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)

On the basis of electron microscopic evidence, a preparation of microvilli obtained from the surfaces of placental villi was previously considered by us to represent syncytiotrophoplast plasma membrane. The present investigation was undertaken to obtain independent biochemical evidence on the nature of the preparation. Protein, lipid, carbohydrate, sialic acid, phospholipid and cholesterol concentration were determined and found to be consistent with analyses of membranes obtained from other sources. Enzyme membrane markers (5'-nucleotidase, (Na+ + K+)-ATPase and alkaline phosphatase) were also assayed, and found to be considerably enriched in the microvillous preparation compared to the whole placental homogenate. These findings, together with other evidence, support the contention that the preparation is indeed syncytiotrophoblast plasma membrane.
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PMID:Preparation and characterization of human syncytiotrophoblast plasma membrane. 15 76

The pattern of response of the intestinal enzymes Ca2+-activated adenosine triphosphatase and alkaline phosphatase in the chick to 1,25-dihydroxycholecalciferol is consistent with a role for the former but not the latter enzyme in the vitamin D-dependent absorption of calcium.
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PMID:Differentiation of the changes in alkaline phosphatase from calcium ion-activated adenosine triphosphatase activities associated with increased calcium absorption in chick intestine. 15 34

In this study, enzyme activities of the pancreatic appendages of the ductus hepatoPancreas (the so-called "pancreas") in Sepia officinalis L. have been demonstrated by light and electron micicroscopical methods: Malate dehydrogenase, monoamine oxidase, acid phosphatase, beta-glucuronidase, adenosine triphosphatase and carbonic anhydrase were shown by the former, and monoamine oxidase, catalase, glutamic oxalacetic transaminase, choline esterase (non-specific), alkaline phosphatase, acid phosphatase and carbonic anhydrase by the latter technique. The correlation between enzyme activity and distribution, and the presumed function of the two pancreatic epithelia is discussed.
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PMID:The localization of enzyme activities in the pancreatic appendages of Sepia officinalis L. (Cephalopoda). 15 95

The same isoenzyme of nonspecific alkaline phosphatase (APase), assayed with p-nitrophenylphosphate (p-NPP), was shown be present in different calcifying tissues, bone, calcifying cartilage, odontoblasts and enamel organ. Indications were also found that the enzymatic degradation of inorganic pyrophosphate (PPi) in calcifying tissues is mediated by APase. By using specific APase inhibitors, it was shown that two enzymes capable of degrading ATP exist. These were characterized in dentinogenically active odontoblasts, and it was concluded that one is the classical APase, the other is a Ca2+ and Mg2+ activated ATPase, named Ca2+-ATPase. The two phosphatases were solubilized from odontoblasts and separated. The localization of APase and Ca2+-ATPase in odontoblasts was investigated by subcellular fractionation and EM histochemistry. Routine methods for fixation were found to almost completely inactivate the enzymes. By using a mild fixation technique that preserved 80% of the enzyme activity, the main localization for both APase and Ca2+-ATPase was found to be in the membranes of intercellular vesicles located in the cell body and odontoblasts process. No activity was found in the cell membranes. It is concluded that there are at least two enzymes able to degrade phosphate compounds at alkaline pH in hard tissue forming cells. One is the nonspecific alkaline phosphatase (APase; EC 3. 1. 3. 1), which is active against p-NPP, PPi, glycerophosphates and ATP among other substrates. The other is a more specific Ca2+-ATPase (EC 3. 6. 1. 3). There seems to be an intimate relation between these two enzymes in the tissue. The function of APase in biological calcification is still obscure. In contrast, the finding of an ATP dependent, intravesicularly directed, transmembranous Ca2+-transport in vesicles derived from the microsomal fraction of odontoblasts may explain the role of Ca2+-ATPase.
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PMID:Odontoblast alkaline phosphatases and Ca2+ transport. 15 9

The study deals with the distribution of acid and alkaline phosphatases, ATPase, 5-nucleotidase, nonspecific esterase, specific cholinesterase, and beta-galactosidase in the diencephalon of the frog. The highlights of the present study are the following: i) Acid phosphatase is present in all the neurons, whereas the tracts and commissures are completely negative. ii) Most of the tracts and commissures are positive for 5-nucleotidase. This confirms the author's previous findings that the tracts and commissures of all the areas of frog brain are intensely positive for 5-nucleotidase. iii) beta-galactosidase activity in the nuclei of the diencephalon is either mild or completely absent, whereas the commissures and tracts show positive activity. iv) Habenulothalamic connections are intensely positive for specific cholinesterase and non-specific esterase, moderately positive for beta-galactosidase and completely negative for other enzymes. v) The epiphysis (pineal organ) shows intense reaction for adenosine triphosphatase, acid phosphatase, and 5-nucleotidase and moderate reaction for alkaline phosphatase and non-specific esterase. In contrast to the above enzymes, the specific cholinesterase and beta-galactosidase are completely missing. vi) Lateral forebrain bundles are completely negative for all the enzymes except alkaline phosphatase and beta-galactosidase. The distribution of these enzymes has been correlated with the functional aspects of various nuclei, tracts, and commissures of the diencephalon of the frog.
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PMID:The chemoarchitectonics of the diencephalon of frog (Rana tigrina). 15 81

