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)

An enzyme histochemical and cytochemical study of normal dermal microvasculature showed that respiratory enzymes, lipase and non-specific esterase occurred in all vascular segments. Lysosomal enzymes were also widely distributed and acid phosphatase activity was localized in lysosomes, Golgi apparatus and small portions of endoplasmic reticulum of both endothelial cells and pericytes. Alkaline phosphatase activity, however, was confined to the arterial side and tip of the capillary loop where it occurred in vesicles along the luminal surface of the endothelium and in junctions between endothelial cells. The localization of nucleoside phosphatase activity within the endothelium varied according to substrate; with adenosine triphosphate as substrate, the reaction product occurred in vesicles distributed throughout the endothelial cells; with adenosine diphosphate it was limited to vesicles along the luminal surface; and with adenosine monophosphate, activity was mostly localized to the lateral surfaces of endothelial cells. These findings suggest functional variation between different vascular segments and between various components of the endothelium. Attempts to demonstrate a specific Na+K+ adenosine triphosphatase (transport ATPase) within the endothelium were not successful.
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PMID:Human dermal microvasculature: II. Enzyme histochemical and cytochemical study. 723 11

Twenty eight enzymatic activities and four macromolecular substances have been histochemically compared in rat and rabbit aortas, embedded in a common block. The study was carried out at different stages of development: 3 days, 3 months, 7-9 months and 17-19 months. In addition, lipase and cholinesterase were biochemically assayed in adult rat and rabbit aortas. The rat aortas (atheroresistant) had a better supply of aerobic oxidoreductases [linked to the pentose pathway (G6PD, 6PGD) as well as to the Krebs cycle (SD, ICD)], lipolytic enzymes (acid esterases, cholinesterase, lipase), lysosomal enzymes (acid PH/ase, Aryl-sulf/ase - Betaglu/ase), ADPase - ATPase - AlK Ph/ase Alpha GPD and acid lipids. Rabbit aortas (atherosensitive) were richer in metachromatic GAG, UDPGD (GAG Anabolism), glycogen, and related enzymes (phosphorylase, glycogen synthetase) as well as 5'-nucleotidase, Beta HBD, Lactate D and Aldolase. These differences support the hypothesis that arterial atherosensitivity is related to the activity and efficiency of smooth muscle cell energetic and catabolic processes, which govern the behaviour of lipids, proteins and carbohydrates as they penetrate the arterial wall. The factors that determine the proliferative and sclerogenic responses of arterial tissues to aggressions and, in particular, the response to lipids, remain, however, to be determined.
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PMID:A comparative study of the arterial tissue metabolism in atherosensitive and atheroresistant species. I. Comparison between rabbit and rat aortas. 734 89

African swine fever virus polypeptides with molecular weight of 120, 78, 69, 59, 56, 45, 39, 28, 26, 24, 16, and 14 kD are the major proteins in the purified virions, as shown by electrophoresis and immunoblotting. A mixture of proteases and pancreatic lipase hydrolyzed the polypeptides of 120 and 78 kD in viral preparations at low concentrations of enzymes, polypeptides of 69, 56, 45, 39, 28, and 14 kD disappeared after treatment with this mixture at medium concentrations, and 26 kD polypeptide was eliminated at a high concentration of the enzymes. The 21 kD polypeptide which did not react with the specific antiviral serum in immunoblotting was not hydrolyzed by proteases contaminating lipase. Treatment with triton X-100 and ether boosted the activity of DNA-dependent RNA-polymerase, whereas treatment with ether followed by resedimentation markedly decreased polymerase activity in the resultant sediment. Treatment with diethyl ether did not influence the activity of virus-associated ATPase, which was partially resistant to denaturating organic solvents acetone and chloroform-methanol mixture. Our findings and published data permitted us to propose a schematic arrangement of viral polypeptides and enzymes in the virion structure.
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PMID:[Localizing the major peptides of African swine fever virus and virus-associated enzymes in the virion structure]. 747 38

