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:3.1.3.9 (glucose-6-phosphatase)
3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence of ATPase activity was demonstrated in isolated nuclei of human spermatozoa by high resolution cytochemical methods. The Wachstein and Meisell technique as modified by Marchesi and Palade was used. ATPase activity was identified as dense and irregularly distributed granules confined to the exposed surface of spermatozoa nuclei. Within the nucleus the reaction product appeared as electron dense precipitates randomly distributed. Control experiments were negative. Deposits of lead phosphate specifically restricted to the exposed surface of nuclei were interpreted as an indication of a glucose-6-phosphatase and/or phosphohydrolase activity. Whether this activity is located in remnants of the inner leaflet of the nuclear envelope is not known. The presence of the enzyme activity within the nucleus is thought to be related to aerobic ATP synthesis previously suggested. If so, this function may be involved in establishing and/or maintaining the highly complex structural organization of spermatozoa nuclei.
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PMID:Distribution of ATPase in isolated human spermatozoa nuclei: a high resolution cytochemical study. 4 Sep 6

The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze-drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ. Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone. The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation. The order of sensitivity to aldehyde fixation of the enzymes tested was glucose-6-phosphatase greater than thiamine pyrophosphatase greater than 5'-nucleotidase greater than adenosine triphosphatase greater than acid phosphatase. Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde. Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G-6-Pase, TPPase, and 5'-nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase. Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G-6-Pase, TPPase, and 5'-nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual. Quenching with subsequent freeze-drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.
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PMID:Effect of fixation on demonstration of phosphatases of Eimeria tenella grown in chick kidney cell cultures. 6 Dec 71

Sorbitol density gradient centrifugation applied to intestinal mucosa homogenates resulted in a complete separation of soluble calcium-binding protein from the bound fraction of calcium-binding protein, providing further documentation of the bound pool of calcium-binding protein. The peak of the bound calcium-binding protein was not associated with the major peaks of any of the markers used, but was associated with minor peaks of alkaline phosphatase, RNA, and glucose-6-phosphatase. Lack of association of bound calcium-binding protein with (Na+ + K+)-ATPase indicated that the bound calcium-binding protein is not on the basolateral membrane. Differential centrifugation fractionation indicated that the bound calcium-binding protein is not associated with nuclei or mitochondria. The bound calcium-binding protein also could not be detected in partially purified brush borders. Exclusion of the brush border and basolateral membranes as the location of the bound calcium-binding protein suggests an intracellular locale.
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PMID:Studies on the subcellular localization of the membrane-bound fraction of intestinal calcium-binding protein. 11 17

A permanent cell line (HLC-1) was established from the pleural effusion of a human lung adenocarcinoma. The cell line was characterized by the monolayered and multilayered organoid growth of epithelioid cells with the doubleing time of about 33 hr and the modal chromosome number of 68. Cloning efficiency was 17.9% in liquid medium and 8.3% in soft agar. The cell produced a large amount of epithelial mucin. Electron microscopic examination revealed many secretory granules and terminal bars. They formed spherical aggregates in a gyratory culture which showed adenocarcinoma-like tubular structures histologically. Enzyme-histolochemically, they showed the characteristics of lung adenocarcinoma cells except for a few enzymes such as glucose-6-phosphatase and ATPase. Heterotransplantation of the cells produced the tumor. These characteristics confirm that HLC-1 cell line is a human lung adenocarcinoma cell line.
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PMID:Establishment and characteristics of a human lung adenocarcinoma cell line. 14 93

Plasma membranes isolated from Yoshida ascites hepatoma AH-130 by a modification of the method of T.K. Ray (Biochim. Biophys. Acta 196:1, 1970), were subfractionated into three fractions having densities (d) 1.12, 1.14 and 1.16 by discontinuous sucrose density-gradient. Membrane subfractions were characterized by electron-microscopy, by assay of marker enzymes and by lipid composition. All subfractions appeared to be essentially free from whole mitochondria, lysosomes and nuclei. Subfraction d 1.16 had the highest 5'-nucleotidase, Mg++-ATPase and (Na+ +K+)-ATPase activities; cytochrome c oxidase was undetectable in any fraction and glucose-6-phosphatase was measurable only in fraction d 1.14 and 1.16. Cyclic AMP phosphodiesterase was nearly equally distributed in the fractions. Adenylate cyclase, 5'-nucleotidase and Mg++-ATPase activities of tumor membrane were lower with respect to liver plasma membrane, while cyclic AMP phosphodiesterase and (Na" +K+)-ATPase were found to have similar activities in the two membrane preparations. With respect to liver membrane, hepatoma membrane contained a higher amount of glycolipids and a higher amount of phospholipids accounted for mainly by sphingomyelin, phosphatidylserine and phosphatidic acid. The possible significance of the decrease of adenylate activity in the hepatoma membrane is briefly discussed.
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PMID:Isolation and characterization of the plasma membrane from Yoshida hepatoma cells. 16 55

