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)

To determine the mechanism of the maturation of the brush border membrane in intestinal epithelial cells, purification of the plasma membrane from undifferentiated rat crypt cells and of the basal-lateral membrane from villous cells has been performed. The method is based on density perturbation of the mitochondria to selectively disrupt their association with the membrane. With both cell populations, two membrane subfractions displaying the same respective density on sucrose gradient have been obtained with an overall yield of 15--20% and a 10-fold enrichment of the plasma membrane markers 5'-nucleotidase and (Na+ + K+)-dependent, ouabain-sensitive ATPase chosen to follow their purification. The four fractions were constituted by sheets and apparently closed vesicles of various sizes. Each fraction was characterized by a distinct protein composition and different levels of enzyme activities. The cells, used for the preparation of the membranes, were isolated as a villus to crypt gradient. This separation and that of the membranes, led to the conclusion that the (Na+ + K+)-dependent ATPase is localized principally in the plasma membrane of all cells whatever their state of maturation, while 5'-nucleotidase is predominantly located in the basal-lateral membrane of the villous cells and may serve as a specific marker for the purification of this membrane. Finally it has been shown that aminopeptidase, dissacharidases and alkaline phosphatase do not appear simultaneously in the maturation process of the cells, alkaline phosphatase being absent from the crypt cells and aminopeptidase being the first to be synthesized. This enzyme seems to appear in the crypt cells membrane before being integrated into the mature brush border membrane.
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PMID:Plasma membranes from rat intestinal epithelial cells at different stages of maturation. I. Preparation and characterization of plasma membrane subfractions originating from crypt cells and from villous cells. 21 16

The properties of a number of enzyme activities of the superovulated rat ovary have been studied to establish optimal assay conditions and specific assay procedures for each activity. The activities were chosen on the basis of their extensive use in other tissues of the rat as marker enzymes for the major cell organelles. Homogenates of superovulated rat ovaries were subjected to fractionation by differential rate centrifugation, and sedimentation profiles were constructed for each marker enzyme activity. The various subcellular fractions were also monitored by electron microscopy. The enrichment of fractions with particular organelles by electron microscopy, and enrichment of the appropriate organelle marker enzyme activities correlated well. Sedimentation profiles of a number of plasma membrane marker enzymes demonstrated a marked discrepancy between hCG-binding activity, and 5'-nucleotidase-, alkaline phosphatase-, and Mg2+-dependent ATP-ase on the one hand, and basal, hCG-stimulated, and fluoride-stimulated adenylate cyclase activities on the other hand. Fractions enriched in hCG-binding and adenylate cyclase activities were subjected to further fractionation on discontinuous sucrose density gradients. The distributions of the various plasma membrane markers again indicated a partial dissociations between hCG-binding and adenylate cyclase activities of luteinized rat ovaries, suggesting the existence of two distinct major plasma membrane populations, with different buoyant densities, marker enzyme profiles and adenylate cyclase and hormone-binding levels.
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PMID:Interactions of gonadotropins with corpus luteum membranes. I. Properties and distributions of some marker enzyme activities after subcellular fractionation of the superovulated rat ovary. 21 56

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

High-performance liquid chromatography was used to assay serum acid and alkaline phosphatase. Samples were incubated with adenosine-5'-monophosphoric acid (AMP) in a buffer of required pH, 5'-nucleotidase was inhibited with Ni2+ ions, and the phosphatase activity was determined by measuring the concentration of the reaction product, adenosine. The analysis time, after the incubation is terminated, is short (7 min), and the assay is quantitative and reproducible. Complete separation of the reaction product from the substrate and the naturally occurring serum constituents and the high sensitivity of the ultraviolet detection system eliminate some of the problems commonly encountered in spectrophotometric assays.
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PMID:High-performance liquid chromatographic assay for acid and alkaline phosphatase in serum. 23 Oct 44

In 30 patients with histologically verified malignant liver processes, the authors have examined the value of the serum activity of liver lactate dehydrogenase (LDH), alkaline phosphatase and gamma-glutamyltranspeptidase and in a number of patients, 5'-nucleotidase. These values were compared with the findings received from scintigraphy of the liver. Based on the results obtained, the authors have concluded that the activities of the gamma-glutamyltranspeptidase (gammaGT), 5'-nucleotidase and liver lactate dehydrogenase are more significantly increased in malignant processes of the liver than scintigraphy of the liver could register.
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PMID:Comparative investigations of some enzymatic parameters and liver scanning in the early detection of the malignant liver process. 23 1

