Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seminal plasma from 22 men attending an infertility clinic was subjected to preparative ultracentrifugation for 2 h at 105,000 g. The pelleted material as well as the supernatant thus obtained were investigated with regard to prostasome membrane-linked enzyme activities in relation to other semen parameters. The mean activity of Zn2+-dependent adenosine triphosphatase in the sedimented prostasome fraction was 1.45 +/- 1.02 mumol (range 0.29-4.79) orthophosphate released per milligram protein and 20 min, while the corresponding figures for the supernatant were 0.56 +/- 0.30 (range 0.12-1.29). Hence, 72% of the specific activity was sedimented, and 28% remained in the supernatant. The same pattern was recognized with regard to the other two enzymes investigated, although they displayed individual characteristics with regard to distribution after ultracentrifugation. The pelleted prostasome-linked mean aminopeptidase activity was 0.39 U/mg protein (81.9%), with only 0.087 U (18.1%) remaining in the supernatant. The corresponding figures for gamma-glutamyltransferase were 7.89 (60.4%) and 5.17 (39.6%) mu kat/g protein, respectively. The different enzyme activities in the prostasome fraction and supernatant, respectively, were interrelated to each other and correlated significantly with r values between 0.73 and 0.93 (p less than 0.001). It was concluded that a minor fraction of prostasomes remained in the supernatant after ultracentrifugation. A relationship existed between prostasomes and semen volume revealing a rather consistent pattern in that small volumes favoured the presence of comparatively more prostasomes in the supernatant and less prostasomes in the pelleted fraction than large volumes. In addition, the sperm concentration seemed to be another determinant of the distribution of prostasomes in seminal plasma on subsequent ultracentrifugation.
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PMID:Prostasome membrane associated enzyme activities and semen parameters in men attending an infertility clinic. 290 7

The effect of a single administration of lead nitrate on the activity of gamma-glutamyltranspeptidase (gamma-GT), adenosine triphosphatase (ATPase), the placental form of glutathione S-transferase (GST-P) and adenylate cyclase (AC), four enzymes widely used as phenotypic markers for preneoplasia, was investigated in the liver of male Wistar rats. The results of the histochemical enzymatic staining indicated that an acute treatment with lead nitrate induces the activity of gamma-GT, mainly in the hepatocytes located around zone I of the liver acinus, with a maximum seen between 72-96 hours. On the other hand, the activity of ATPase was found to be severely inhibited at 2-3 days after treatment, as shown by a strong decrease in the staining of the bile canaliculi of zones II and III. Immunohistochemical analysis revealed that lead nitrate administration also resulted in the appearance in most of the hepatocytes of GST-P, an enzyme whose activity is almost undetectable in normal rat liver, but is elevated in preneoplastic liver lesions. Finally, lead nitrate treatment resulted in an inhibition of AC activity which was maximal after 24 hours.
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PMID:Modulation of the activity of hepatic gamma-glutamyl transpeptidase, adenosine triphosphatase, placental glutathione S-transferase and adenylate cyclase by acute administration of lead nitrate. 290 38

Three enzyme makers, glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase, have been used in studying carcinogenesis of hepatocellular carcinoma. They have been investigated in animal models and human hepatocellular carcinoma in vivo and in vitro. But the inconsistent levels of these three enzymes associated with this type of carcinoma raised the possibility that the carcinoma cells might have derived from the cells originating from different stages of differentiation. To evaluate this possibility, three human cell lines, Hep G2, Hep 3B, and HA 22T, all thought to be arrested in different stages of differentiation based on their biochemical and morphological characteristics, were used as models. The three enzyme markers glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase were examined cytochemically and biochemically. Our results showed that there was no correlation between the ATPase levels and the stages of the cell line's differentiation. But both glucose-6-phosphatase and gamma-glutamyl-transpeptidase were higher in cells that were more differentiated.
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PMID:Cytochemical localization and biochemical analysis of the enzyme markers in human hepatoma cell lines. 290 58

The potential of X-rays to induce preneoplastic lesions in the rat liver was studied in order to clarify the reason why X-rays are ineffective in inducing hepatocellular carcinoma in this animal. Male newborn rats at 8 or 22 days of age received whole body X-ray irradiation of 100 to 400 rads. After weaning they were fed either basal diet or a diet containing 0.05% phenobarbital as a promoter. X-rays induced numerous adenosine triphosphatase-deficient islands appearing in the liver by wk 22 of age. However, they were generally small, gamma-glutamyl transpeptidase-negative, and did not clearly respond to the promoting stimulus of phenobarbital. No hepatic tumors were observed by 22 mo after radiation, even in phenobarbital-treated animals. Thus the X-ray-induced enzyme-altered islands differ somewhat qualitatively from those induced by potent hepatic carcinogens and their preneoplastic potential if at all present may be very low. Similarities between these X-ray-induced lesions and some types of spontaneous enzyme-altered islands are pointed out.
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PMID:Induction by X-irradiation of adenosine triphosphatase-deficient islands in the rat liver and their characterization. 293 43