Plasma membranes were isolated from rat liver mainly under isotonic conditions. As marker enzymes for the plasma membrane, 5'-nucleotidase and (Na+ + K+)-ATPase were used. The yield of plasma membrane was 0.6-0.9 mg protein per g wet weight of liver. The recovery of 5'-nucleotidase and (Na+ +K+)-ATPase activity was 18 and 48% of the total activity of the whole-liver homogenate, respectively. Judged from the activity of glucose-6-phosphatase and succinate dehydrogenase in the plasma membrane, and from the electron microscopic observation of it, the contamination by microsomes and mitochondria was very low. A further homogenization of the plasma membrane yielded two fractions, the light and heavy fractions, in a discontinuous sucrose gradient centrifugation. The light fraction showed higher specific activities of 5'-nucleotidase, alkaline phosphatase, (Na+ +K+)-ATPase and Mg2+-ATPase, whereas the heavy one showed a higher specific activity of adenylate cyclase. Ligation of the bile duct for 48 h decreased the specific activities of (Na2+ +K+)-ATPase and Mg2+-ATPase in the light fraction, whereas it had no significant influence on the activities of these enzymes in the heavy fraction. The specific activity of alkaline phosphate was elevated in both fractions by the obstruction of the bile flow. Electron microscopy on sections of the plasma membrane subfractions showed that the light fraction consisted of vesicles of various sizes and that the heavy fractions contained membrane sheets and paired membrane strips connected by junctional complexes, as well as vesicles. The origin of these two fractions is discussed and it is suggested that the light fraction was derived from the bile front of the liver cell surface and the heavy one contained the blood front and the lateral surface of it.
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PMID:Subfractionation of rat liver plasma membrane. Uneven distribution of plasma membrane-bound enzymes on the liver cell surface. 17 48

Localization and activities of alkaline phosphatase, ATPase, 5-nucleotidase, glucose-6-phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase were studied in the miracidium of Fasciola hepatica L. Except for nucleoside diphosphatase whose activity in the miracidium was not observed, all the enzymes were most active in the archenteron, protonephridia and nerve ganglion. This localization of the reaction intensity allows the inference that the three organs mentioned are sites of both intense carbohydrate metabolism and lively active transport. The role of phosphatases in carbohydrate metabolism is discussed.
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PMID:Specific and non-specific phosphatases in the miracidium of Fasciola hepatica L. 17 37

Nuclei, nuclear membranes and rough endoplasmic reticulum (rER) were isolated from onion root tips and stems. Structural preservation and purity of the fractions was determined by electron microscopic and biochemical methods. Gross compositional data (protein, phospholipid, nonpolar lipids, sterols, RNA, DNA), phospholipid and fatty acid patterns, enzyme activities (ATPases, ADPase, IDPase, glucose-6-phosphatase, 5'-nucleotidase, acid phosphatase, and NADH- and NADPH-cytochrome C reductases), and cytochrome contents were determined. A stable, high salt-resistant attachment of some DNA with the nuclear membrane was observed as well as the association of some RNA with high salt-treated nuclear and rER membranes. The phospholipid pattern was identical for both nuclear and rER membranes and showed a predominance of lecithin (about 60%) and phosphatidyl ethanolamine (20-24%). Special care was necessary to minimize lipid degradation by phospholipases during isolations. Nonpolar lipids, mostly sterols and triglycerides, accounted for 35-45% of the membrane lipids. Sterol contents were relatively high in both membrane fractions (molar ratios of sterols to phospholipids ranged from 0.12 to 0.43). Sitosterol accounted for about 80% of the total sterols. Palmitic, oleic, and linoleic acids were the most prevalent acids in membrane-bound lipids as well as in storage lipids and occurred in similar proportions in phospholipids, triglycerides and free fatty acids of the membrane. About 80% of the fatty acids in membrane phospholipids and triglycerides were unsaturated. A cytochrome of the b5 type was characterized in these membranes, but P-450-like cytochromes could not be detected. Both NADH and NADPH-cytochrome c reductases were found in nuclear and rER membranes and appeared to be enriched in rER membranes. Among the phosphatases, Mg2+-ATPase and, to lesser extents, ADPase, IDPase and acid phosphatase activities occurred in the fractions, but significant amounts of monovalent ion-stimulated ATPase, 5'-nucleotidase and glucose-6-phosphatase activities did not. The results obtained emphasize that the close biochemical similarities noted between rER and nuclear membranes of animal cells extend to these fractions from plant cells.
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PMID:Characterization of nuclear membranes and endoplasmic reticulum isolated from plant tissue. 17 22

