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)

After the repeated injection of sea urchin sperm guanylate cyclase into rabbits, antibodies to the enzyme were formed. These antibodies inhibited the particulate or the Triton-dispersed forms of the sperm enzyme by greater than 97%. The sperm adenylate cyclase, cyclic GMP phosphodiesterase, adenosine triphosphatase, guanosine triphosphatase, and 5'-nucleotidase enzymes were not affected by the antiserum. The antiserum inhibited the Triton-dispersed guanylate cyclase from rat heart, liver, lung, spleen, and kidney but did not inhibit the soluble form of the enzyme from any of these tissues. The inhibition of the Triton-dispersed enzyme in these tissues was partial, however, ranging from 30% (liver) to 70% (heart). These results provide evidence that adenylate cyclase is antigenically different from guanylate cyclase, and that the soluble form of guanylate cyclase is antigenically different from a particulate form of the enzyme in various rat tissues.
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PMID:Sea urchin sperm guanylate cyclase antibody. Cross-reactivity various rat tissue guanylate cyclases. 2 31

Rabbit heart membranes possessing the adenylate cyclase activity were isolated and purified by extraction with high ionic strength solutions and centrifugation in the sucrose density gradient. It was shown that the membranes are characterized by a high percentage of cholesterol (molar ratio cholesterol/phospholipids is 0.24) and an increased activity of Na, K-ATPase, which suggests the localization of adenylate cyclase in the sarcolemma. During centrifugation in the sucrose density gradient the activities of andenylate cyclase and Na,K-ATPase are not separated. Treatment of heart sarcolemma with a 0.3% solution of lubrol WX results in 10--20% solubilization of adenylate cyclase. Purification of the enzyme in the membrane fraction is accompanied by a decrease in the activity of phosphodiesterase; however, about 2% of the heart diesterase total activity cannot be removed from the sarcolemma even after its treatment with 0.3% lubrol WX. Epinephrine and NaF activate adenylate cyclase without changing the pH dependence of the enzyme. The alpha-adrenergic antagonist phentolamine has no effect on the adenylate cyclase activation by catecholamines, glucagon and histamine; the beta-adrenergic antagonist alprenolol competitively inhibits the effects of isoproterenol, epinephrine and norepinephrine, having no effect on the enzyme activation by glucagon and histamine. There is no competition between epinephrine, glucagon and histamine for the binding site of the hormone; however, there may occur a competition between the hormone receptors for the binding to the enzyme. A combined action of several hormones on the membranes results in the averaging of their individual activating effects. When the hormones were added one after another, the extent of adenylate cyclase activation corresponded to that induced by the first hormone; the activation was insensitive to the effect of the second hormone added. It is assumed that the outer membrane of myocardium cells contains a adenylate cyclase and three types of receptors, each being capable to interact with the same form of enzyme. The activity of adenylate cyclase is determined by the type of the receptor, to which it is bound and by the amount of the enzyme-receptor complex.
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PMID:[Isolation, purification and characterization of regulatory properties of adenylate cyclase from rabbit heart]. 2 49

Current information is reviewed on the mechanism of secretion in small intestine, including how it is altered by cyclic 3',5'-adenosine monophosphate and on the structures and properties of cholera and both heat-labile and heat-stable Escherichia coli enterotoxins. Two separate active ion transport processes are altered by cyclic 3',5'-adenosine monophosphate: 1) coupled absorption of NaCl is inhibited in villus cells and 2) active anion secretion is stimulated, probably in crypt cells. Cholera and heat-labile E. coli toxins exert their secretory effect by stimulating intestinal mucosal adenylate cyclase. This stimulation results from the A1 subunit catalyzed transfer of adenosine diphosphate ribose from NAD to a membrane-bound guanosine triphosphatase, thereby inhibiting the enzyme, which normally represses adenylate cyclase. Heat-stable E. coli enterotoxin stimulates intestinal mucosal guanylate cyclase, which appears to be the basis for its enterotoxicity.
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PMID:Mechanisms of action of cholera and Escherichia coli enterotoxins. 3 66

