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 toxR gene encodes a transcriptional activator controlling cholera toxin, pilus, and outer-membrane protein expression in V. cholerae. Nucleotide sequence and mutational analysis has identified the toxR gene product as a 32,527 dalton protein. Hydropathicity analysis of the derived amino acid sequence of ToxR predicts a transmembrane structure. The properties of hybrid proteins composed of N-terminal fragments of ToxR fused to the periplasmic enzyme alkaline phosphatase provide additional evidence for the transmembrane topology of the ToxR protein. These fusion proteins also allowed the localization of the transcriptional activation and DNA binding domains of the ToxR protein to its cytoplasmically located N-terminal portion. DNA binding assays and a deletion analysis of the cholera toxin promoter support a model for transcriptional activation that involves ToxR binding to a tandemly repeated 7 bp DNA sequence 56 bp upstream of the transcriptional start point.
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PMID:Cholera toxin transcriptional activator toxR is a transmembrane DNA binding protein. 380 95

A phosphorylated 2-keto-3-deoxyoctonic acid (KDO) was released from the lipopolysaccharides of Vibrio cholerae Ogawa and Inaba after strong acid hydrolysis. The phosphorylated KDO was identified by gas-liquid chromatography and mass spectrometry after reduction and permethylation as KDO-5-phosphate and an isomer of it being phosphorylated at position 7 or 8. After treatment with alkaline phosphatase, KDO was detected by gas-liquid chromatography and mass spectrometry. It was indistinguishable from authentic 2-keto-3-deoxy-D-manno-octonic acid.
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PMID:Occurrence of 2-keto-deoxyoctonic acid 5-phosphate in lipopolysaccharides of Vibrio cholerae Ogawa and Inaba. 396 44

Highly purified plasma membranes of bovine thyroid were obtained by differential pelleting followed by discontinuous gradient centrifugation in a swing-out rotor. Subfractions of plasma membranes were prepared by affinity chromatography on Con A-Sepharose. The final membrane fractions were enriched 25-30-fold over homogenate in 5'-nucleotidase and alkaline phosphatase and displayed a protein to phospholipid ratio of 1.67 and a cholesterol to phospholipid molar ratio of 0.55. The phospholipid composition did not deviate appreciably from that of whole tissue except for the higher sphingomyelin level (22.5 vs. 14.0%). The predominant fatty acids were palmitic (16:0), oleic (18:1), stearic (18:0) and linoleic (18:2) acid. The physical state of the membrane was studied by (i) calculation of the lipid structural order parameter SDPH from steady-state fluorescence anisotropy determinations of the hydrophobic probe 1,6-diphenyl-1,3,5-hexatriene (DPH); (ii) estimation of the lateral diffusion coefficient of pyrene following excimer formation. These parameters were determined in native thyroid plasma membranes and in reconstituted vesicles, obtained by detergent dialysis from octylglucoside solubilized membrane components. The presence of membrane protein or neutral lipids induced more restraint on the movements of the fluorophores. The lipid order parameter, SDPH was mainly determined by the neutral lipids. Subfractions of plasma membrane enriched in luminal membranes have a slightly lower fluidity (higher SDPH and lower Ddiff values) than subfractions enriched in basolateral membranes. This difference appears to be due to both differences in lipid as well as protein composition. Under physiological conditions, no significant alterations in probe dynamics could be observed upon addition of thyrotropin or cholera toxin, even at micromolar concentrations.
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PMID:Fluidity characteristics of bovine thyroid plasma membranes. 397

The effect of cholera toxin (CT)-challenge on histochemically demonstrable activities of adenylatecyclase and alkaline phosphatase was investigated in rat small intestine, using an intestinal loop model. CT-challenge increased the activities of adenylatecyclase and alkaline phosphatases within 15 minutes, and the changes were confined to enterocytes in the upper third parts of the villi. There was no change in the staining of the crypt cells. There was an increased basal activity of both adenylatecyclase and alkaline phosphatases in animals desensitized to cholera toxin by multiple peroral exposures. CT-challenge in the desensitized rats did not further increase the enzyme activity. It is concluded that desensitization to secretagogues induces profound alterations in the cell systems responsible for fluid secretion.
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PMID:Alkaline phosphatases and adenylate cyclase in the normal and desensitized rat small intestine after acute cholera toxin challenge: a histochemical study. 409 83

