Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Ca2+-binding glycoprotein isolated from preosseous cartilage shows also alkaline phosphatase activity. The purification procedure indicates that the enzyme is inhibited in crude extract and conceivably in the intact tissue; the activity may be controlled by the proteoglycans present in the matrix. Other substrates are hydrolyzed by the purified enzyme in addition to p-nitrophenylphosphate; the highest specific activity was measured with ATP and pyrophosphate (PPi) at pH 7.5 and 9.0 Mg2+ induces an activation of ATP and PPi hydrolysis; Ca2+ activates hydrolysis of ATP but inhibits that of PPi. The glycoprotein shows also transphosphorylase activity, L-serine being the best phosphate acceptor. The release or transfer of Pi catalyzed by the glycoprotein can be an important step in calcium phosphate precipitation.
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PMID:Enzymatic properties of the Ca2+-binding glycoprotein isolated from preosseous cartilage. 11 41

During the activation of the inactive dinitrogenase reductase from Rhodospirillum rubrum, an adenine-like molecules is lost and phosphate is found on both active and inactive forms of the protein. ATP and divalent metals are required for activation of the reduced protein, but ATP is not required for activation of phenazine methosulfate-oxidized dinitrogenase reductase. Snake venom diesterase and spleen diesterase have no effect on the inactive protein; alkaline phosphatase removes phosphate from the activated protein but not from the inactive protein. ATP binds to both active and inactive forms of the protein.
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PMID:Removal of an adenine-like molecule during activation of dinitrogenase reductase from Rhodospirillum rubrum. 11 62

Bone ECF is separated from the general ECF by a functional membrane which has been shown to limit the mineralization of embryonic tibiae and to selectively pump Ca out of the bone ECF. Energy to run this pump may be derived from ATP hydrolyzed by Ca-2+-stimulated ATPase, an enzyme activity which bone alkaline phosphatase may possess. The data suggest that PTH rapidly and selectively increases Ca pumping possibly by increasing ATPase activity in the bone cell cytosol through increased Ca influx and by increasing the intracellular ATPase level through inhibited secretion or excretion of the enzyme.
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PMID:Cellular control of calcium movements in bone. Interrelationships of the bone membrane, parathyroid hormone and alkaline phosphatase. 12 41

The activity of adenosine triphosphatase and alkaline phosphatase was investigated at the fine structural level in the cyst stages of Sarcocystis tenella parasitic in the esophagus of sheep. Alkaline phosphatase reaction was observed along the outer membrane of the parasite's pellicle. The enzymatic activity was much higher on the surface of metrocytes than that of zoites, which proved to be infectious. No reaction was noted in the interior of the parasites. However, a significant amount of alkaline phosphatase activity occurred along the inner surface of the 25 nm thick primary layer of the cyst wall. No evidence of the reaction of this enzyme was seen in the secondary cyst wall, which consisted of degenerated host cells. ATP-ase activity was found in a considerable degree along the primary cyst wall (=directly limiting the cyst's interior), whereas the ground-substance of the cyst, surrounding the parasites, is free of deposits. In the parasites ATP-ase was localized in the endoplasmic reticulum, in the perinuclear space, and between the two inner membranes of the three-layered pellicle. Only rarely a slight reaction was seen in the mitochondria of the metrocytes, which are the reproductive cells. The other organelles typical for S. tenella were free of ATP-ase. The results indicate that the enzymes studied participate in the growing process of the cysts, in which finally the infectious zoites remain in a more or less inactive state. The localizations of the enzymes corresponded with the results known from metazoa.
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PMID:[Ultrastructural localization of alkaline phosphatase and ATP-ase in cyst stages of Sarcocystis tenella (Sporozoa, Coccidia) parasitic in the esophagus of sheep (author's transl)]. 12

In the present investigations, the localization of several enzymes (Acid Phosphatase, Peroxidase, succinic dehydrogenase, Phosphorylase, alkaline phosphatase, ATP-ase) and other substances in the guard and subsidiary cells as well as trichomes of the leaves of Phaseolus mungo, was carried out. Attempts were also made to follow the sequence of developmental stages starting with meristemoids and culminating in differentiated structures. The basic information thus obtained is used in interpreting the developmental physiology of stomatal differentiation as well as their cellular organisation. Histochemical observations made in the present studies are compared with the electron microscopical observations of Whatley (1972). It is proposed that mitochondria played a basic role in the functioning of the guard cells. The present studies also demonstrated activity of acid phosphatase in the guard cells and was localized in spherosomes. The latter varied in the activity for acid phosphatase and was dependent on the turgid level of the cell. Interestingly, enough localization of phosphatase could only be observed in spherosomes when the osmotic pressure in the cell was relatively low, once the osmotic pressure increased, the activity disappeared.
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PMID:Histochemical studies in stomatal apparatus of Phaseolus mungo Linn. I. Localization of enzymes and structural material. 12

The histochemical studies were carried out in the open and closed stomata of Phaseolus mungo leaves. Several enzymes like, Acid phospatase peroxidase, succinic dehydrogenase, phosphorylase, alkaline phosphatase, ATP-ase etc. were localized in the guard and subsidiary cells of epidermal peel. On the basis of cytochemical localization, enzyme activity was precisely interpreted. In the light of fluctuations in the localization, activities of different enzymes, an attempt is made to provide the functional interpretation of stomatal mechanism. We have attempted to correlat our observations in relation to diurnal metabolisms. Our studies suggest that starch-sugar inter-changes played a vital role in the stomatal regulation. We are also inclined to believe that besides guard cells, subsidiary cells also influenced the turgid conditions. A model based on available facts in collaboration with our own studies is presented which tends to explain the stomatal regulation.
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PMID:Histochemical studies in stomatal apparatus of Phaseolus mungo linn. IV. Mechanism of stomatal action. 12 1