Recent subcellular fractionation studies have raised the possibility that Na+-K+-ATPase might be present in both the apical and the basal-lateral membranes of exocrine gland acinar cells. Analytical fractionation and immunofluorescence microscopy studies of rat parotid glands were performed to confirm this interpretation. The distributions of biochemical markers after analyses based on differential sedimentation, equilibrium density-gradient centrifugation, and partitioning in an aqueous polymer two-phase system defined a total of 15 physically and biochemically distinct membrane populations. Among these populations, it was possible to select one (designated population i) with the characteristics expected of acinar cell basal-lateral plasma membranes. It contained Na+-K+-ATPase enriched 33-fold, and gamma-glutamyl transpeptidase enriched 23-fold with respect to the initial homogenate. A second population (designated population c) had the characteristics expected of acinar cell apical plasma membranes; it contained Na+-K+-ATPase enriched 28-fold, and gamma-glutamyl transpeptidase enriched 53-fold with respect to the initial homogenate. Although the identification of population c remains provisional, immunofluorescence studies verified that Na+-K+-ATPase is present in both the apical and the basal-lateral acinar cell plasma membranes. In view of these results, it is likely that the apical Na+-K+-ATPase would participate in series with basal-lateral sodium- and chloride-entry pathways in driving the secretory electrolyte fluxes.
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PMID:Mapping subcellular distribution of Na+-K+-ATPase in rat parotid gland. 300 5

Rat intestinal microvillus membrane contains at least 24 polypeptides, of which 18 can be solubilized using Triton X-114 at 4 degrees C. Upon phase separation at 32 degrees C, 11 proteins separated nearly completely into the detergent-rich phase, while 9 proteins were found exclusively in the aqueous phase. Enzymes which were uniquely included in the detergent phase were alkaline phosphatase, leucine aminopeptidase, gamma-glutamyl transpeptidase, and Ca2+-Mg2+ ATPase. The proteins which were excluded from the detergent phase and found exclusively in the aqueous phase included the disaccharidases (glucoamylase, sucrase-isomaltase, trehalase, lactase) and the ileal receptor for the intrinsic factor-cobalamin complex. Integral membrane proteins can thus be separated during solubilization into two groups prior to further purification or characterization.
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PMID:Phase separation of rat intestinal brush border membrane proteins using Triton X-114. 301 Jul 62

Highly purified plasma membranes of calf thymocytes were fractionated by means of affinity chromatography on ouabain-Sepharose. By the method used two subfractions were obtained, one eluting freely from the affinity gel (MF1oua) and a second specifically retained by matrix-bound ouabain (MF2oua), with a total recovery of 95 per cent. Fractionation required the binding of matrix-bound ouabain to its plasma membrane receptor, i.e. (Na+ + K+)-ATPase. Increasing the temperature and binding time did not significantly alter the fractionation of plasma membranes into the two subfractions. Both plasma membrane subfractions separated by ouabain-Sepharose were of plasma membrane origin, as revealed by the identical specific activities of several membrane bound enzymes, gamma-glutamyl transpeptidase, alkaline phosphatase and Mg2+-ATPase in unseparated plasma membranes and in both subfractions, and by the identical amounts of the cytoskeletal protein actin in unseparated plasma membranes and subfractions. The plasma membrane subfractions MF1oua and MF2oua showed different structural and functional properties. In SDS-polyacrylamide gel electrophoresis polypeptides of 170, 150, 110, 94, 39, and 30 kDa were several-fold enriched in the adherent fraction, MF2oua. The phospholipid fatty acid composition of the plasma membrane subfractions proved to be different, as well. MF2oua contained significantly higher amounts of saturated fatty acids as compared to MF1oua. The specific activities of (Na+ + K+)-ATPase, Ca2+-ATPase and lysolecithin acyltransferase were highly enriched in the adherent fraction MF2oua, as compared to MF1oua. The data suggest that by the means of affinity chromatography on ouabain-Sepharose plasma membrane domains of the lymphocyte plasma membrane can be isolated, most probably implicated in the initiation of lymphocyte activation.
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PMID:Separation of plasma membrane domains of calf thymocytes by affinity chromatography on ouabain-Sepharose. 303 28

