levels. The observed changes in phosphodiesterase activity, together with the increased adenylate cyclase activity seen under these sperm incubation conditions, would increase cAMP availability with time, thus providing further evidence for a fundamental role for cAMP in controlling the events of capacitation.
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PMID:Phosphodiesterase activity of mouse sperm incubated under conditions that modulate fertilizing potential in vitro. 285 27

1. The L-amino acid oxidase, hyaluronidase, alkaline phosphomonoesterase, protease, phosphodiesterase, acetylcholinesterase, phospholipase A and 5'-nucleotidase activities of 47 samples of venoms from all the six species of cobra (Naja), including five subspecies of Naja naja, were examined. 2. The results demonstrated interspecific differences in the venom contents of phospholipase A, acetylcholinesterase, hyaluronidase and phosphodiesterase. These differences in venom enzyme contents can be used for the differentiation of species of the genus Naja. 3. Thus, our results revealed a correlation between the enzyme composition of venom and the taxonomic status of the snake at the species level for the genus Naja.
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PMID:A comparative study of cobra (Naja) venom enzymes. 285 66

The activity of calmodulin as an activator of cAMP phosphodiesterase was assayed. AMP was hydrolyzed by 5'-nucleotidase, and the adenosine formed was measured by both liquid scintillation counting and spectrophotometry at 265 nm. Calmodulin activities measured by the two methods were equivalent, indicating that spectrophotometric assay of calmodulin can be used in place of the isotopic method.
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PMID:A spectrophotometric method for calmodulin assay. 285 35

Purified brush border membrane of Cotugnia digonopora showed the presence of a number of phosphohydrolases. Among these, alkaline phosphatase was extremely active. Other enzymes such as glucose-6-phosphatase, fructose-1,6-diphosphatase, cAMP-phosphodiesterase, 5'-nucleotidase and adenosine-triphosphatase were also active. Observations were made on the activities of various ATPases; whereas the enzyme was activated by Ca++ and Mg++ in an additive manner, its sensitivity to ouabain was negligible. Furthermore, in the presence of EDTA the enzyme activity was quite significant. The treatment of isolated brush border membrane with mebendazole, niclosamide and praziquantel in vitro did not alter the activity of these enzymes. However, treatment of intact worms drastically affected the integrity of the membrane.
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PMID:Enzymes of isolated brush border membrane of Cotugnia digonopora, and their insensitivity to anthelmintics in vitro. 299 11

The effects of the phenothiazine, Stelazine, on Hymenolepis diminuta were investigated. The cestode was incubated for 10 min at 37 degrees C with 1 mM trifluoperazine, in the presence and absence of Ca2+. Assay of brush border enzymes showed that drug treatment lowered the activities of alkaline phosphatase, Ca2+-ATP'ase, 5'-nucleotidase and type 1 phosphodiesterase. This occurred in parallel with a significant reduction in tegumental protein. Under these conditions gross changes in ultrastructural appearance and cellular organization were observed. There was a lack of ordered microtriches and the distal cytoplasm was absent. Glycogen granules were scattered throughout the cytoplasm within the subtegumental layer. The connective tissue also appeared to be in some disarray. The effects of Stelazine appeared to be dependent on time and were significantly increased when Ca2+ was included in the incubation medium. Incubation with the less hydrophobic phenothiazine trifluoperazine sulphoxide had minimal effect on the integrity of the cestode. The results reported here support the premise that certain phenothiazines may be considered as potential cestocidal agents.
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PMID:Biochemical and ultrastructural investigation of the effect of Stelazine (trifluoperazine) on Hymenolepis diminuta (Cestoda). 302 50

Among all the purified components from A. acutus venom, including ADPase, 5'-nucleotidase, phospholipase A2 and fibrinogenases, only the venom ADPase (50-100 micrograms/ml) shows marked inhibitory action on ADP (10 microM)-, collagen (10 micrograms/ml)- and sodium arachidonate (100 microM)-induced platelet aggregations of rabbit platelet-rich plasma. The venom 5'-nucleotidase (100 micrograms/ml) inhibited ADP-induced platelet aggregation by 31 +/- 4% (n = 4, P less than 0.05). Fibrinogenolytic enzymes (fractions I and IX, 100 micrograms/ml) did not significantly inhibit platelet aggregation induced by ADP (10 microM), collagen (10 micrograms/ml) or sodium arachidonate (100 microM). However, when the fibrinogenase (fraction IX, 100 micrograms/ml) was preincubated with platelet-rich plasma for 30 min it inhibited collagen (20 micrograms/ml)- and ADP (10 microM)-induced platelet aggregations by 34 +/- 9% (n = 4, P less than 0.05) and 35 +/- 6% (n = 4, P less than 0.05), respectively. The phospholipase A2 (100 micrograms/ml) did not affect platelet aggregation. The venom ADPase is a single chain polypeptide with a molecular weight of 94,000. The specific ADPase activity is estimated to be 4.3 mu moles Pi/min/mg of protein. It also possesses phosphodiesterase and weak 5'-nucleotidase activities.
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PMID:Platelet aggregation inhibitors from Agkistrodon acutus snake venom. 303 52