The structure and the activity of acid phosphatase, beta-glucuronidase, alkaline phosphatase and ATP-ase in the liver and small intestine of rats receiving for 20 days a one-time, fixed at a certain time (2 o'clock) feeding was studied morphologically in dynamics in 2, 6, 24 and 48 hours after the last feeding. Furthermore, parallel with this the activity of acid phosphatase, beta-glucuronidase, alpha-glucosidase and beta-acetylglucosaminidase was determined in homogenates by biochemical methods. Alongside the total activity free activity of beta-acetylglucosaminidase and the activity of this enzyme in the blood plasma was defined. It is shown that during fasting, especially by the 48th hour, there takes place a significant activation of lysosomal enzymes both in the liver and in the small intestine (in the cells of the cylindrical epithelium). A significantly increased permeability of lysosomal membranes (mounting free activity of beta-acetylglucosaminidase) in the liver and of plasmic hepatocytes membranes (higher activity of the enzyme in the blood plasma) was also ascertained. The activation of the lysosomal enzymes is considered to be an adaptive reaction of the organism in fasting.
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PMID:[Histological, histoenzymatic and biochemical study of the liver and small intestine of rats during short periods of starvation]. 12 2

The ATPase of matrix vesicles is not stimulated by calcium ions, nor do the vesicles have any capacity to metabolize glucose. ADPase of high activity is also present; thus vesicles cannot be a component of the conventional ATP cycle, in which energy is stored by phosphorylating ADP and released by hydrolyzing the resultant ATP. These results do not support speculations that matrix vesicles might function by concentrating calcium via an energy-dependent ion transport system such as those found in the plasma membrane and the sarcoplasmic reticulum. Matrix vesicles' alkaline phosphatase can be solubilized by treatment with certain detergents: sodium dodecyl sulfate (12 mM and 16 mM), cetylpyridinium chloride (14mM), and deoxycholic acid (DOC, 14 MM). The first two detergents denature the enzyme during storage whereas DOC does not. DOC will also solubilize ATPase and inorganic pyrophosphatase. Yields of the three enzymes are 85-95%. Dialysis of a DOC digest of vesicles removes DOC and 43% of protein, and also causes much of the alkaline phosphatase to become particulate once again.
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PMID:Matrix vesicles of bovine fetal cartilage: metabolic potential and solubilization with detergents. 12 41

Scolices and brood capsules of healthy hydatid cysts from lungs of human patients were studied with histochemical and histoenzymatic methods. The subtegumental and flame cells were sepcially rich in glycogen, RNA and some dehydrogenases such as SDH, MDH, NADH-reductase and G-6-PDH. The rostellar zone or invaginated pole, an area of marked contractile movements, showed intense activity in ATP'ase and simple esterase. The so-called excretory pole shows strong activity in simple esterases, lipase, beta-HBH, alpha-GDH and NADPH-reductase. Lipids are also abundant in this zone implying the important role of this metabolic path in the development of the parasite. Intense activity in alkaline phosphatase was observed in cells associated to the calcereous corpuscles. The largest corpuscles were devoid of enzymatic activity. The enzyme could play some role in the calcification of the corpuscles. Wide enzymatic variations are described according to morphology being orthoscolices the most rich in enzyme activity. Accumulations of small cells surrounded by specialized cells on the germinal membrane are interpreted as the origin or "embryo" of brood capsules. Some enzymes detected in the wall of mature brood capsules depicted alternating types of cells. Some of them are positive for ATP'ase that may be related to active transport of substances across the brood capsule wall. The intenst ATP'ase activity at the stalks of scolices may be similarly interpreted. However, a miosine-like activity is a more feasible explanation since this area showed striking contractile movements in vivo.
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PMID:Histochemistry and histoenzymology of the hydatid cyst (Echinococcus granulosus Batsch, 1786). II. Scolices and brood capsules. 13 Jul 50

Preparation of surface membranes from mouse L-cells using a technique previously described in the literature [Perdue & Sneider, 1970] allowed characterization of a Ca-activated ATPase apparently separate from the mitochondrial ATPase also dependent on calcium. This enzyme is associated with the Na-K-ATPase, a marker for surface membranes, and not wilth alkaline phosphatase, a mitochondrial enzyme. In temperature sensitivity, pH dependence and inhibition by ethacrynic acid, the partially purified enzyme has properties similar to those previously described for active calcium efflux from these cells. For maximal activity of the enzyme system magnesium and sodium are required, although the calcium transport from whole cells was apparently independent of both. Adenosine triphosphate only was metabolized by the enzyme system, whereas CTP could be utilized for calcium transport from 'ghost' cells, probably as a result of intracellular conversion to ATP. It is suggested that the active calcium transport from cultured L-cells is closely linked to the calcium dependent ATPase, and that the method of calcium extrusion is similar to that described for red blood cells.
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PMID:Properties of the calcium-activated adenosine tri-phosphatase from L-cell membranes. 13 77


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