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:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipase activity extracted from cultured neonatal rat heart cells was characterized and identified as lipoprotein lipase. Enzyme activity was stimulated by human apoC-II and rat serum; serum stimulation was prevented by human apoC-I and by apoC-II. Lipolysis was maximal at pH 8.0 and was inhibited by protamine sulfate, NaCl, and high concentrations of heparin. About 50% of heart cell lipase activity applied to heparin-Sepharose bound to the gel and was eluted with a NaCl gradient. A peak of lipase activity was observed at 0.84 M NaCl. Neonatal rat heart cells in culture are a mixture of muscle and non-muscle cells. To determine the cellular location of the lipoprotein lipase, enzyme activity and muscle cell content of the cultures were determined. Myosin ATPase was used as an index of muscle cell content since ATPase specific activity correlated (r = +0.97) with muscle cell content determined immunofluorescently. When muscle cell content of cultures was decreased or increased by differential plating, lipase specific activity was constant. Moreover, lipase specific activity was constant during culture growth despite a decrease in muscle cell content. It was concluded that lipoprotein lipase activity of cultured heart cells is not associated solely with either muscle or non-muslce cells.
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PMID:Lipoprotein lipase in cultured heart cells: characteristics and cellular location. 13 38

Ethanol and other alcohols stimulate adenylate cyclase activity in various tissues and potentiate its stimulation by some hormones. This effect, however, usually requires a high alcohol concentration. In some cases, an unknown substance, different from cyclic AMP, was formed from ATP in the presence of an alcohol and mimicked stimulation of adenylate cyclase. Ethanol inhibits phosphodiesterase activity in some tissues. In the brain, only the low affinity enzyme of pons-medulla region is inhibited. ATP levels and ATPase activities are affected by ethanol treatment and this can lead to secondary changes of the cyclic AMP levels. Cyclic AMP levels in the brain and liver are decreased by acute ethanol administration while levels in other organs are unchanged. High doses of ethanol inhibit the postdecapitation-induced rise of cyclic AMP level in the brain while low ethanol doses potentiate the postdecapitation rise of cyclic AMP in the lower brain stem. Chronic ethanol administration increases basal adenylate cyclase activity and cyclic AMP levels, and decreases stimulation of adenylate cyclase by norepinephrine in the brain. In contrast, the stimulation of cyclic AMP formation by norepinephrine and other biogenic amines is increased in the brain of ethanol-withdrawn animals. Chronic administration of ethanol affects also cyclic AMP levels and cyclic AMP formation in some peripheral organs. Cyclic AMP might be involved in ethanol-induced fatty liver, since it activates hepatic lipase and might also participate in the fatty acid oxidation.
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PMID:Interactions of ethanol with cyclic AMP. 16 56

The intestinal epithelium of Ascardia galli has been studied with various cytological and cytochemical techniques. It consists of large epithelial cells resting on a thick collagenous basal lamina. Their luminal surface is provided with microvilli. The intestinal cells store considerable amounts of glycogen and neutral lipids. Some intracellular granular inclusions, which stain for proteins, phospholipids and lipoproteins, are distributed throughout the cytoplasm. The brush border is composed of microvilli whereas the outer surface coat consists of saliva resistant PAS-positive material. The detailed histochemical analysis of surface material has revealed that it is composed of nonacetylated acid mucopolysaccharides rich in hyaluronic acid with carboxylate polyanions. The brush border shows intense activities of acid phosphatase and glucose-6-phosphatase, moderate of ATPase, and lipase, weak of 5'-nucleotidase. Acid phosphatase-positive intracellular structures are seen in the intestinal epithelium which form distinct aggregations.
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PMID:Morphological and histochemical observations on the intestinal epithelium of Ascardia galli (Nematoda: Ascaridida). 21 46

