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)

The distribution of [3H]oxytocin binding sites among various subcellular fractions of rat myometrium paralleled the distribution of 5'-nucleotidase, a plasma membrane marker enzyme, but not of NADPH-cytochrome c reductase or succinate-cytochrome c reductase, which are endoplasmic reticulum and mitochondrial marker enzymes respectively. [3H]Oxytocin binding to the most enriched plasma membrane fraction showed the degree of selectivity with respect to hormone analogues that is expected for the oxytocin receptor. The binding of oxytocin to this fraction showed an apparent Kd of 1.98 X 10(-9) M and a capacity of 1.28 pmol mg-1. It is concluded that the oxytocin receptor is located on the plasma membrane of the smooth muscle cells of the rat uterus.
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PMID:Localization of the oxytocin receptor in the plasma membrane of rat myometrium. 20 28

Certain phosphatases have been localized by histochemical techniques in various tissues of a pigeon cestode, Raillietina (Raillietina) johri. Acid phosphatase (AcPase), alkaline phosphatase (AlPase) and adenosine triphosphatase (ATPase) were present in almost all structures: tegument; subtegumental muscles; subtegumental cells; excretory canal; testes; sperm ductules; vas deferens; cirrus sac; cirrus; ovary; receptaculum seminis; vagina; vitelline gland cells; oocytes; uterus; embryonated eggs. AlPase was absent in parenchyma, spermatocytes, spermatids and spermatozoa. AlPase activity was more intense in the tegument of mature gravid proglottides. AcPase and ATPase were visualized in various stages of spermatogenesis of the parasite. ATPase activity was also observed in chromosomes. 5'-nucleotidase (AMPase) activity was restricted to embryonated eggs only. Functional significance of these phosphatases is discussed.
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PMID:Histochemical studies on Raillietina (Raillietina) johri (Cestoda: Davaineidae). I. Nonspecific and specific phosphatases. 22 30

A membrane fraction with sarcolemmal properties was purified from the smooth muscle layers (myometrium) of rat uterus by successive differential and equilibrium centrifugation in sucrose. The putative sarcolemmal fraction was identified by iodination with [125I]iodosulfanilic acid, had an equilibrium density of 1.15, and was enriched in enzyme activities usually associated with the plasma membrane including 5'-nucleotidase (EC 3.1.3.5) and (Na+ + K+) ATPase (EC 3.6.1.3). These membranes were free of mitochondrial or nuclear membrane contamination, suggesting the relative enrichment of sarcolemmal membranes in the fraction. Proteins of the membranes were heterogeneous with respect to molecular weight, but only a few were labelled when intact muscle was radioiodinated. Uniform resistance of sarcolemmal proteins to trypsin digestion and salt extraction suggested many are tightly bound or intrinsic membrane proteins and was a further indication of the homogeneity of membranes in this fraction.
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PMID:Smooth muscle cell sarcolemma. Purification and properties of plasma membranes from the rat uterus. 22 28

As in rats, administration of estradiol to ovariectomized mice results in a trypsin-like proteolytic activity in the uterus. After fractionation of uteri from estradiol-treated ovariectomized mice the protease activity was found in the 12,000 times g pellet and the nucleus, appearing first in the former. Further fractionation of the pellet by discontinuous sucrose gradient centrigugation resulted in sedimentation of the protease with 5'-nucleotidase, a marker enzyme for plasma membrane and separate from mitochondrial and lysosomal enzyme markers. Solubilization was best accomplished by lysis at 37 degrees. The soluble enzyme from mouse uterus had optimal activity at about 43 degrees and pH 8.3 and was inhibited by diisopropylfluorophosphate, tosylarginine methyl ester, antipain, and leupeptin, but not by soybean trypsin inhibitor. Inhibition in vitro by antipain and leupeptin, two low molecular weight peptides, prompted the study of their effect in vivo on the mouse uterus. After intact, cycling female mice received subcutaneous injections of antipain and leupeptin for 16 days, their uteri showed significant diminution in weight and total DNA when compared to untreated controls. Fertility rates were also diminished. Trypsin-like protease activity may be essential to normal uterine metabolism and function.
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PMID:Antipain and leupeptin restrict uterine DNA synthesis and function in mice. 26 27

