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)

The roles of extracellular and intracellular mechanisms in the degradation of brush border proteins have been investigated by studying the small intestinal mucosa of dogs with naturally occurring exocrine pancreatic insufficiency. Peroral jejunal biopsies were homogenised and the organelles separated by isopycnic centrifugation on continuous sucrose density gradients. The distributions of marker enzymes for the principal subcellular organelles were determined in the gradients and related to the specific activities in the homogenates. There were increased activities of the brush border carbohydrases zinc-resistant alpha-glucosidase, maltase and sucrase in the pancreatic insufficient animals, but no change in lactase activity. The activity of gamma-glutamyl transferase was also higher in the affected group; the activities of two other brush border enzymes, alkaline phosphatase and leucyl-beta-naphthylamidase, however, were unaltered. These findings with an increase in the modal density of the brush border from 1.20 to 1.22 are consistent with an enhanced glycoprotein content of the microvillus membrane. There were also rises in the activities of lysosomal enzymes. N-Acetyl-beta-glucosaminidase activity was increased in the soluble fractions and the percentage latent enzyme activity was reduced, findings indicative of an increased fragility of the lysosomal membrane. There were no marked alterations in the activities or density gradient distributions of marker enzymes for the other organelles, stressing the specificity of the changes in the brush borders and lysosomes. These findings are compatible with the degradation of certain exposed brush border proteins by pancreatic proteases and suggest that when this is defective, intracellular degradative mechanisms may be stimulated.
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PMID:Biochemical changes in the jejunal mucosa of dogs with naturally occurring exocrine pancreatic insufficiency. 48 65

1. Fragments (2-20 mg wet wt.) of closed needle-biopsy specimens from human liver were disrupted in iso-osmotic sucrose and subjected to low-speed centrifugation. The supernatant was layered on a linear sucrose-density gradient in the Beaufay small-volume automatic zonal rotor. The following organelles, with equilibrium densities (g/ml) and principal marker enzyme shown in parentheses, were resolved: plasma membrane (1.12-1.14; 5'-nucleotidase); lysosomes (1.15-1.20; N-acetyl-beta-glucosaminidase); mitochondria (1.20; malate dehydrogenase); endoplasmic reticulum (1.17-1.21; neutral alpha-glucosidase); peroxisomes (1.22-1.24; catalase). 2. The distribution of particulate alkaline phosphatase and, to a lesser degree, leucine 2-naphthylamidase followed that of 5'-nucleotidase. gamma-Glutamyltransferase was associated with membranes of significantly higher equilibrium density than was 5'-nucleotidase. 3. The distribution of 12 acid hydrolases was determined in the density-gradient fractions. beta-Glucosidase had a predominantly cytosolic localization, but the other enzymes showed a broad distribution of activity throughout the gradient. Evidence was presented for two populations of lysosomes with equilibrium densities of 1.15 and 1.20 g/ml, but containing differing amounts of each enzyme. Further evidence of lysosomal heterogeneity was demonstrated by studying the distribution of isoenzymes of hexosaminidase and of acid phosphatase. 4. The resolving power of the centrifugation procedure can be further enhanced with membrane perturbants. Digitonin (0.12 mM) selectively disrupted lysosomes, markedly increased the equilibrium density of plasma-membrane components and lowered the density of the endoplasmic reticulum, but did not affect the mitochondria or peroxisomes. Pyrophosphate (15 mM) selectively lowered the equilibrium density of the endoplasmic reticulum.
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PMID:Analytical subcellular fractionation of needle-biopsy specimens from human liver. 70 96

At 20 degrees C, aflatoxin B1, at a sublethal dose, decreases the activity of alkaline phosphatase (EC 3.1.3.1), alpha-glucosidase (EC 3.2.1.20), esterase (EC 3.1.1.1), chymotrypsin (EC 3.4.21.1), leucine aminopeptidase (EC 3.4.11.1), and phosphoamidase (EC 3.9.1.1) biosynthesis in Bacillus thuringiensis (Berliner). In contrast, at 41 degrees C no significant decrease was observed. At this temperature, the mycotoxin is not destroyed or metabolized and bacterial cells are resistant to the toxin.
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PMID:[Effect of aflatoxin B1 on the enzymatic activities of Bacillus thuringiensis (Berliner)]. 88 28