Bilateral occlusion of common carotid arteries in Mongolian gerbils was produced for the periods (up to 15 min) which were shown to be totally reversible. There was an initial increase of cyclic AMP and GABA levels and enhanced activities of adenylate cyclase and glutamate decarboxylase, as well as the reduction of norepinephrine level and decreased activities of monoamine oxidase, GABA-transaminase and Na+-K+-ATPase. Following these changes, decreased concentration of dopamine, serotinin and glutamate were found. The activities of total protein kinase and acetylcholinesterase were found to be reduced after longer periods of short-term ischemia. The data are consistent with the concept of increased non-controled release of putative neurotransmitters in ischemia.
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PMID:Alterations of putative neurotransmitters and enzymes during ischemia in gerbil cerebral cortex. 3 75

Plasma membranes from normal, full-term human placental trophoblast have been isolated by a new procedure. The method depends upon isopycnic zonal centrifugation using linear sucrose/Ficoll density gradients. Enrichment of plasma membrane marker enzymes with respect to trophoblast homogenate is found in two distinct peaks (designated B and D) of the fractionated effluent recovered from the rotor. Fraction B is enriched with membrane-bound alkaline phosphatase and 5'-nucleotidase, but not with (Na+, K+)-ATPase of F(-)-stimulated adenylate cyclase. It is suggested that this material is derived from the maternal-facing microvillous plasma membrane. Fraction D, enriched with (Na+, K+)-ATPase, F(-)-stimulated adenylate cyclase and, to a smaller extent, with 5'-nucleotidase and alkaline phosphatase is, by exclusion, proposed to be derived from the fetal-facing basal plasma membrane. Both plasma membrane fractions are shown to be free of appreciable contamination, using specific markers for endoplasmic reticulum, mitochondria, nuclei and lysosomes. The separation of the two membrane fractions is shown to depend both upon these membranes forming closed vesicles during homogenization and upon the buoyant densities of such vesicles differing in such a way that microvillous plasma membranes band at a lower density than basal plasma membranes. No separation of the membranes is achieved in gradients in which the vesicles are collapsed.
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PMID:Separation of the microvillous (maternal) from the basal (fetal) plasma membrane of human term placenta: methods and physiological significance of marker enzyme distribution. 9 48

It has been shown that the activity of Ca(2+)-ATPase increases during development. Epinephrine in vivo increases the activity of Ca(2+)-ATPase in chick skeletal muscles. The effect of hormone is lacking at embryonic stages of development and appears only before hatching. In the presence of exogenous protein kinase, cAMP also increases the activity of the enzyme, this effect being observed also in embryonic muscles. Lack of effect of epinephrine on Ca(2+)-ATPase in embryonic muscles is associated with non-reactivity of their adenylate cyclase to catecholamines. Ca(2+)-ATPase itself already at embryonic period is ready to react to cAMP. It is concluded that Ca(2+)-ATPase of sarcoplasmic reticulum is one of the sites of action of catecholamines on calcium metabolism in muscle cell and that this action is realized via the system adenylate cyclase-cAMP-protein kinase.
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PMID:[The effect of catecholamines on the Ca2(+)-adenosinetriphosphatase of the sarcoplasmic reticulum in the skeletal muscles in chicken ontogeny]. 9 34