Total protein, RNA and DNA content and the activity of acid and alkaline phosphatases, 5'-nucleotidase and isocitrate dehydrogenase were studied in rat uterus during the first 8 days of pregnancy. Isocitrate dehydrogenase activity showed marked fluctuations from day to day. Nucleotidase and acid phosphatase activities showed a significant increase on day 8. The most marked change in activity was that of alkaline phosphatase which showed a 10-fold increase between days 6 and 8, due largely to an increase in the activity of this enzyme in the decidual nodule. The rise in alkaline phosphatase activity did not occur in rats ovariectomized on days 1, 2 or 4 of pregnancy and was markedly decreased in those ovariectomized on day 6. [3H]-uridine incorporation into RNA showed a significant increase between days 2 and 6 whereas [3H]-thymidine incorporation into DNA showed a significant increase on day 6.
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PMID:Enzymic activity in rat uterus during early pregnancy. 118 35

Extracellular adenosine has the potential to influence many aspects of target cell metabolism. The present study has determined the endogenous levels of adenosine in the pregnant mouse uterus and developing embryo-decidual unit with respect to the expression of two key enzymes of adenosine metabolism, 5'-nucleotidase (5'-NT; EC 3.1.3.5) and adenosine deaminase (ADA; EC 3.5.4.4). To measure adenosine levels, nucleoside extracts were etheno-derivatized and quantitated by high-performance liquid chromatography-fluorescence detection (0.03 pmol/mg protein sensitivity). Adenosine levels were determined to be 0.18 nmol/mg protein in the nonpregnant uterus; however, two statistically significant changes were identified in the pregnant uterus: (1) a periimplantation surge between day 3 (0.24 nmol/mg protein) and day 5 (0.59 nmol/mg protein) of gestation (plug day 0; implantation day 4); and (2) an early postimplantation decline between day 6 (0.54 nmol/mg protein) and day 7 (0.10 nmol/mg protein). The periimplantation adenosine surge coincided with uterine expression of 5'-NT, an enzyme which catalyzes the irreversible dephosphorylation of 5'-AMP to adenosine. 5'-NT expression was shown by Northern blot analysis to peak in the embryo-decidual unit on day 5 of gestation and then to decline through day 9; transcripts remained elevated in the placenta between day 9 and day 13 (the latest day examined in this study). By use of specific enzyme histochemistry, most 5'-NT activity was localized to the primary decidual zone on day 5. This expression subsequently declined during regression of the primary decidua; however, 5'-NT appeared on giant trophoblast (days 7-13) and the metrial gland (days 11-13). Other purine catabolic enzymes degrading AMP (adenylate deaminase) or generating adenosine (S-adenosylhomocysteine hydrolase) were not detected in the embryo-decidual unit suggesting that the net flux of utero-placental AMP catabolism proceeds with adenosine as an intermediate, this being the major pathway of adenosine formation. The sharp drop in adenosine levels between day 6 and day 7 coincided with a rise in the activity and mRNA expression of ADA, an enzyme which catalyzes the irreversible deamination of adenosine to inosine. ADA was previously localized to the secondary decidual zone (days 6-11), secondary giant cells (days 7-13), and spongiotrophoblasts (days 8-13) in the mouse (Knudsen et al., 1991). Results of developmental Northern blot analysis demonstrated a direct correlation of relative 5'-NT/ADA mRNA band intensity to adenosine content between day 4 and day 9 of gestation, suggesting that the local availability of adenosine in the antimesometrium is dependent upon the distribution of these enzymatic activities.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Adenosine levels in the postimplantation mouse uterus: quantitation by HPLC-fluorometric detection and spatiotemporal regulation by 5'-nucleotidase and adenosine deaminase. 142 25

An estrogen-regulated arginine esteropeptidase is present in the immature rat uterus. The enzymatic complex consists of a membrane-bound activator and a soluble proenzyme. The activator is under strong estrogen control; its activity increases 10-fold 3 h after a single dose of 17 beta-estradiol. The subcellular localization of the activator is determined by a radioactive assay of fractions prepared by sucrose density centrifugation. The distribution of activity parallels the distribution of two plasma membrane markers, Mg2+-ATPase and 5'-nucleotidase. Electron micrographic visualization of the gradient fractions containing the activator reveals a population of vesicles 0.2-0.5 micron in diameter.
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PMID:Estradiol stimulates a uterine plasma membrane protease activator. 296 50