Chronic renal failure (CRF) is associated with increased calcium content of, and impaired lipase release from lipid cells. This has been attributed to a rise in the cytosolic calcium ([Ca2+]i) of these cells. However, data on [Ca2+]i of lipid cells in CRF and on the mechanisms responsible for such an abnormality are lacking. To study this issue we examined the [Ca2+]i and ATP content of lipid cells and Vmax of Na(+)-K(+)-ATPase and Ca2+ ATPase of membrane preparation and Na(+)-Ca2+ exchange of membrane vesicles of adipocytes from normal rats, 6 week CRF, CRF normocalcemic parathyroidectomized (CRF-PTX) and CRF, and normal rats treated with verpamil (CRF-V, normal-V). [Ca2+]i in adipocytes of CRF rats was higher (199 +/- 8.5 nM) and ATP lower (2.9 +/- 0.31 nmol/10(6) cells) than in normal (120 +/- 4.3 nM; 5.7 +/- 0.27 nmol/10(6) cells), CRF-PTX (128 +/- 4.7 nM; 5.8 +/- 0.39 nmol/10(6) cells), normal-V (121 +/- 3.2 nM; 5.3 +/- 0.36 nmol/10(6) cells), CRF-V (123 +/- 7.4 nM; 5.5 +/- 0.30 mmol/10(6) cells). Vmax Ca2+ ATPase and the activity of Na(+)-K(+)-ATPase and of Na(+)-Ca2+ exchanger were reduced in CRF rats as compared to the other four groups of rats. The values in normal, CRF-PTX, CRF-V and normal-V rats were not different.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Elevated cytosolic calcium of adipocytes in chronic renal failure. 764 31

One of the strategies used by Gram-negative bacteria to secrete proteins across the two membranes which delimit the cells is sec-independent and dedicated to proteins lacking an N-terminal signal peptide. Most of these proteins display a C-terminal secretion signal located in the last 60 amino acids (aa). Using one Erwinia chrysanthemi protease, PrtG, secreted by such a pathway it was shown that the smallest C-terminal sequence allowing efficient secretion contains the last 29 aa of PrtG and that low but significant secretion can be promoted by the last 15 aa of PrtG. Moreover, the extreme C-terminal motif, consisting of a negatively charged aa followed by several hydrophobic aa must be exposed and is conserved amongst many proteins following this pathway. This secretion system depends on ABC protein-mediated exporters, which consist of three cell envelope proteins: two inner membrane proteins, an ATPase (the ABC protein), a membrane fusion protein (MFP) and an outer membrane polypeptide. These Gram-negative bacterial protein exporters are dedicated to the secretion of one or several closely related proteins belonging to the toxin, protease and lipase families. The genes encoding the three secretion proteins and the exoproteins are usually all linked, consistent with the specificity of the systems. Er. chrysanthemi metalloproteases B and C and Serratia marcescens hemoprotein HasA are secreted by such homologous pathways and interact with the ABC protein. Interaction between the ABC protein and its substrate has also been evidenced by studies on protease and HasA hybrid transporters obtained by combining components from each system. Association between hemoprotein HasA and the three exporter secretion proteins was demonstrated by affinity chromatography on hemin agarose on which the substrate remained bound with the three secretion proteins. The three components' association was ordered and substrate binding was required for the formation of this multiprotein complex.
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PMID:Protein secretion by Gram-negative bacterial ABC exporters--a review. 922 68