A subcellular fractionation method to isolate simultaneously apical and basolateral plasma membrane fractions from the human adenocarcinoma cell line Caco-2, grown on filter supports, is described. The method employs sucrose-density-gradient centrifugation and differential precipitation. The apical membrane fraction was enriched 14-fold in sucrase-isomaltase and 21-fold in 5'-nucleotidase compared with the homogenate. The basolateral membrane fraction was enriched 20-fold relative to the homogenate in K(+)-stimulated p-nitrophenylphosphatase. Alkaline phosphatase was enriched 15-fold in the apical membrane fraction and 3-fold in the basolateral membrane fraction. Analytical density-gradient centrifugation showed that this enzyme was a true constituent of both fractions, and experiments measuring alkaline phosphatase release following treatment with phosphatidylinositol-specific phospholipase C showed that in both membrane fractions the enzyme was glycosyl-phosphatidylinositol-linked. There was very little contamination of either membrane fraction by marker enzymes of the Golgi complex, mitochondria or lysosomes. Both membrane fractions were greater than 10-fold purified with respect to the endoplasmic reticulum marker enzyme alpha-glucosidase. Protein composition analysis of purified plasma membrane fractions together with domain-specific cell surface biotinylation experiments revealed the presence of both common and unique integral membrane proteins in each plasma membrane domain. The post-synthetic transport of endogenous integral plasma membrane proteins was examined using the devised subcellular fractionation procedure in conjunction with pulse-chase labelling experiments and immunoprecipitation. Five common integral membrane proteins immunoprecipitated by an antiserum raised against a detergent extract of the apical plasma membrane fraction were delivered with the same time course to each cell-surface domain.
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PMID:The post-synthetic sorting of endogenous membrane proteins examined by the simultaneous purification of apical and basolateral plasma membrane fractions from Caco-2 cells. 131 18

This study examines the effects of an enteropathogenic Escherichia coli on microvillar membrane proteins during organ culture of rabbit ileal explants. Explants maintained with enteropathogenic E coli showed brush border effacement affecting approximately 50% of enterocytes, and where enteropathogenic E coli were closely adherent to the enterocyte surface microvilli were apparently being shed as vesicles. The microvillar membrane enzymes alkaline phosphatase, aminopeptidase N and alpha-glucosidase were released into the culture medium during organ culture, and this process was significantly enhanced by enteropathogenic E coli. This increased loss of microvillar membrane enzymes into the culture medium was associated with decreased tissue activities of microvillar membrane enzymes in enteropathogenic E coli infected ileal explants compared with control. For aminopeptidase N in particular, however, total enzyme activities in the tissue plus culture medium were increased comparing enteropathogenic E coli with control, suggesting that there might be an increase in the rate of synthesis of certain microvillar membrane proteins. Reorientating sucrose density gradient centrifugation of culture medium showed that alkaline phosphatase, aminopeptidase N and alpha-glucosidase were predominantly associated with particles of peak modal density 1.19 g/ml in both groups, confirming that enteropathogenic E coli accelerate release of microvillar membrane enzymes as vesicles. Analytical fractionation of ileal explants showed that enteropathogenic E coli resulted in a loss of microvillar membrane enzyme activities from the main brush border peak of modal density 1.21 g/ml present in controls. The density of the remaining smaller and lighter peak increased from 1.19 g/ml to 1.23 g/ml after homogenisation in digitonin, confirming association of these proteins with cholesterol containing membranes and not endoplasmic reticulum. These findings suggest that enteropathogenic E. coli accelerate the normal shedding of microvillar membrane proteins as vesicles, and may stimulate a compensatory increase in microvillar membrane protein synthesis.
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PMID:Effects of enteropathogenic Escherichia coli on microvillar membrane proteins during organ culture of rabbit intestinal mucosa. 135 65

Diversion of portal blood in congenital portosystemic shunts (CPSS) results in liver atrophy and passage of toxins into the systemic circulation causing hepatic encephalopathy. In some dogs, there is indirect evidence for hepatic insufficiency, but histologic findings are equivocal. This study determined whether hepatocyte integrity in PSS is comprised at a subcellular level using analytical subcellular fractionation of liver biopsies. Six dogs with CPSS had hypoproteinemia (6/6), increased serum alkaline phosphatase (6/6) and alanine aminotransferase (4/6) activity, hypocholesterolemia (6/6), and decreased blood urea (2/6). Liver biopsy specimens had increased activities (mU/mg protein) of alkaline phosphatase (17.9 +/- 10.1; controls 5.1 +/- 5.3: P less than 0.01), but not of other plasma membrane enzymes. There were increased activities of endoplasmic reticular (neutral alpha-glucosidase: 1.67 +/- 0.7; controls 0.86 +/- 0.2: P less than 0.01) and lysosomal enzymes (N-acetyl-beta-glucosaminidase: 12.6 +/- 2.3; controls 6.24 +/- 2.7: P less than 0.01; alpha-mannosidase: 0.85 +/- 0.5; controls 0.39 +/- 0.3: P less than 0.05). Subcellular fractionation on reorientating sucrose density gradients showed a high-density peak of alkaline phosphatase suggestive of a specific increase in the biliary canalicular component of enzyme activity. Neutral alpha-glucosidase was shifted to denser fractions, indicative of an increase in the proportion of rough-to-smooth endoplasmic reticulum and consistent with enhanced synthesis of membranous enzymes. There was also evidence for increased fragility of intracellular organelles, particularly lysosomes. In contrast, histology showed either no abnormalities or minor degenerative changes compatible with hepatic underperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hepatic organelle pathology in dogs with congenital portosystemic shunts. 161 98