Uterine plasma membrane preparations were obtained by centrifugation on discontinuous sucrose gradients. The specific activity of the plasma membrane marker 5'-nucleotidase was increased 10-fold while the specific activity of glucose-6-phosphatase was increased 3-fold. Electron microscopy showed mainly closed vesicles having diameters mainly in the range of 0.1 to 0.4 micron and an absence of other recognizable organelles such as mitochondria. D-Glucose transport was inhibited by sulfhydryl reagents, phloretin, and cytochalasin B. Uptake was prevented at high osmotic pressures. The Km of glucose transport was 12.2 +/- 1.1 mM. Studies of the inhibition of [3H]cytochalasin B binding by D-glucose indicated that the value of the Kd of the cytochalasin B-transporter complex was larger than 1 microM. These data demonstrate the potential usefulness of these preparations in the study of glucose transport in rat uterus and its control by steroid hormones.
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PMID:Glucose transport by uterine plasma membranes. 403 86

Changes in the activity of 5'-nucleotidase, the marker enzyme of plasma membranes, in membrane cells of the uterus and liver were examined upon action of tropic and nontropic steroid hormones. In case of tropic steroids, the curves of changes in the activity with rise in the hormone concentration are complicated and broken with a marked minimum at 10(-8) M. Upon the action of nontropic hormones there takes place a monotonous rise in the enzymatic activity. The characteristic differences as shown by the curves make it possible to apply 5'-nucleotidase as endogenous probe during studies into hormone-membrane interactions.
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PMID:[5'-Nucleotidase as an "internal probe" in studying steroid hormone interaction with the plasma membranes of target cells]. 629 Feb 62

We have studied the specific binding of 1,3,5(10)-estratrien-2,3,17 beta-triol (2-hydroxyestradiol) to an enriched membrane fraction isolated from the rat anterior pituitary gland. Specific [6,7-(3)H]2-hydroxyestradiol-17 beta ([3H]2-hydroxyestradiol) binding is saturable and displays a high and low affinity binding component. The apparent dissociation constants, KD, are 4 +/- 2 x 10(-10) and 2 x 10(-6) M with 13 fmol and 2.6 pmol bound/mg of protein, respectively. The specific high affinity binding increases linearly with increasing amounts of tissue protein. The binding is both temperature- and pH-dependent, with maximal binding at 37 degrees C and pH 7.4. The 2-hydroxyestradiol binding is shown to be stereospecific. Dopamine and spiroperidol (a dopamine antagonist) competitively inhibit the specific binding of [3H]2-hydroxyestradiol to the high affinity binding site with inhibition constants, KI, of 1 x 10(-6) M and 2 x 10(-5) M, respectively. Related catecholestrogens (2-hydroxyestrone and 2-hydroxyestriol) are also competitive inhibitors of [3H]2-hydroxyestradiol binding with KI values of 1.5 x 10(-5) M and 1.9 x 10(-5) M, respectively. None of the estrogens (estrone, estradiol, estriol) or 2-methoxyestrogen derivatives (2-methoxyestrone, 2-methoxyestradiol, 2-methoxyestriol) inhibits [3H]2-hydroxyestradiol binding at concentrations up to 10(-4) M. Norepinephrine, epinephrine, and serotonin are also ineffective as inhibitors at concentrations of 10(-5) M and inhibited less than 20% at 10(-4) M. Centrifugation through a stepwise discontinuous sucrose density gradient is used to separate subcellular components of the anterior pituitary cells. Approximately 90 per cent of the specific [3H]2-hydroxyestradiol binding is associated with the material at the 47.4 to 52.9% sucrose interface, the layer most highly enriched for 5'-nucleotidase (an enzyme marker for plasma membranes). Studies of tissue specificity indicate that specific 2-hydroxyestradiol binding sites are heterogeneously distributed in nervous tissue with the highest concentration of binding sites in the anterior pituitary, cerebral cortex, and hypothalamus and lower levels found in the thalamus and striatum. Low levels 2-hydroxyestradiol binding sites are also identified in liver and uterus. The present demonstration of specific 2-hydroxyestradiol binding to the anterior pituitary membrane provides information on the mechanism of catecholestrogen action.
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PMID:Binding of 2-hydroxyestradiol to rat anterior pituitary cell membranes. 743 Jan 5


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