Brush borders and plasma membranes have been purified from mucosal epithelial cells of rabbit ileum under control conditions and after treatment for 3 hr with cholera toxin in vivo. The activity of several enzymes in these preparations was measured. It was concluded that adenyl cyclase, like NaK-ATPase, seems not to be a normal constituent of brush borders. Both these enzymes are present in plasma membrane preparations derived largely from the basal and lateral margins of the epithelial cells, both may be phospholipid dependent enzymes and both are affected by cholera toxin. Adenyl cyclase activity is increased while NaK-ATPase is decreased. The activities of alkaline phosphatase, leucineaminopeptidase, 5'-nucleotidase, glucose-6-phosphatase, and Mg-ATPase were not found to be affected by the toxin. Cholera toxin, which makes contact with the luminal side of the epithelial cells, in the natural disease and in the experimental model, would appear to exert its pathologic effect on adenyl cyclase at the opposite (basal and lateral) side of the cells.
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PMID:Localization of the action of cholera toxin on adenyl cyclase in mucosal epithelial cells of rabbit intestine. 434 29

The present studies were undertaken to determine the role, if any, of cyclic 3',5'-adenosine monophosphate (cyclic AMP) as a chemical inducer of rat liver alkaline phosphatase. Cholera enterotoxin, given intravenously to rats, led to a rapid rise in the activity of hepatic adenyl cyclase that was 7(1/2) times greater than control values in 6 h. Cyclic AMP levels were also significantly increased above control values while the activity of cyclic nucleotide phosphodiesterase was unchanged. Hepatic alkaline phosphatase activity was increased 5(1/2) times above control in 12 h, but its rise followed that of adenyl cyclase and cyclic AMP by several hours. Cycloheximide inhibited the rise of hepatic alkaline phosphatase but not that of adenyl cyclase. The administration of glucagon, a known stimulator of hepatic adenyl cyclase, and of dibutyryl cyclic AMP, led to similar striking increases in hepatic alkaline phosphatase activity. This alkaline phosphatase increase was blocked by the prior administration of cycloheximide. Bile duct ligation, a known stimulator of hepatic alkaline phosphatase activity, failed to produce any significant changes in adenyl cyclase or cyclic AMP. Concomitant treatment of rats with bile duct ligation and cholera enterotoxin or bile duct ligation and glucagon, had no additive effect on the increase in hepatic alkaline phosphatase activity, although the increase occurred earlier. These results suggest that: (a) cyclic AMP may act as an inducer of hepatic alkaline phosphatase: (b) the stimulation of hepatic alkaline phosphatase by cholera enterotoxin is mediated by cyclic AMP; (c) the rise in hepatic alkaline phosphatase following bile duct ligation is not mediated by cyclic AMP; (d) the same alkaline phosphatase in rat liver may be induced by two (or more) mechanisms, only one of which requires cyclic AMP.
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PMID:Alkaline phosphatase. Possible induction by cyclic AMP after cholera enterotoxin administration. 435 3

Cholera and salmonellosis are two diarrheal diseases in which intestinal tissue cyclic adenosine monophosphate (cAMP) concentrations are elevated. Investigations of each experimental disease were initiated to identify the specific intestinal cells containing the elevated cAMP. Epithelial cells were eluted from the mucosa of infected and control intestinal loops of adult rabbits, after which the cAMP content of the epithelial cell fractions and the lamina propria cells was extracted and assayed. The identity of the epithelial cells (in the villus tip-to-crypt cell gradient) was monitored by measuring their intracellular alkaline phosphatase activity, while scanning electron microscopy was used to visualize the effects of infection and cell elution techniques. Clearly, in both experimental cholera and salmonellosis, elevated cAMP levels were associated with crypt epithelial cells. Villus tip epithelial cells from either infection tended to contain less cAMP than those of noninfected control tissue. In Salmonella-infected loops, it was apparent that cAMP was also elevated in lamina propria cell fractions. Lamina propria cells from V. cholerae-infected intestinal loops contained only basal levels of cAMP. In vitro exposure of isolated intestinal cells from normal rabbit intestine to a cell-free lysate of Salmonella resulted in elevation of cAMP in the epithelial cells and lamina propria cells. We conclude that in experimental cholera and salmonellosis, significant elevation of the cAMP levels occurred in intestinal crypt cells, consistent with an enterotoxin-mediated mechanism. In Salmonella-infected loops, it was unclear if the increased concentration of cAMP in lamina propria cells was generated by enterotoxin released from the invasive salmonellae or by prostaglandins formed during the inflammatory response to the bacteria, or by both mechanisms.
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PMID:Elevated cAMP in intestinal epithelial cells during experimental cholera and salmonellosis. 631 93

