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:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Methods have been developed for the isolation on a semi-micro scale of a plasma membrane-enriched fraction from rat islets of Langerhans. An important feature of these experiments is the use of 125I-labeled wheat germ agglutinin as a specific probe for plasma membrane-containing fractions. The partly purified plasma membrane fraction had a density in sucrose of about 1.10 and was enriched in the activities of 5'-nucleotidase, alkaline phosphatase, sodium-potassium, and magnesium-dependent ATPase and adenylate cyclase. It contained only very low levels of acid phosphatase, cytochrome c oxidase, insulin, and RNA. Further purification was hampered by the relatively small amounts of fresh plasma membrane material that could be obtained from 16-24 rats in each experiment. When islets were prelabeled with radioactive fucose, the plasma membrane-enriched fraction contained radioactivity at a four- to fivefold higher specific acivity than the whole islet homogenate. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis of plasma membrane-enriched fractions pooled from several experiments revealed a distinctive pattern of protein bands as compared with other less pure fractions. With respect to rapidity, apparent specificity, and easy reversibility of the labeling of the plasma membrane fraction, 125I-wheat germ agglutinin provides a highly useful tool for the detection of microgram quantities of plasma membrane components which should be applicable to many other systems as well.
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PMID:Preparation and characterization of plasma membrane-enriched fractions from rat pancreatic islets. 79 56

The structure and histochemistry of the palmar and plantar skin were studied in four adult male marmosets (two Callithrix jacchus and two Callithrix penicillata). In this skin there exist well-developed epidermal ridges, to which are attached one or two ducts of sweat glands. A thick stratum corneum can be seen in the epidermis, while a distinct stratum lucidum cannot be isolated from the other layers. The stratum granulosum is constituted by one or three layers of cells containing keratohyalin granules. Melanin granulations are mainly concentrated in the basal cells of the epidermal ridges. Dendritic melanocytes and amelanotic melanocytes containing alkaline phosphatase are found among the epidermal cells. Glycogen, UDPG-GT and phosphorylases are mainly present in the middle and lower Malpighian cells of the epidermal ridges. Alkaline phosphatase, ATPase, alanyl amino-peptidase and leucine aminopeptidase were absent in the epidermal cells. SDH, cytochrome oxidase, MAO and a certain number of NAD-dependent dehydrogenases (LDH, ADH, MDH, alpha-GPDH, beta-OHBDH and GDH) showed a stronger reactivity in the basal cells and Malpighian layer. The NADP-dependent enzymes (G-6-PDH, 6-PGDH, cis-aconistase and ICDH) were more reactive in the upper Malpighian layer and stratum granulosum. The stratum corneum showed some acid phosphatase and nonspecific esterase reactivity. The collagenous fibers intertwined with a small number of very thin elastic ones and a larger amount of reticular fibers run almost parallel to the epidermal ridges in the papillary body. In the reticular dermis some fibers are disposed transversely to the epidermal ridges. Meissner corpuscles reactive to butyrylcholinesterase, acetylcholinesterase, nonspecific esterase and G-6-PA are disposed at regular intervals and frequently at each side of the epidermal ridges. Pacinian corpuscles were found only in the hypodermis. The eccrine sweat glands contain glycogen, UDPG-GT and phosphorylase in their secretory, ductal and myoepithelial cells. The secretory part shows a uniform reactivity for every dehydrogenase because it contains only one type of cells (clear cells). The intraepidermal segment of the ducts shows a stronger reactivity to nonspecific esterase and NADP-dependent dehydrogenases than the epithelial cells around it.
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PMID:The skin of the palms and soles of the marmosets (Callithrix jacchus and Callithrix penicillata). 82 86