Female rats were injected subcutaneously with ethionine, and enzymic activities of liver membranes (Na+-k+-stimulated ATPase, Mg2+-stimulated ATPase, glucose-6-phosphatase, NADPH: cytochrome c oxido-reductase and NAD-nucleosidase) examined at proper intervals, during the intraperitoneal treatment of an egg phospholipid preparation (EPL). It is shown that EPL is unable to overcome the enzymic changes due to severe ethionine treatment, but is able to facilitate the recovery times after drug withdrawal for all the enzymic activities, except for NAD-nucleosidase. At lower dosage of the drug, the ethionine treatment is able to prevent the observed change of the glucose-6-phosphatase activity but not that of the Mg2+-ATPase. It is suggested that the EPL treatment may modify the chemical composition ahd/or architecture of liver membranes, altered by the ethionine injection, thus acting, at least partially, on the enzymic changes.
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PMID:The effect of egg phospholipid administration upon liver enzymic activities during ethionine treatment. 18 Dec 70

A primary objective of the present study has been to determine the changes which occur in Rana catesbeiana liver organelle membranes during thyroxine-induced metamorphosis. To this end, enzyme and cytochrome profiles were determined for mitochondria, microsomes, and nuclear membrane fractions isolated from livers of R. catesbeiana tadpoles which had been fasted for 6 days at 15 +/- 0.5 degrees and then immersed in thyroxine, 2.6 X 10(-8) M, for periods of up to 12 days at 23.5 +/- 0.4 degrees. The ratio of total succinate-cytochrome c reductase activity in the initial homogenate fraction to the total activity of this mitochondrial "marker" enzyme recovered in the final mitochondrial fraction remained constant, approximately 0.5, throughout the course of thyroxine treatment; however, after a 3- to 4-day latency the mitochondrial protein mass recovered per unit mass of initial homogenate protein was found to increase significantly (approximately 2-fold by Day 10 of thyroxine treatment). A similar increase was also observed in the yield of microsomal, but not nuclear membrane, protein mass as a function of thyroxine treatment. Prolonged thyroxine treatment (12 days) resulted in approximately 50% decreases in tadpole liver homogenate and microsomal NADH-cytochrome c reductase specific activities; in contrast, mitochondrial and nuclear membrane NADH-cytochrome c reductase specific activities were not altered under the same conditions. In addition, homogenate and microsomal NADPH-cytochrome c reductase specific activities were found to have increased significantly after 12 days of thyroxine treatment; however, the specific activity of NADPH-cytochrome c reductase in the mitochondrial fraction was unchanged. It was also observed that thyroxine treatment resulted in increases in homogenate and microsomal glucose-6-phosphatase specific activities, whereas the mitochondrial as well as nuclear membrane glucose-6-phosphatase specific activities remained unchanged. Furthermore, in contrast to homogenate and mitochondrial monoamine oxidase specific activities, which decreased 30 and 40%, respectively, as a consequence of thyroxine treatment (12 days), the succinate-cytochrome c reductase and oligomycin-sensitive Mg2+ ATPase specific activities determined for these fractions increased significantly. In all instances, changes as a result of thyroxine treatment in membrane-localized homogenate or organelle enzyme specific activities were apparent only after a 3- to 4-day initial latent period. The in vitro effects of thyroxine (10(-10) - 10(-5) M) on the membrane-localized enzyme activities examined in this study were either negligible or, as in the case of mitochondrial succinate-cytochrome c reductase and microsomal NADH-cytochrome c reductase, opposite to the changes observed in response to in vivo thyroxine treatment, with the exception of microsomal NADPH-cytochrome c reductase activity which was enhanced approximately 2-fold by 10(-5) M thyroxine...
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PMID:Alterations in enzyme and cytochrome profiles of Rana catesbeiana liver organelles during thyroxine-induced metamorphosis. Changes in membrane-localized phosphohydrolases, oxidoreductases, and cytochrome levels in response to in vivo thyroxine administration. 18 3


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