Study of the products secreted by pancreatic ductal cells and analysis of the mechanisms involved in the discharge of these products have been limited by a lack of in vitro models available to experimentally approach this problem. To this aim, this investigation has been designed to determine if a human pancreatic carcinoma cell line of ductal origin (PANC-1) has maintained some of the differentiated characteristics of normal mammalian pancreatic ductal epithelium. Morphological and immunocytochemical studies indicated that, similar to isolated rat pancreatic ducts, the PANC-1 cell line contained (a) intermediate filaments of the epithelial class, (b) a basolateral plasma membrane localization of Na+, K+-ATPase, (c) complete tight junctions based on freeze-fracture analysis, (d) a cuboidal morphology when grown on Type I collagen-coated nitrocellulose filters or isolated amnion basement membrane, and (e) normal ductal epithelial ultrastructural features. Biochemical analysis indicated that, also similar to isolated rat and human pancreatic ducts, the PANC-1 cell line contained (a) gamma-glutamyltranspeptidase, (b) carbonic anhydrase, and (c) Na+, K+-ATPase based on [3H]ouabain binding assays. Comparative studies with other transformed lines indicated that PANC-1 cells have similarities to ductal lines such as MDCK cells but are markedly different from mesenchymally derived lines such as L cells. In addition, as with isolated rat and human ducts, PANC-1 cells synthesize and secrete sulfated proteins with a MW range of approximately 180K to 1 million daltons, with the predominant species being 660K daltons as indicated by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis. These results indicate that the PANC-1 cell line has maintained at least some of the differentiated characteristics of normal pancreatic ductal epithelial cells and may be a useful system for study of ductal secretory products as well as the mechanisms involved in the discharge of these products.
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PMID:Morphological and biochemical characterization of a human pancreatic ductal cell line (PANC-1). 314 17

The relative potency of chemicals as promoting agents in multistage hepatocarcinogenesis has been previously defined as the Promotion Index through calculations of quantitative stereology. The Promotion Index is a function of the total cell population of altered hepatic foci in the liver at any given time and dose of promoting agent. When the Promotion Index was determined as a function of the dose of phenobarbital given in the diet for varying periods of time, a value of 394 was obtained for doses less than 0.01%; at doses between 0.01% and 0.1%, the Promotion Index was found to be 47. These values were obtained by the extrapolation of slopes of the Promotion Indices at various doses and durations of administration of phenobarbital. The volume percentages of the liver occupied by seven possible phenotypes using three different markers (gamma-glutamyltranspeptidase, canalicular ATPase and glucose-6-phosphatase) were relatively constant in distribution for up to one year of phenobarbital administration except at the two highest doses employed, 0.5% and 0.1%, at which a maximal effect of the promoting agent has been obtained. Possible mechanisms for the biphasic relationship of the Promotion Index of phenobarbital with the dose and time of administration are discussed.
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PMID:The effects of dose and duration of administration on the promotion index of phenobarbital in multistage hepatocarcinogenesis in the rat. 317 34

The clonality of chemically induced altered hepatocellular foci was examined in rat liver. Chimeric rats composed of two histologically distinguishable cell lineages were placed on an initiation-promotion protocol for liver cancer induction. This resulted in multiple lesions of altered enzyme expression. These altered hepatocellular foci are generally considered to be initiated sites susceptible to cancer formation. The cellular origins of these lesions were determined by aligning sections demonstrating cell lineage with serial sections stained for altered enzyme expression. Analysis included 110 areas of deficient ATPase (EC 3.6.1.3) activity and 59 glucose-6-phosphatase (EC 3.1.3.9; G-6-Pase) deficient lesions, 744 foci of re-expression of gamma-glutamyl transpeptidase (EC 2.3.2.2; gamma-GT), and decreased glycogen mobilization (187 lesions). Of the 1100 focal enzyme alterations, 1054 were shown to be composed entirely of cells from a single lineage of the two lineages present in the mosaic tissue. Multiple alterations occurred within given lesions. Lesions with up to four phenotypic alterations were found to consist of cells of a single lineage. These results suggest that individual enzyme-altered foci are clonal in origin and that phenotypic heterogeneity within altered hepatocellular foci is due to lesion progression within a clonal population and not to a multicellular derivation.
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PMID:Clonality of preneoplastic liver lesions: histological analysis in chimeric rats. 319 1


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