Two subfractions of bovine thyroid plasma membranes, light membranes (L-membranes) and heavy membranes (H-membranes), were obtained by a discontinuous sucrose gradient centrifugation of plasma membranes. Electron microscopy of the plasma membrane and its subfractions showed that the H-membranes were very similar to the plasma membrane fraction, both contained junctional complexes, long membrane sheets, and vesicles. In contrast, the L-membranes consisted mainly of short membrane sheets and vesicles, and only a few junctional complexes. The H-membranes had greater adenylate cyclase activity which responded to thyroid-stimulating hormone (TSH) while this hormone had very little effect on the enzyme activity in the L-membranes. Despite the marked difference in TSH stimulation of adenylate cyclase activity in the H- and L-membrane fractions, specific binding of 125I-TSH was similar in both fractions. The L-membranes had higher specific activities of 5'-nucleotidase and Mg2+ATPase while (Na+ + K+)-ATPase and alkaline phosphatase activities were similar in the two subfractions. Protein kinase activity of H-membranes was not significantly stimulated by exogenous cyclic adenosine 3':5'-monophosphate (cAMP). Plasma membranes and H-membranes contained a substrate capable of being phosphorylated. Such phosphorylation was slightly increased by addition of soluble protein kinase. The phosphorylation of exogenous histone by protein kinase of plasma membranes and H-membranes was augmented by cAMP. In contrast, L-membranes had very little protein kinase activity even when exogenous histone was added. They were not a very good substrate for cytosolic protein kinase.
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PMID:Preparation and characterization of subfractions of bovine thyroid plasma membranes. 85 12

Human erythrocyte ghosts were solubilized in a low ionic strength medium containing 1% Triton X-100 and subjected to electrophoresis in polyacrylamide gels containing Triton X-100. Five major bands were stained with Coomassie Blue, all except one band being heterogenous when re-electrophoresed in gels containing sodium dodecyl sulphate. It was possible to detect acetylcholinesterase, non-specific esterase, ATPase, alkaline phosphatase, 5'-nucleotidase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and aldolase activities on the Triton-containing polyacrylamide gels. Two of the enzymes, ATPase and 5'-nucleotidase, showed substantial inhibition by Triton X-100 in quantitative studies. This appears to be a useful method for studying membrane enzymes in normal and pathological red cells.
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PMID:Polyacrylamide gel electrophoresis of human erythrocyte membrane enzymes solubilized with triton X-100. 89 Sep 65

The subcellular distributions of alkaline phosphates I (the major activity of prepubertal mouse ovaries) and alkaline phosphatase Ib (a kinetically distinct isoenzyme induced in large amounts by injection of human chorionic gonadotropin or luteinizing hormone) were studied by differential rate centrifugation and discontinuous density gradient centrifugation of ovarian homogenates from control and gonadotropin-treated mice. The distributions of the two alkaline phosphatases were alike and were similar to those of nucleotidase, Mg2+ -dependent ATPase and Co2+ -stimulated naphthylamidase activities, suggesting that they were associated with plasma-membrane vesicles.
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PMID:Subcellular distribution of a gonadotropin-induced form of mouse ovarian alkaline phosphatase. 100 1

Fluoride concentrations in plasma 3 hr after a single oral dose of NaF (5 mg/100 g body weight) were increased 26 times above the control, but the concentrations in erythrocytes and red cell membranes were increased only 1.8 and 1.5 times over the respective control levels. Ionic concentrations of magnesium and calcium in erythrocytes and their membranes were significantly changed by fluoride administration, but the ionic concentrations in plasma were not statistically changed in comparison with controls. Acid phosphatase activities in plasma and erythrocytes were significantly decreased by fluoride administration, but alkaline phosphatase activity in the plasma was not changed. Mg2+-activated ATPase activity was significantly elevated in the erythrocyte membrane by fluoride administration; (Na+ + K+)-activated ATPase activity was significantly decreased in the membrane.
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PMID:Changes of ion mobilizations and their related enzyme activities in the blood of fluoride-intoxicated rats. 101 Dec 89