With histochemical methods the distribution of some enzymes and metabolic substances in the epidermal peelings of Phaseolus mungo, Lathyrus sativus, and Opuntia elatior under light and dark conditions is examined. Dehydrogenases oxidases, transferases and hydrolases were studied. Fluctuations in the activity of hydrolases, especially, acid phosphatase, lipase, glucose-6-phosphatase, adenosine triphosphatase, dehydrogenases and transferases were observed during light and dark conditions. The role of such fluctuations in relation to stomatal regulation is discussed. Based on the present studies the following is suggested; stomatal opening and closing is related to structural and metabolic changes, and these changes are brought about by sugar gradients in the guard cells; light is enhancing the synthesis of sugars and some hormones, and besides this it stimulates membrane bound adenyl cyclase and release of cyclic AMP which affects the permeability; subsidiary cells actively participate in the stomatal physiology. Lysosomal hydrolytic enzymes like acid phosphatase are actively involved in catabolic phase of normal guard cells metabolism and regulate the osmotic pressure of the guard cells.
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PMID:Histochemical studies in stomatal apparatus of Phaseolus mungo Linn, Lathyrus sativus Linn and Opuntia elatior Mill. 59 72

Vanadate stimulated the release of rat hepatic lipase activity from liver slices into an incubation medium in a time- and dose-dependent manner. Insulin, however, failed to have this stimulatory action, and the release by heparin was recognized, but was not additive to that by vanadate. Amiloride, an inhibitor of tyrosine kinase in some receptors and of the Na+/H+ exchange system suppressed the vanadate-stimulated release. Biochanin A, a different type of tyrosine kinase inhibitor than amiloride, also suppressed the effect of vanadate. The stimulation by vanadate was clearly preserved in Na(+)-, K(+)-, or Ca(2+)-free medium, suggesting that neither the Na+/H+ exchange system, Na+, K(+)-adenosine triphosphatase, nor Ca(2+)-influx into cells is involved in the action of this substance. These results suggest that vanadate-stimulated release of the enzyme activity is associated with the activation of the tyrosine kinase activity.
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PMID:Vanadate-stimulated release of hepatic lipase activity from liver. 181 20

1. The origin of the limiting membranes of autophagic vacuoles (AVs) in mouse pancreatic acinar cells was studied in vinblastine-induced autophagocytosis. 2. The marker enzymes used were adenosine triphosphatase, lipase, inosine diphosphatase and thiamine pyrophosphatase. The following impregnation techniques were used: unbuffered osmium tetroxide impregnation, imidazole-buffered osmium tetroxide impregnation and uranyl-lead-copper impregnation. 3. Only a weak lipase activity was observed between the limiting membranes of a few AVs. The AV membranes were stained heavily with all impregnation techniques used. 4. The origin of AV membranes seems to be same in mouse liver and exocrine pancreas in vinblastine-induced autophagocytosis.
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PMID:Cytochemical studies on induced autophagocytosis in mouse exocrine pancreas. 245 89

Delipidation of beef heart electron transport particles with phospholipase A2 has been examined. When the particles were treated with the lipase and subjected to a low bovine serum albumin wash, ATPase activity was unaffected as was the lipid/protein ratio of the particles. However, energisation by ATP/Mg2+ was abolished. Furthermore, unsaturated but not saturated fatty acids discharged the steady-state ATP-driven membrane potential of control samples. When the phospholipase A2 hydrolysis products were removed, inhibition of energy-linked reactions in the lipid-depleted particles was still observed and was interpreted in terms of non-specific leaks in the vesicle membranes, and 'specific' leaks through impaired H+-ATPase complexes. ATPase activity was less susceptible to delipidation than energisation but was, nevertheless, strongly inhibited at 50 percent lipid depletion. Spin label studies indicated a decrease in the fluidity of particle membranes accompanying delipidation. Moreover, the discontinuity seen in Arrhenius plots of ATPase activity was shifted from 17 degrees C (control) to 22 degrees C at 50 percent phospholipid depletion. The data are consistent with a release of unsaturated fatty acids by phospholipase A2 rendering the transport particles both leakier and the membranes less fluid than controls.
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PMID:Effects of delipidation on proton translocation and ATPase activity in beef heart electron transport particles. 288 57

