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)

Indices of calcium and phosphorus metabolism were studied in 3 children with osteopetrosis before and after infusion of bovine parathyroid hormone extract. Basal plasma concentrations of calcium, alkaline phosphatase and 25-hydroxy vitamin D tended to be low. Plasma immunoreactive PTH levels were at the upper normal range in two patients. A marked increase in urinary cyclic AMP in all patients was solely due to an increase in the nephrogenous cAMP. After vitamin D treatment urinary cAMP was essentially unchanged with the same preponderance of nephrogenous cAMP. Following PTH infusion plasma cAMP showed a brisk rise. There was also a prompt rise in urinary cAMP and a distinct decrease in the calcium to sodium clearance ratio indicating increased calcium reabsorption. Phosphaturic effect was only observed when PTH was given in the highest dose level. The findings are consistent with a state of low grade hyperparathyroidism which could not be related to the plasma levels of 25-hydroxy vitamin D or calcium.
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PMID:Acute response of parathyroid hormone in congenital osteopetrosis. 23 56

The postition of a number of human intestine brush border membrane enzyme activities in polyacrylamide gels after electrophoresis has been determined. These activities are, in order from the origin, maltase/glucoamylase, lactase/phlorizin hydrolase, maltase/sucrase/isomaltase, enteropeptidase, trehalase and gamma-glutamyl-transferase. Leucylnaphthylamide hydrolyzing activity was inactivated by sodium dodecylsulfate and its position was not determined. The positions of the activities have been correlated with the positions of protein bands previously determined. One such band situated between enteropeptidase and alkaline phosphatase has not been identified.
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PMID:Enzymes of the human intestinal brush border membrane. Identification after gel electrophoretic separation. 23 25

Extracts of adult Paramphistomum explanatum have been shown to contain high concentration of acid phosphomonoesterase with maximum activity at pH 4.5. The enzyme has been characterized by an exhibition of an unexpected increase in the inhibitory action of a mercury at 1 mM concentration by EDTA. With a lower concentration of mercury (0.1 mM and below) EDTA gave partial protection against inhibition. Different concentrations of magnesium and cobalt activated the enzyme while fluoride, copper, arsenate, tartrate and p-mercuribenzoate brought about inhibition. EDTA, glycine, glutathione and sodium azide had no effect. There was an indication of the presence of alkaline phosphomonoesterase at pH 10.0. The Km for p-nitrophenyl phosphate hydrolysis was 0.45 mM at pH 4.5.
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PMID:Phosphatase systems in Paramphistomum explanatum Fischoeder, 1901. 23 47

Callus calcifying cartilage alkaline phosphatase was resolved by DEAE-cellulose column chromatography into two distinct phsophatase activities. The phosphatase activity which was eluted first from the column, (phosphatase I), was active towards a variety of phosphate esters, sodium pyrophosphatase and several linear polyphosphates, while the second phosphatase activity , (phosphatase II), was active toward simple phosphate esters but not towards sodium pyrophosphate and linear oligo or polyphosphates. All the phosphate esters, sodium pyrophosphate and polyphosphates at higher concentrations were inhibitory for phosphatase I. The modulating effects of magnesium, calcium, zinc and other phosphatase modulators have been investigated. Both phosphatases from callus calcifying cartilage were found to be substrates of neuraminidase with sialic acid as the product. Besides the difference in their specificity, the phosphatases were found to be immunologically different and to have different molecular weights, strong indication that they are different enzymes.
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PMID:Resolution, purification and characterization of the orthophosphate releasing activities from fracture callus calcifying cartilage. 23 99

Improved histochemical techniques for the demonstration of NADP+-specific isocitrate dehydrogenase and malate dehydrogenase in tissue sections are described. With these techniques a semipermeable membrane is interposed between the incubating solutions and the tissue sections preventing diffusion of enzymes into the medium during incubation. In the histochemical system the NADP+-dependent enzymes catalyze the electron transfer from threo-Ds-isocitrate or L-malate into NADP+. Phenazine methosulphate and menadione serve as intermediate electron acceptors between reduced coenzyme and nitro-BT. Sodium-azide and amytal are incorporated into the incubating-medium to block electron transfer to the cytochromes. For demonstrating enzyme activities in sections containing non-specific alkaline phosphatase, a phosphatase inhibitor is added into the incubation media. Problems involved in the histochemical demonstration of both enzymes are discussed.
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PMID:Semipermeable membranes for improving the histochemical demonstration of enzyme activities in tissue sections. V. Isocitrate: NADP+ oxidoreductase (decarboxylating) and malate: NADP+ oxidoreductase (decarboxylating). 23 22