Arylsulfatase A, B and an anionic form of B were separated by DEAE-cellulose column chromatography from the brains of man, monkey, rabbit, rat and chicken. The relative proportion of brain arylsulfatases differed from one species to the other. The anionic form of arylsulfatase B was a minor component as compared to arylsulfatase A or B in human and monkey brains while it was a major component in rat and chicken brains. Anionic arylsulfatase B was found in fetal human brains and in newborn monkey brain. In the rat brain, the activities of arylsulfatases A and anionic B showed an increasing trend during development, reaching a peak around 20 days after birth, without any change in their proportions. Treatment with Escherichia coli alkaline phosphatase resulted in the conversion of a major portion (about 70%) of the anionic arylsulfatase B of human and monkey brains into a less charged form which remained unbound to DEAE-cellulose. This conversion by phosphatase was inhibited by inorganic phosphate. Rat and chicken brain anionic arylsulfatase B was not susceptible to alkaline phosphatase. Vibrio cholerae neuraminidase treatment did not significantly affect the charge on anionic arylsulfatase B from any of the species. The results suggested a phosphorylated form of anionic arylsulfatase B exclusively in the primate brain.
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PMID:Anionic forms of brain arylsulfatase B: evidence for a phosphorylated form in man and monkey. 668 Jun 91

The synthesis of alkaline phosphatase by two strains of Vibrio cholerae belonging to the Inaba and Ogawa serotypes has been examined in relation to the phosphate concentration of the culture medium. The synthesis of the enzyme in both strains was repressed in cells grown in the presence of a high concentration of inorganic phosphate. Lowering the phosphate content of the growth medium led to a derepression of enzyme activity. The presence of glucose in low phosphate medium stimulated the degree of derepression. The synthesis of the enzyme by strain Inaba 569B was more sensitive to inorganic phosphate than that of strain Ogawa 154. The enzyme was presumably located in the periplasmic space since it was released when the organisms were converted to spheroplasts.
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PMID:Repression of the alkaline phosphatase of Vibrio cholerae. 707 94

BeWo choriocarcinoma cells synthesize two alkaline phosphatase isoenzymes: germ-cell alkaline phosphatase and tissue-unspecific alkaline phosphatase. We have made use of the differential heat-stabilities of these two isoenzymes to study the induction of germ-cell alkaline phosphatase by sodium butyrate and cyclic AMP (cAMP). Sodium butyrate causes a large induction of germ-cell alkaline phosphatase activity (approx. 35-fold after 96 h) after an initial lag period of 12-24 h. We showed that butyrate increases germ-cell alkaline phosphatase mRNA. Dibutyryl cAMP also induces germ cell alkaline phosphatase (approx. 2.5-fold after 96 h). When optimal concentrations of butyrate and dibutyryl cAMP were added simultaneously to cells, they caused a synergistic induction of activity. This suggested that these compounds use separate mechanisms to induce germ-cell alkaline phosphatase activity and that it is the cAMP moiety of dibutyryl cAMP that induces enzyme activity. This was confirmed by the use of two additional cAMP analogues, 8-(4-chlorophenylthio) cAMP and 8-bromo cAMP, and of two compounds, 3-methyl-1-isobutylxanthine and cholera toxin, which raise the endogenous concentration of cAMP. All four compounds caused a 2-fold increase in enzyme activity. Treatment of cells with 8-(4-chlorophenylthio) cAMP, 8-bromo cAMP and cholera toxin increased germ-cell alkaline phosphatase mRNA between 2- and 7-fold. These data suggest that this alkaline phosphatase isoenzyme is regulated at the level of its mRNA by cAMP, in a manner distinct from that of butyrate.
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PMID:Induction of germ-cell alkaline phosphatase by butyrate and cyclic AMP in BeWo choriocarcinoma cells. 750 59


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