Inhibition of 3':5'-cyclic-AMP-5'-nucleotidohydrolase (EC 3.1.4.17) type II (cAMP-phosphodiesterase) by sodium molybdate was studied: While determination of inorganic phosphate and 5'-ribonucleotide phosphohydrolase (5'-nucleotidase) (EC 3.1.3.5) activity was not disturbed by sodium molybdate in concentrations up to 10 mM, cAMP-phosphodiesterase was inhibited by millimolar concentrations of molybdate. The half maximal effect was observed at about 2 mM sodium molybdate (0.75 mM cAMP in the assay).
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PMID:Inhibition of cAMP-phosphodiesterase by molybdate. 303 26

The enzymatic activities of four samples of Malayan cobra venom were investigated. There was significant variation in the contents of L-amino acid oxidase, alkaline phosphomonoesterase, acetylcholinesterase, phospholipase A, 5'-nucleotidase and hyaluronidase. The phosphodiesterase content was, however, constant. Storage of the lyophilized venom powder at 25 degrees C for 1 month did not affect the enzymatic activities. The venom enzymatic activities were generally also stable at 4 degrees C in 0.85% saline solution. After incubation at 37 degrees C for 39 days in 0.85% saline solution, the venom still retained considerable amounts of enzymatic activities. SP-Sephadex C-25 ion-exchange chromatography of the venom showed that the phospholipase A, L-amino acid oxidase, 5'-nucleotidase, phosphodiesterase and alkaline phosphomonoesterase exist in multiple forms.
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PMID:Enzymatic activities of Malayan cobra (Naja naja sputatrix) venoms. 343 96

The enzyme contents of four venom samples of Calloselasma rhodostoma were analyzed. The venoms contained phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, protease, phospholipase A, L-amino acid oxidase, hyaluronidase, arginine ester hydrolase, arginine amidase, fibrinogenase and coagulant enzyme activities. There is significant variation in the contents of coagulant enzyme, arginine ester hydrolase, hyaluronidase, protease, phosphodiesterase, alkaline phosphomonoesterase and L-amino acid oxidase. DEAE-Sephacel ion exchange chromatography of the venom resolved it into eight major protein fractions. The eight fractions were heterogeneous and exhibited more than one type of enzymatic activity. The 5'-nucleotidase, alkaline phosphomonoesterase, protease, coagulant enzyme, arginine ester hydrolase, arginine amidase and fibrinogenase exist in multiple forms.
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PMID:Enzymatic activities of Calloselasma rhodostoma (Malayan pit viper) venom. 375 Mar 51

The release of enzymes by osmotic shock from Escherichia coli strain 30E, an unsaturated fatty acid auxotroph, was examined in culture supplemented with either cis- or trans-unsaturated fatty acids. Cultures grown in oleate-supplemented medium release a large fraction of the total cyclic phosphodiesterase, acid hexose phosphatase, and 5'-nucleotidase following osmotic shock. Cultures grown in elaidate-supplemented medium release much less of these same enzymes after shock treatment. Cultures grown with either supplementation show total release of these enzymes upon conversion to spheroplasts, demonstrating that the enzymes are in the periplasmic space in both cases. Cultures grown with either oleate or elaidate as fatty acid source were washed and suspended in medium containing the other isomer. The change from oleate to elaidate resulted in a rapid decrease in ability of the cells to release the three enzymes after osmotic shock so that within a 25% increase in cell mass the culture responded to osmotic shock as would a culture grown overnight in elaidate-supplemented medium. The reverse experiment resulted in a gradual increase in the ability of the cells to respond to osmotic shock. The outer membrane of E. coli is altered by the incorporation of elaidate, as indicated by electron microscopic data.
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PMID:Effects of fatty acid substitution on the release of enzymes by osmotic shock. 411 23


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