Differential centrifugation of rat small intestinal homogenates produced a crude brush border (BB) fraction that was enriched 15-fold for the marker enzymes, alkaline phosphatase and sucrase; contamination with mitochondrial enzymes, monoamine oxidase and succinate dehydrogenase, was minimal. ATP hydrolysis by this BB fraction was stimulated by addition of several anions to the incubation medium: HCO3 and Cl were equally effective in this regard, with NO3, NO2, SO4, and acetate being less stimulatory. SCN and CNO inhibited ATPase activity, whereas the divalent anion SO3 was stimulatory at low concentrations (less than 25 mM) but inhibitory at 100 mM. Maximum anion stimulation was observed at a Mg concentration of 0.5 mM, and pH optimum was 8.5. Kinetic analysis showed that HCO3 increased the Vmax without altering the Km for ATP; the Ka for this effect of HCO3 was 35 mM. This enzyme activity was completely inhibited by 20 mM L-phenylalanine, 10 mM L-cysteine, and 3 mM EDTA, compounds that also inhibited intestinal alkaline phosphatase. These results demonstrate the presence of anion-stimulated ATPase activity in rat small intestinal brush border and suggest that this activity may be related to intestinal alkaline phosphatase. The role of this enzyme in intestinal transport is not known, but could relate to the regulation of intestinal absorption and secretion.
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PMID:Anion-stimulated ATPase activity of brush border from rat small intestine. 15 3

The plasma membrane enzymes, alkaline phosphatase, bicarbonate-dependent adenosine triphosphatase, 5'-nucleotidase, and carbonate dehydratase, were measured in ductal and acinar preparations of bovine pancreas. Epithelial cells were scraped from the main duct and a piece of acinar tissue was dissected from the whole pancreas for homogenization. All enzymes studied demonstrated higher levels in the duct per milligram protein than in the acinus: bicarbonate-dependent adenosine triphosphatase was 2.8 times higher; 5'-nucleotidase, 4.1 times higher; carbonate dehydratase, 16.9 times higher, while alkaline phosphatase showed only a slight increase in the duct compared to acini.
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PMID:Enzymic profiles of bovine pancreatic ductal and acinar tissues. 15 38

The alkaline phosphatase and (Ca2+ +Mg2+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) of chick and rat small intestine have been investigated. The same pH optimum was found for membrane-bound and solubilized alkaline phosphatase, whereas those of the corresponding ATPases differed. The solubilised ATPases had inhibition and activation characteristics similar to those of alkaline phosphatase but markedly different from those of the membrane-bound ATPase. These results suggest that membrane-bound alkaline phosphatase and ATPase are not the same enzyme.
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PMID:ATPase and alkaline phosphatase activities of chick and rat small intestinal mucosa. 15 75

The effect of exogenous orthophosphate and mutations in genes, regulating the Pi transport system, on the ATPase activity of E. coli subcellular fractions was studied. It was shown that the orthophosphate starvation resulted in the cessation of the increase in the ATPase activity of membranes and was accompanied by the increase in the analogous activity of a soluble fraction at the expense of the derepression of alkaline phosphatase possessing this activity. The disturbance, resulted from the mutation of protein components participating in the specific binding and transport of orthophosphate, changed the ATPase activity of subcellular fractions: increased the ATPase activity of soluble fraction (independently of the presence of orthophosphate in medium), did not affect significantly the activity of membrane--bound ATPase in the presence of orthophosphate and decreased this activity in the absence of orthophosphate. The data obtained point to the fact that components, binding exogenous orthophosphate and transporting it into a cell, affect the rigidity of the ATPase bound E. coli cytoplasmic membrane. Mutations resulting in the defect in these components relax this bound and lead to the detection of ATPase proper in the periplasm.
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PMID:[Exogenous orthophosphate regulation of ATPase activity of E. coli cells]. 15 76

It is suggested that ABRM, smooth muscle of Mytilus edulis L. and Mytilus galloprovincialis Lmk. (Mollusca Pelecypoda), is composed of one histochemical fibre type. The fibres are characterized by a low myofibrillar ATPase activity. Succinic and nicotinamide adenine dinucleotide oxidoreductase activities are distributed in a reverse pattern than that of the ATPase activity. Glycogen phosphorylase is richly represented in ABRM fibres and this detection is in opposition with the negative detection of alkaline phosphatase activity. These preliminary histochemical observations are similar to those found in some vertebrate smooth muscles. Mitochondrial glycerol-3-phosphate, 6-phosphogluconate, lactate and octopine dehydrogenases are not detected in muscle fibres whereas glio-interstitial tissues show weak but distinct reactivity. These last results especially characterize Mytilus catch fibres and are briefly discussed in relationship with previous physiological, biochemical and morphological observations.
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PMID:Histochemical characteristics of a tonic smooth muscle. 15 82


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