A plasma membrane preparation purified from guinea pig ventricles without the use of high concentrations of detergents or structure-disrupting salts was used to compare the mechanisms of controlling sodium, potassium-activated adenosinetriphosphatase (Na, K-ATPase) and adenylate cyclase activities. The basal ATPase activity of 4-6 mu moles P1/hour mg-1 protein, measured in 120 mM NaC1 or KC1, was approximately doubled in 100 mM NaC1 plus 20 mM KC1. This increment, the Na, K-ATPase, was abolished by 10-5M ouabain, the K1 for ouabain being approximately 3 X 10-7M. 1-Epinephrine had no effect on Na, K-ATPase, but NaF was inhibitory. Adenylate cyclase, which had a basal activity of approximately 50% by NaC1 or KC1 alone at concentrations up to 0.2M. There was no additional stimulation of adenylate cyclase activity when na+ K+ included together. Both 1-epinephrine and NaF cause significant stimulation of adenylate cyclase, but neither basal nor activated cyclic AMP PRODUCTION WAS INFLUENCED BY OUABAIN. Half-maximal stimulation was seen at approximately 5 X 10-6M 1-epinephrine. Both the catecholamine and NaF increased the V-max ofcardiac plasma membrane adenylate cyclase without significantly influencing Km. Increasing Ca2+ in the range between 10-7 and 10-3M inhibited basal, 1-epinephrine-stimulated, and NaF-stimulated activities. Basal rates of cyclic AMP production were more sensitive to Ca2+ than was 1-epinephrine stimulation was increased from approximately 60% in 0.5 mM EGTA to approximately 150% in 10-7M Ca2+ and 400% in 10-5M Ca2+. The inhibitory effect of Ca2+ on adenylate cyclase activity may represent a negative feed back mechanism by which elevation of intracellular Ca2+ concentration lowers cellular levels of cyclic AMP and thus reduces Ca2+ influx into the myocardium.
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PMID:Control of cardiac sarcolemmal adenylate cyclase and sodium, potassium-activated adenosinetriphosphatase activities. 12 80

Adenosine triphosphatase (ATPase) activities were compared in platelets of asthmatic and nonasthmatic children. Significantly elevated Mg2+- and Ca2+-dependent ATPase activities were found in particulate and soluble fractions of platelets from nonsteroid-treated asthmatic children compared to steroid-treated asthmatic and nonasthmatic children. The most pronounced increase (greater than twofold) occurred in the Ca2+-ATPase of the soluble fraction which contains platelet contractile protein. Intact cell surface of ecto ATPase activity was not significantly increased in platelets of asthmatic children. The findings are consistent with adrenergic imbalance in asthma involving depressed adenylate cyclase activity (beta-adrenergic) and increased ATPase activity (alpha-adrenergic) and may relate to abnormal platelet aggregation patterns.
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PMID:Increased adenosine triphosphatase activity in platelets of asthmatic children. 12 27

The hormonal responsiveness of plasma membrane-bound enzymes (Na-+-K-+)-ATPase and adenylate cyclase has been investigated in normal and regenerating rat liver. (Na-+-K-+)-ATPase basal activity is not affected by surgery and only slightly affected by partial hepatectomy; its response to epinephrine and cyclic AMP is decreased only 15 h after hepatectomy. Adenylate cyclase activity of plasma membranes from untreated animals is stimulated by parathyroid hormone and thyroxine; partial hepatectomy increased basal activity as well as the stimulation exerted by the aforementioned hormones, when glucagon and epinephrine sensitivity is essentially unaltered.
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PMID:Hormone responsiveness of plasma membrane-bound enzymes in normal and regenerating rat liver. 12 2

An in vitro inhibitor of Na-K-ATPase was discovered in a commonly used preparation of ATP made by the Sigma Chemical Company, St. Louis, Mo. (Sigma grade ATP). As measured by a reliable and widely used assay system in which phosphate liberation in measured colorimetrically, Na-K-ATPase activity in the rat kidney, small intestine and colon was about 50% lower then Sigma grade ATP was used as substrate as compared to another Sigma Chemical Company product II ATP. Mg-ATPase and adenylate cyclase assays were unaffected by substituting Sigma grade for grade II ATP. The inhibitor of Na-K-ATPase could not be identified. Sigma grade ATP probably should not be used when measuring the activity of Na-K-ATPase in the rat kidney, small intestine, or colon.
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PMID:An in vitro inhibitor of Na-K-ATPase present in an adenosinetriphosphate preparation. 12 55


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