Fetuses were decapitated in one uterine horn in each of 14 sows at 45 d of gestation. Control (C) and decapitated (D) fetuses were removed by Caesarean section from three sows at 65 d of gestation (total of 10 D and 10 C fetuses), two sows at 85 d (six D and six C fetuses) and nine sows at 110 d (nine C and nine D fetuses) of gestation (Exp. 1). In Exp. 2, four to six fetuses were removed from each of two Ossabaw (O) gilts and three crossbred (C, Landrace X Yorkshire) gilts at 70 d of gestation, from three C and O gilts at 90 d of gestation and from three C and two O gilts at 110 d of gestation. In Exp. 1, one semitendinosis muscle was removed for histochemistry, whereas the contralateral muscle was removed and weighed. A medial portion of biceps femoris muscle was removed and used for histochemistry in Exp. 2. In both experiments, transverse sections (cryostat) of muscle were stained for lipid, glycogen (PAS) and the following enzymes: acid ATPase, NADH-TR, NADPH-TR, malate dehydrogenase (NAD- and NADP-dependent reactions; MDH), succinate dehydrogenase (SDH), alpha-glycerol phosphate dehydrogenase (with and without NAD; alpha-GPDH), isocitrate dehydrogenase (NAD dependent; ICDH), esterase, lipoprotein lipase and lipase. In Exp. 1, body and muscle weights of the two groups were not significantly different (P greater than .05) at 65 d of gestation, whereas D fetuses were smaller and had lighter weight muscles (P less than .05) at 85 d of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enzyme histochemical studies in an ontogeny study of muscle development in Ossabaw and decapitated fetuses: cellular reactions. 401 46

1. The existence of phospholipase and lipase activities in the isolated cell envelopes of baker's yeast was demonstrated. 2. The content of phospholipase was found to be markedly higher than that of lipase. 3. After partial enzymic digestion of the isolated cell envelopes, the bulk of the lipolytic activities was recovered in the sedimentable preparations, which consisted of the fragments of the plasma membrane. 4. During repeated washings, the lipase was completely released from the cell envelopes, as were also the bulk of the lipid components and most of the Mg(2+)-dependent adenosine triphosphatase, an enzyme connected with the plasma membrane. The phospholipase was more firmly bound to the preparation but not so firmly as the external saccharase. 5. These results indicate that the lipolytic enzymes found in the cell envelopes are mostly located in the plasma membrane.
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PMID:The lipolytic activities of the isolated cell envelope fracttions of Baker's yeast. 424 61

Protoplasts of Listeria monocytogenes strain 42 were fractionated after control lysis on a Ficoll (a polysucrose) density gradient. Visually, five zones could be recognized in the gradient. The first one was composed of amorphous cytoplasmic solutes (fraction 1a) and a mixture of particles (fraction 1b). These were: (i) light particles that were lipase-sensitive and composed of six subunits and (ii) heavy particles, sensitive to ribonuclease and devoid of fine structure. The second zone consisted of tubules and vesicles still harboring cytoplasmic components (fraction 2), whereas the third zone contained only empty vesicles and protoplast ghosts (fraction 3). The material congregating into the fourth zone was morphologically identical to that of the third (fraction 3a). The fifth and heaviest zone contained a mixture of (i) particles without any substructure and (ii) partly lysed protoplasts (fraction 4). Fractions 1b and 4 were the richest in nucleic acids (ribonucleic acid, 11.4 and 9.4%, respectively; deoxyribonucleic acid, 5.1 and 4.8%, respectively), whereas fraction 1b had the highest protein contents (74.6%). Phospholipids were mainly found in fractions 2 and 3. Except for fraction 1, all materials contained significant amounts of protein-bound phosphorus. The main concentrations of four enzymes were: glucose-6-phosphate dehydrogenase (fraction 1a); adenosine triphosphatase and reduced nicotinamide adenine diphosphate oxidase (fraction 3); nitro blue tetrazolium chloride reductase (fraction 2). Fractionation of strain 42 after addition of (32)P during the mid-log phase of growth revealed that the radio-activity was mainly detected in fraction 1b, when growth in the presence of the marker was allowed for 10 min, and in fraction 2, when growth was allowed for 90 min. The vesicles of fraction 2, often tubular, are probably of mesosomal origin, whereas those of fraction 3, which are always spherical, represent, most likely, the bulk of the cell plasma membrane. Our data showed slight chemical differences between these two fractions, but the differences in enzymatic activities and lipid-phosphorus incorporation during long pulse experiments were most dramatic.
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PMID:Fractionation and characterization of the plasma and mesosome membrane of Listeria monocytogenes. 430 41


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