The mechanism of contractile effect of vanadate was investigated in rat aortae. Sodium metavanadate (NaVO3; 10(-5)-3 x 10(-3) M) induced contractile responses in a concentration-dependent manner. Removal of endothelium did not affect the response to NaVO3. The response to NaVO3 was inhibited by nifedipine, a voltage-operated Ca2+ channel (VOC) inhibitor; NCDC, a phospholipase C inhibitor; and H-7, a protein kinase C inhibitor, but not by prazosin, an alpha1-adrenoceptor antagonist; methysergide, a serotonin-receptor antagonist; tripelennamine, a histamine-receptor antagonist; glibenclamide, an adenosine triphosphate (ATP)-dependent K+-channel inhibitor; or iberiotoxin, a large-conductance Ca2+-activated K+-channel inhibitor. In addition, genistein or tyrphostin A48, tyrosine kinase inhibitors, did not affect the contraction induced by NaVO3. Mg2+ removal or antimycin A, a Ca2+-ATPase inhibitor, did not cause any contraction. Ouabain, a Na+, K+-ATPase inhibitor, or K+-free medium caused the contraction of the aortae. The maximal contraction induced by NaVO3 plus ouabain was similar to that induced by NaVO3 alone. In addition, the response to NaVO3 was inhibited by AA861, a 5-lipoxygenase inhibitor, and RHC-80267, a diacylglycerol (DAG) lipase inhibitor. In the presence of AA861, either H-7 or nifedipine further inhibited the residual response to NaVO3. In the presence of NCDC, however, AA861 failed further to affect the residual response to NaVO3. In rat aortae, NaVO3 increased the levels of inositol monophosphate (IP) and prostaglandin F2alpha (PGF2alpha). AA861 and NCDC inhibited the IP increase. In addition, NCDC inhibited the PGF2alpha increase. These results suggest that the response to NaVO3 in rat aortae may be mainly the result of the increased phosphoinositide metabolism.
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PMID:The contractile mechanism of sodium metavanadate in isolated rat aortae. 926 25

The isolated, perfused rat mesenteric bed releases a cytochrome P450-linked metabolite of arachidonic acid (AA) as endothelium-derived hyperpolarizing factor (EDHF) in response to acetylcholine and histamine. This study assessed the relative contribution of two AA-generating pathways, phospholipase A2 (PLA2) and diacylglycerol (DAG) lipase, to EDHF-mediated dilation of the rat mesenteric bed. We tested the hypothesis that PLA2-mediated release of AA is essential for the production of EDHF. Mesenteric beds were perfused with physiological salt solution (PSS) containing indomethacin and nitro-L-arginine methyl ester to block cyclooxygenase and nitric oxide synthase, respectively, and constricted with cirazoline (an alpha1-adrenoceptor agonist). Bolus applications of acetylcholine and histamine caused dose-dependent dilation of the constricted beds. The 85-kDa PLA2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3), at 3 microM, profoundly blunted decreases in perfusion pressure initiated by 1 nmol acetylcholine (94.3+/-1.7%) and by 100 nmol histamine (88.5+/-3.3%) to 9.6+/-7.5 and 8.6+/-6.0%, respectively. AACOCF3 also blocked cirazoline-stimulated release of 6-keto-PG1alpha, but did not alter the vasodilation initiated by sodium nitroprusside (a nitric oxide donor), cromakalim (a K+ channel activator), or by Na+/K+-ATPase activation, as measured by KCl vasodilation in preconstricted beds perfused with K+-free PSS. The 14-kDa PLA2 inhibitor, oleyloxyethyl phosphorylcholine, also blocked EDHF vasodilation and also significantly inhibited K+ channel activity. Neither the Ca2+-independent PLA2 inhibitor, HELSS [E-6-(bromomethylene)-tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one], nor DAG lipase inhibitor, RHC-80267 [1,6-bis-(cyclohexyloximino-carbonylamino)-hexane] altered EDHF-mediated vasodilation. However, RHC-80267 blocked cirazoline-stimulated release of 6-keto-PGF1alpha. We conclude that Ca2+-dependent PLA2, rather than DAG lipase, generates the AA for the production of EDHF in the perfused rat mesenteric bed.
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PMID:Calcium-dependent phospholipase A2 mediates the production of endothelium-derived hyperpolarizing factor in perfused rat mesenteric prearteriolar bed. 948 93