A bile canalicular membrane fraction was isolated from 24-hour regenerating rat livers, and its properties were compared to those of homologous fractions prepared from the livers of sham-operated and unoperated controls. These canalicular membrane fractions were found to be closely related in terms of their morphology, their purity, their yield, and their qualitative protein banding profiles on sodium dodecyl sulfate-polyacrylamide gels. However, when a rigorous examination of plasma membrane enzyme marker activities was made, the regenerating liver membranes were shown to possess an increased specific activity of alkaline phosphatase and lower levels of Mg2+ ATPase and 5'-nucleotidase in comparison with control specific activity values.
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PMID:Isolation and partial characterization of a bile canalicular plasma membrane fraction from normal and regenerating rat liver. 115 69

Growth plate cartilage from rachitic rats was studied to assess the role of extra-cellular matrix vesicles in the reinstitution of calcification during healing. The concentration and distribution of matrix vesicles was found to be normal in rachitic growth plate, and although the rachitic cartilage matrix was largely uncalcified, an occasional vesicle did contain internal mineral. Matrix vesicles served as initial loci for mineralization when healing was brought about either by in vivo injection of phosphate or in vitro incubation of growth plates in a metastable calcifying solution. During in vitro calcification a distinct line of mineralization developed in the upper growth plate which was shown by electron microscopy to reflect mineralization by the vesicles. The appearance of this vesicle-associated calcification line was inhibited by preheating or repeated freezing and thawing, and by 30 minutes preincubation in deoxycholate, ethane-1-hydroxy-1,1-diphosphonate, or beryllium sulfate. Our results suggest that vesicle calcification is dependent on the structural and enzymatic integrity of the vesicle membrane. Enzymes that may well play a role in vesicle calcification are phosphatases (e. g., alkaline phosphatase, pyrophosphatase and ATPase), which are known to be concentrated in vesicle membranes.
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PMID:Calcification of rachitic cartilage to study matrix vesicle function. 124 48

Renal epithelial function, proton flux and sodium stimulated proton flux, was observed in vesicles isolated from the brush border of the proximal tubule of Sockeye Salmon (Oncorhynchus nerka) during migration. Brush border membrane vesicles (BBMV) were isolated from the body kidney of Sockeye Salmon using aggregation/differential centrifugation techniques. Vesicle purity was tested using a series of epithelial and basal lateral markers including alkaline phosphatase, maltase, gamma-glutamyl transferase (GGTP), Mg(2+)-activated ATP-ase, Na(+)+K(+)-activated ATPase, and 5'-nucleotidase and the lysosomal marker acid phosphatase. An enrichment/depletion factor for each marker was determined by comparison of purified BBMV with kidney homogenate. Vesicles exhibit an enrichment factor for alkaline phosphatase, GGTP, maltase, Mg(2+)-activated ATP-ase, Na(+)+K(+)-activated ATPase, and 5'-nucleotidase. A depletion factor was observed for acid phosphatase. Vesicle integrity was tested by measuring the time course of proton flux in the presence of a pH gradient. Amiloride sensitive sodium stimulated proton flux was observed in these vesicles. The presence of sodium caused a saturable increase in the rate of proton flux, indicating the activity of a sodium/proton antiport protein in BBMV.
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PMID:Proton transport and Na+/H+ exchange in vesicles isolated from sockeye salmon (Oncorhynchus nerka) kidneys during migration from salt to fresh water. 132 4

1. Two distinct patterns of Ca(2+)-mediated activation of Ca(2+)-ATPase were identified in calmodulin-depleted membranes. 2. In membranes showing no activation (type A), preincubation with micromolar concentration of cyclic AMP and ATP made possible stimulation of the enzyme while in membranes already exhibiting activation (type B), preincubation with cyclic AMP and ATP abolished the activation. 3. ATPase stimulation in type A membranes was suppressible by leupeptin. 4. Triton extractable inhibitor isolated from type A membranes was as active as that derived from type B membranes only after preincubating the membranes with cyclic AMP and ATP. 5. The inhibitor could be inactivated by alkaline phosphatase.
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PMID:Variations in Ca(2+)-mediated activation of Ca(2+)-ATPase and its associated inhibitor in erythrocyte membrane. 132 91


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