The present work investigates the ability of galactose to affect enterocyte differentiation during normal development in vivo. Energy intake has also been varied to take account of the fact that galactose is poorly metabolized in mice. Brush-border lactase, alpha-glucosidase, dipeptidylpeptidase-IV, aminopeptidase N, alkaline phosphatase and microvillus length were measured as markers of enterocyte differentiation in mice fed diets containing galactose (G diet), corn oil (E diet) or galactose + corn oil (G + E diet). Maintaining mice on a G instead of E diet reduced brush-border lactase activity and enterocyte migration rates; alpha-glucosidase, dipeptidylpeptidase-IV, aminopeptidase N and microvillus length expression increased and alkaline phosphatase activity remained unchanged. Feeding the G + E diet restored enterocyte migration rates, lactase, aminopeptidase N and dipeptidylpeptidase-IV activities to values found in mice fed the E diet. Galactose stimulation of alpha-glucosidase and microvillus length expression was, however, fully maintained in mice fed the G + E diet. Present results show that enterocyte differentiation is affected independently by varying dietary galactose and energy levels; that galactose effects always increase and energy effects usually decrease expression of enterocyte components and that energy stimulation of lactase activity is exceptional.
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PMID:Galactose effects on enterocyte differentiation in the mouse jejunum. 190 92

Multidimensional scaling (MDS) was applied to the numerical taxonomy of Candida species based on isoenzyme profiles. Multidimensional scaling uses proximity measures to generate a spatial configuration of points in multidimensional space where distances between points reflect similarity among types. The biochemical profiles of 35 types of Candida species based on 26 tests consisting of isoenzymes of alpha-glucosidase, alkaline phosphatase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and superoxide dismutase were analyzed. Cluster analysis of MDS, using the Euclidean distance as a proximity measure, separated C. tropicalis and C. paratropicalis from C. albicans and C. stellatoidea. Stepwise multiple linear regression revealed the isoenzyme tests which influenced each of the MDS dimensions. MDS was able to reduce the dimensionality of the test profile.
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PMID:Application of multidimensional scaling in numerical taxonomy: analysis of isoenzyme types of Candida species. 202 78

A series of proteins (albumin, transferrin, alpha 1-antitrypsin, alpha-fetoprotein and pancreatic oncofetal antigen) and enzymes (gamma-glutamyltranspeptidase, aminopeptidase M, alkaline phosphatase, alpha-glucosidase and protease) was measured in fetal meconium extracts. There were 19 fetuses thought to have cystic fibrosis (CF), 13 with neural tube defects, three with chromosome abnormalities and 19 normal controls, all with gestational ages between 18 and 21 weeks. With the exception of alpha-fetoprotein, all the proteins and enzymes were significantly elevated in the CF meconium extracts. The most definitive indicator of a CF fetus was the albumin concentration, where the mean level was five times that found in the control groups. However, five of 19 fetuses assumed to have CF had albumin in the normal range. In these cases the meconium protease levels were grossly elevated. Furthermore, in the same five fetuses meconium concentration of pancreatic oncofetal antigen, a protein synthesized in the fetal pancreas, was also greatly raised. We suggest that post-mortem examination of a fetus thought to have CF should include measurement of meconium albumin, protease and pancreatic oncofetal antigen.
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PMID:Biochemical analysis of meconium in fetuses presumed to have cystic fibrosis. 242 27

Since they are found to be increased in lesions of acute necrotic ulcerative gingivitis or marginal periodontitis, agents for these diseases. In the present study, 38 pure cultured strains were obtained as a result of isolation and culture of samples collected from lesions of marginal periodontitis (periodontal pokets), and the biological and biochemical characteristics of these strains were investigated. 1) Light microscopy (including dark-field microscopy) and transmission electron microscopy (negative staining) were used for observation of the morphology and cellular structure of the strains. The cells had a spiral shape, and showed active movement. Based on the above findings the cultured strains were all confirmed to be spirochetes of small to medium size, being 0.08-0.24 micron in width. 2) Growth and motility of the strains were investigated on various types of culture medium. Intense growth and movement were noted in strains cultured in bovine liver exudate medium containing horse serum (pH 7.2) at 37 degrees C under anaerobic conditions produced by the evacuation-replacement method (95% N2, 5% CO2) for 3-7 days after inoculation. 3) Thirty-five strains were positive for indole production and decomposition of urea, mucin, hippuric acid and esculin. Production of hydrogen sulfied was observed in 31 strains. In decomposition tests for 17 carbohydrates, 17 strains were positive for galactose and 14 strains were positive for glucose, while 11 strains were positive for dextrin and 10 strains for fructose upon decomposition of soluble starch. Other carbohydrates were also decomposed by a few strains. 4) In an investigation of the production of alcohol and lower fatty acids, among the metabolic products detected by gas chromatography, a large amount of acetic acid and small amounts of ethanol, lactic acid, propionic acid, pyruvic acid were observed. 5) The results of enzyme activity tests using an API ZYM system indicated relatively high activities of esterase, esterase-lipase, alpha-glucosidase, alkaline phosphatase, trypsin and acid phosphatase.
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PMID:[Biological and biochemical characteristics of the oral spirochetes isolated from the focus of marginal periodontitis]. 276 48


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