To determine how angiotensin II inhibits the Na(+) pump (Na(+), K(+)-ATPase) in rat zona glomerulosa, we selectively blocked signaling proteins that could be activated by the angiotensin AT(1) receptor and known to affect Na(+) pump activity. Inhibitors of protein kinase C [calphostin C (1 microM); staurosporine (1 microM)], phospholipase A(2) [arachidonyl triflouromethyl ketone (25 microM); quinacrine (75 microM)], diacylgycerol lipase [RHC-80267 (5 microM)], and tyrosine phosphorylation [tyrphostin 47 (100 microM)] had no effect on angiotensin II inhibition of the Na(+) pump. On the other hand, inhibitors of tyrosine phosphatases [phenylarsine oxide (5 microM) and 4-bromotetramisole oxalate (100 microM)] blocked angiotensin II inhibition, where as inhibitors of serine/threonine phosphatases [okadaic acid (1 microM) and microcystin (1.5 microM)] did not. Thus, angiotensin II inhibition of the Na(+) pump may in part be mediated by a tyrosine phosphatase.
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PMID:Inhibitors of tyrosine phosphatases block angiotensin II inhibition of Na(+) pump. 1101 Oct 32

In the immediate posthatch period, chicks must transfer from metabolic dependence on yolk to utilization of exogenous feed. This study describes changes in intestinal luminal pancreatic enzyme activity and mucosal uptake posthatch as influenced by feed and Na intake. Chicks with access to feed increased in BW and small intestinal weight in the 48-h posthatch, whereas chicks without access to feed decreased in BW; however, small intestinal weight increased during this period. Chicks ingesting feed showed increases in total intestinal trypsin, amylase and lipase activities that were correlated with intestinal weights and BW. Chicks without access to feed showed little change in trypsin and amylase activities, and these increased only after feed consumption. Feeding a low-Na diet did not significantly change the regression coefficient between pancreatic enzyme activity and BW. Mucosal uptake was estimated by measuring Na+,K+-adenosine triphosphatase (ATPase) activity in small intestinal segments. In fed birds this activity increased in relationship to growth, whereas in nonfed birds uptake increased only after access to feed. Low-Na diets allowed only minimal mucosal uptake in all intestinal segments. This study indicates that secretion of trypsin and amylase into the intestine was triggered by feed intake. In addition, Na plays a critical role in intestinal uptake in the immediate posthatch period.
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PMID:Hydrolysis and absorption in the small intestines of posthatch chicks. 1102 76

Previously, we had demonstrated that a Legionella pneumophila prepilin peptidase (pilD) mutant does not produce type IV pili and shows reduced secretion of enzymatic activities. Moreover, it displays a distinct colony morphology and a dramatic reduction in intracellular growth within amoebae and macrophages, two phenotypes that are not exhibited by a pilin (pilE(L)) mutant. To determine whether these pilD-dependent defects were linked to type II secretion, we have constructed two new mutants of L. pneumophila strain 130b. Mutations were introduced into either lspDE, which encodes the type II outer membrane secretin and ATPase, or lspFGHIJK, which encodes the pseudopilins. Unlike the wild-type and pilE(L) strains, both lspDE and lspG mutants showed reduced secretion of six pilD-dependent enzymatic activities; i.e., protease, acid phosphatase, p-nitrophenol phosphorylcholine hydrolase, lipase, phospholipase A, and lysophospholipase A. However, they exhibited a colony morphology different from that of the pilD mutant, suggesting that their surfaces are distinct. The pilD, lspDE, and lspG mutants were similarly and greatly impaired for growth within Hartmannella vermiformis, indicating that the intracellular defect of the peptidase mutant in amoebae is explained by the loss of type II secretion. When assessed for infection of U937 macrophages, both lsp mutants exhibited a 10-fold reduction in intracellular multiplication and a diminished cytopathic effect. Interestingly, the pilD mutant was clearly 100-fold more defective than the type II secretion mutants in U937 cells. These results suggest the existence of a novel pilD-dependent mechanism for promoting L. pneumophila intracellular infection of human cells.
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PMID:Type II protein secretion is a subset of the PilD-dependent processes that facilitate intracellular infection by Legionella pneumophila. 1125 62


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