Pyridoxal-P reacts specifically with a single lysine residue at the active site of Escherichia coli aspartate transcarbamylase (Greenwell, P., Jewett, S. L., and Stark, G. R. (1973) J. Biol. Chem. 248, 5994-6001). Reduction of the Schiff base with sodium borohydride, succinylation of the remaining lysine residues, and digestion with trypsin result in formation of a single pyridoxyl peptide, which was purified to homogeneity after chromatography on DEAE-cellulose, treatment with alkaline phosphatase, and rechromatography. Amino acid composition and the results of limited sequential degradation showed that this peptide corresponds to residues 62 to 98 in the sequence of Konigsberg and co-workers, and contains 2 residues of lysine (Henderson, L., Roy, D., Martin, D., and Konigsberg, W., personal communication). By similar isolation, a second peptide was obtained from unsuccinylated catalytic subunit, containing only the pyridoxylated lysine, which corresponds to Lys-80. Derivatives of catalytic subunit containing an average of either one, two, or three pyridoxamine-P moieties per trimer have been prepared by reduction. These species, which retain catalytic activity in proportion to their unmodified active sites, were recombined with regulatory subunit to prepare partially modified derivatives of native aspartate transcarbamylase. At pH 8, fluorescence emission bands were observed at 340 nm, due to aromatic amino acids in the protein, and at 395 nm, due to the pyridoxamine-P moiety. Upon excitation at 280 nm energy transfer from protein to pyridoxamine-P was approximately 15%. The properties of the probe were used to study changes accompanying the binding of substrates and inhibitors. The effects of CTP and ATP were small. With the transition state analog N-(phosphonacetyl)-L-aspartate (PALA) or the substrate carbamyl-P, two types of response were observed. Derivatives of catalytic subunit and native enzyme which contain some unmodified sites and hence retain partial catalytic activity gave large increases in fluorescence at 395 nm. However, fully modified inactive derivatives gave much smaller increases. A derivative of native enzyme containing one triply modified and one unmodified catalytic subunit behaved like the other partially modified species. These results indicate that there is communication among the active sites of different catalytic trimers in modified native enzyme, as well as among active sites within the same modified catalytic trimer. The increases in fluorescence result from a red shift of the absorption maximum of the pyridoxamine-P moiety from 315 to 325 nm, which increases the absorbance at the excitation wavelength for fluorescence. At pH 7, the absorption spectrum is already shifted and, consequently, the binding of PALA and carbamyl-P has little effect on the fluorescence. Therefore, the binding of these compounds at pH 8.0 must cause a structural change in the protein, which in turn causes protonation of a group in the modified active sites, altering the spectral properties.
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PMID:Pyridoxal 5'-phosphate, a fluorescent probe in the active site of aspartate transcarbamylase. 23 51

The regenerating forelimb of the adult newt, Notophthalmus viridescens was investigated for 5'-nucleotidase (5' ribonucleotide phosphohydrolase, 3.1.3.5) acitivity. The newt's humeri were surgically removed, and after a twenty-one-day recovery period, the forelimbs amputated above the elbows. Regenerates were sampled at predetermined times for specific phases in the progress of regeneration, frozen, sectioned in a cryostat, and the sections fixed in 10% cold formol calcium. The Wachstein and Meisel [25] lead procedure at neutral pH was used predominately in these experiments, although tests were also conducted with Gomori's [14] calcium, Allen's [21] highly alkaline procedures. The substrates used to obtain specific enzyme reactions were adenine, cytosine, guanine, uracil and inosine 5'-monophosphate nucleotides. Sodium beta-glycerophosphate served as a non-specific phosphomonoesterase substrate, distilled water replaced substrate, and inhibitors such as zinc and cyanide ions were used as control measures to assist in increasing the precision in interpreting the results obtained. The most reactive 5'-nucleotidase (5'-Nase) loci were in the walls of the blood vascular system, mysial and neural sheaths, dermis, and periosteum: the principal cells involved were macrophages, endothelium of blood vessels, and fibrocytes of connective tissues. A moderate enzyme response was elicited from secretory cells of some of the subcutaneous glands, hypertrophied chondrocytes and osteogenic centers, chondrocytes in the articular regions and within red blood cells and leucocytes. Normal, injured and degenerating, or regenerating striated muscle and nerve fibers were judged unreactive for 5'-Nase. The epidermis and wound epithelium displayed negative responses for 5'-Nase. Cells forming the regeneration blastema were 5'-Nase reactive during the early formative phase, but with growth and development of the blastema into bulb and conic forms, these cells did not respond for this enzyme-activity. One suggestion offered is that the absence of 5'-Nase in cells of the blastema may be related to the lack of an adequate blood-vascular supply. Several functions of 5'-Nase in normal and regenerating tissues are discussed. A basic conclusion reached is that 5'-nucleotidase hydrolyses may be more involved in fundamental anabolic than in catabolic metabolism.
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PMID:Localization of 5'-ribonucleotide phosphohydrolase in regenerating (and normal) limb tissues of the adult newt Notophthalmus viridescens. 24 77