An attempt has been made to show that the increase in enzyme activities in sera of pregnant women found with glucose-6-phosphate and adenosine 5'-monophosphate as substrates (described as glucose-6-phosphatase and 5'-nucleotidase) was due to the increase in alkaline phosphatase. The three enzyme activities has pH optima and heat stability characteristics of alkaline phosphatase. The response to the action of inhibitors and activators was typical for alkaline phosphatase. There was an identical increase in all three enzyme activities during pregnancy. As a control similar investigations were made with liver and placental tissue extracts.
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PMID:The serum activity of glucose-6phosphatase and 5'-nucleotidase during human pregnancy. 23 76

The organelle pathology of neutrophils in chronic granulocytic leukaemia (CGL) was investigated by analytical subcellular fractionation. There were minor reductions in activity of some granule enzymes with an abnormal distribution in sucrose density gradients of the specific granules. There was a marked reduction of 5'-nucleotidase activity but this is probably related to the relative reduction of the mononuclear cell contamination of the neutrophils isolated from leukaemic patients compared with controls. Another plasma membrane enzyme, NADH-nitroblue tetrazolium reductase, which has a microbicidal role, had increased activity. Neutrophils from patients with CGL had 13% the alkaline phosphatase activity of controls and were compared with neutrophils from women in the third trimester of pregnancy when the activity was increased to 8 times the control level. The latent activity, per cent inhibition by Levamisole, kinetic constants and subcellular distribution of alkaline phosphatase were similar in the three groups. It is suggested that the properties and intracellular localization of alkaline phosphatase are normal in CGL and that there is a quantitative lack of enzyme.
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PMID:Studies on the subcellular organelles of neutrophils in chronic granulocytic leukaemia with special reference to alkaline phosphatase. 28 20

The UHF fraction from NIL 8 hamster embryo fibroblasts contains the LETS protein and several other major proteins. It exhibits three enzymatic activities in significant amounts: 5'-nucleotidase, alkaline phosphatase, and galactosyl transferase. The latter two appear to be different from the membrane-bound enzymes. This fraction is heavily stained with ruthenium red, a dye specific for the cell coat in intact cells. A comparable fraction from hamster sarcoma virus-transformed cells exhibits a similar overall protein composition but lacks at least three major proteins, including the LETS protein. Compared to NIL 8 cells, the distribution of alkaline phosphatase in fractions from these cells is different, and the level of galactosyl transferase in the UHF is much reduced.
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PMID:Cell surface coat of hamster fibroblasts. 29 62

A new procedure for the purification of plasma membranes of Dictyostelium discoideum is described. Cells are broken by vigorously stirring in the presence of glass beads, and plasma membranes are isolated by equilibrium sucrose density centrifugation. The purified membranes are considerably enriched in alkaline phosphatase and 5'-nucleotidase and contain very low levels of succinate dehydrogenase and NADPH-cytochrome c reductase. The purified membranes contain relatively high levels of phospholipid, sterol and carbohydrate. They appear as a relatively homogeneous population of membrane vesicles in the electron microscope. This new method of purification is compared to previously published procedures which have been found to be unsuitable for our purposes.
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PMID:The purification and characterization of Dictyostelium discoideum plasma membranes. 40 46

A histochemical and autoradiographic study of the lining intestinal epithelium of the snake Xenodon merremii is reported. The absorptive cells present neutral polysaccharides, arginine, tyrosine, tryptophan, cysteine, alkaline phosphatase, acid phosphatase, ATPase, AMPase, esterase and RNA. There are histochemical differences between the goblet cells of the small and of the large intestine. Whereas in the former predominates the neutral polysaccharides and are found arginine, tyrosine, tryptophan and cysteine, in the latter predominates the sulfated polysaccharides (confirmed by the uptake of radioactive sulfur) and no amino acids were found.
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PMID:Histochemical (polysaccharides, proteins, nucleic acids and enzymes) and autoradiographic (incorporation of 35S labelled sodium sulfate) study of the epithelial intestinal cells of Xenodon merremii Wagler, 1824 (Ophidia). 40 42


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