Minimal liver damage was induced in groups of rats by the administration of three toxicants, viz. carbon tetrachloride, sodium phenobarbitone and orotic acid. Serial blood samples were taken from the animals during the course of the experiment and the plasma levels of a number of enzymes, substrates and metabolites were measured. Liver and kidney samples were also taken at appropriate times after dosing and examined histologically for evidence of drug induced damage. The results of the experiment show that (I) no single test gave unequivocal evidence of liver damage for all three compounds, (II) the conventional liver function tests, alanine transaminase, aspartate transaminase, and alkaline phosphatase, whose plasma activities are usually reported in toxicity studies, were not the most sensitive indicators of the minimal liver cell damage caused by the drugs used in this experiment, (III) knowledge of the intracellular location of the diagnostic enzyme makes it possible to describe, at least in part, the nature of the changes within the liver, (IV) measurement of plasma cholesterol and triglyceride levels can provide information about disruption in lipid metabolism, (V) the times at which blood samples are taken are most important if transient drug effects on the liver are to be detected.
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PMID:Young Scientists Award Lecture 1977: An investigation into the value of some clinical biochemical tests in the detection of minimal changes in liver morphology and function in the rat. 27 87

Alkaline phosphatase (EC 3.1.3.1.) in developing teeth and in bone has been studied. Prior to hard tissue function a rather high enzyme activity was noted in differentiating odontoblasts, stratum intermedium, and outer enamel epithelium. A lower activity was observed in the cells of the dental papilla and stellate reticulum. After the onset of hard tissue formation the alkaline phosphatase activity was generally increased. Enzyme activity was also found in the proximal part of tall, secretory ameloblasts. In the short postsecretory ameloblasts a high enzyme activity was noted. At the onset of dentin mineralization there was an increase in enzyme activity in the cells of the subodontoblastic layer. In bone the highest alkaline phosphatase activity was found in osteoblasts. A difference was noted between the alkaline phosphatase of hard and soft tissues by means of the addition of inhibitors to the incubation media. Within the hard tissues it was possible to distinguish between two alkaline phosphatases after pretreatment with heat (56 degrees C) or the addition of specific inhibitors (sodium metavandate, ortho-and pyrophosphate). An isoenzyme which was sensitive to these procedures was demonstrated in odontoblasts and in the pulpal connective tissue. Another alkaline phosphatase isoenzyme, which was resistant to pretreatment with heat or the addition of vanadate or phosphate, was demonstrated in the subodontoblastic cell layer, stratum intermedium and the outer cells of the reduced enamel epithelium.
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PMID:Histochemical characterization of alkaline phosphatase in developing rat teeth and bone. 28 54

Changes in plasma sodium, potassium, chloride, total carbon dioxide, urea, creatinine, glucose, total bilirubin, iron, total protein, albumin, alkaline phosphatase (AP), aspartate amino transferase (AST), calcium, inorganic phosphorus, cholesterol and triglycerides were studied in 45 Thoroughbred foals 15 min to 28 days after birth. The results were analysed in 3 groups; Group 1 (0--12 h), Group 2 (12--36 h), Group 3 (1--4 weeks). When Group 2 was compared to Group 1, there were significant reductions of sodium, creatinine, iron and calcium and elevations of total protein and bilirubin. When Group 3 was compared to Group 1 there were significant reductions of sodium, chloride, urea, creatinine, bilirubin, iron and AP. Significant elevations occurred in glucose, total protein, AST, inorganic phosphorus and triglycerides.
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PMID:Plasma biochemistry changes in thoroughbred foals during the first 4 weeks of life. 28 40


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