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 localization of ATPases in 7 osteogenic sarcomas of osteoblastic, chondroblastic and fibroblastic type was investigated at the fine structural level using two types of substrates: one with lead as capturing ion and one with strontium (the latter presumed to reveal sites of Na+-K+-dependent transport ATPase). Reaction product with the lead-ATP medium was located on the plasma membrane and the membranes bordering subjacent vesicles and vacuoles in all the various types of osteoblastlike and fibroblastlike cells and also in types 1 and 3 chondroblastlike cells, and multinucleated giant cells believed to be neoplastic. Furthermore, deposits of reaction product were demonstrated in lysosomelike organelles in all the aforementioned cells. Except in the case of chondroblastlike cells, precipitates marking the localization of enzyme were confined to areas of the plasma membrane where adjacent cells were closely applied (the free surface lacked precipitates). In chondroblastlike cells the reaction product was usually deposited along the whole plasma membrane. Presence of L-Homoarginine or L-Tetramisole in the incubation medium in concentrations that have been shown to completely abolish alkaline phosphatase activity did not affect the occurrence of the reaction product with ATP as substrate indicating that the enzyme hydrolysing ATP was substrate-specific. Reaction product marking sites of Na+-K+-dependent ATPase was confined to plasma membranes and lysosomes of cells in vessel walls. The observations strengthen the notion obtained in studies on the localization of alkaline phosphatase, namely that osteoblastlike, chondroblastlike, and fibroblastlike cells in osteogenic sarcomas are histogenetically related to one another and to those multinucleated giant cells that presumably are of a neoplastic nature.
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PMID:Human osteogenic sarcoma: fine structural localization of adenosine triphosphatase. 300 94

This paper is an attempt to the analysis of the main biochemical characteristics of alkaline phosphatase from sheep polymorphonuclear neutrophils. Ten male adult Romanoff X Berrichon sheep were studied. Alkaline phosphatase was analyzed from cell homogenates, after extraction and solubilization steps. The Vmax and Km values for 4-nitrophenylphosphate at pH = 9.80 were 347.3 +/- 34 IU/ml and 0.7 +/- 0.18 mmol/l, respectively. The pH optimum was 9.80 with 4-nitrophenylphosphate. L-Homoarginine and EDTA, but not L-phenylalanine, inhibited the enzyme. Magnesium above a concentration of 0.5 mmol/l has shown a protective effect against inhibition by 115, 156 and 250 mmol/l urea (final concentration). Sheep neutrophil alkaline phosphatase was found to be very heat-labile. Polyacrylamide gel electrophoresis indicated a single band of activity with a relative mobility similar to that of the slow component of bone and liver isozymes. It is suggested from the above results that sheep neutrophil alkaline phosphatase shares several biochemical properties similar to those of hepatic bone tissue isozyme.
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PMID:Characterization of alkaline phosphatase in polymorphonuclear neutrophils from normal sheep. 323 20

Thermostability of the purified alkaline phosphatase derived from human uterine muscle and myoma was established before and after desialization. Both enzymes were inhibited by sucrose, glucose and maltose in proportion to the carbohydrate concentration. L-Homoarginine inhibits the myoma enzyme in 90%, L-leucine, L-histidine and L-tryptophan in about 60%, and L-phenylalanine in less than 15%. The type of inhibition and Ki values were determined. Muscle and myoma enzymes cross-reacted with antisera against human liver and placental isoenzymes. Molecular and kinetic properties of the enzyme were compared with known human isoenzymes of alkaline phosphatase.
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PMID:Alkaline phosphatase from human uterine myoma. II. Kinetic and immunological properties. 398 59

An organ-specific alkaline phosphatase inhibitor, L-homoarginine, at 44.5 mM concentration inhibited [3H]thymidine uptake by C3H/He mouse osteosarcoma (OS) cells, while L-arginine, L-phenylalanine, and glycine had little effect on the uptake. This inhibitory effect of L-homoarginine persisted even after the cells were washed free of the amino acid with fresh media. L-Homoarginine did not affect [3H]thymidine uptake by mouse myeloma MOPC 104E cells. In long-term culture, 22.3 mM L-homoarginine inhibited proliferation of OS cells. L-Arginine at the same concentration inhibited the proliferation to a lesser extent. On the other hand, L-phenylalanine and glycine did not affect in vitro proliferation of OS cells. When the same number of viable OS cells was inoculated s.c. after culturing the 24 hr with 44.5 mM L-homoarginine or L-arginine, the tumor growth in mice given injections of L-homoarginine (but not L-arginine)-treated cells was delayed markedly. Electron microscopic studies indicated that the inhibiting effect on OS cell proliferation was associated with a marked increase in lysosomal granules and a decrease in virus-like structures. Similarly, biochemical assay for acid phosphatase of cell homogenates demonstrated a 2-fold increase of activity in L-homoarginine-treated cells when compared to controls and L-arginine-treated cells. Thus, L-homoarginine inhibits proliferation and alkaline phosphatase activity of mouse OS cells and appears to increase acid phosphatase activity in synthesis of lysosomal granules.
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PMID:Inhibitory effect of L-homoarginine on murine osteosarcoma cell proliferation. 617 11

The sensitivity of the dental pulp enzyme to heat was similar to that of enzymes from bone and kidney; alkaline phosphatases from liver and intestine were more stable to heat. L-Homoarginine strongly inhibited the enzyme activities from pulp, bone, kidney and liver but did not affect intestinal enzyme activity. Increasing the molarity of carbonate buffer or glycine buffer in the assay solution decreased intestinal alkaline phosphatase activity more markedly than enzyme activities of other tissues. In 100 mM glycine-NaOH buffer, the effects of Zn2+, Mg2+ and Ca2+ on pulp alkaline phosphatase activity were similar to those on the enzyme activities of bone, kidney and liver. The electrophoretic pattern of the pulp enzyme on sodium dodecyl sulphate-gels was identical with that of bone enzyme and differed from the patterns of enzymes from other tissues. These results suggest that the dental pulp alkaline phosphatase may be the same as bone enzyme.
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PMID:A comparison of the alkaline phosphatases of rat dental pulp, bone, kidney, liver and intestine. 619 45

Human seminal alkaline phosphatase was investigated with respect to its electrophoretic mobility, heat lability, and susceptibility to inhibition by phenylalanine, tartrate, and homoarginine. Total alkaline phosphatase activity in 30 samples of human semen was measured colorimetrically, using p-nitrophenylphosphate as substrate. Using linear regression analysis, no significant correlation was found between the enzyme activity and the sperm count, sperm motility, semen volume, and the concentrations of seminal inositol and fructose. The alkaline phosphatase activity was higher in the earlier portion of split ejaculate samples. Sodium DL-tartrate (42 mmol/l), which inhibits acid phosphatase, did not inhibit seminal alkaline phosphatase significantly. L-Homoarginine (10 mmol/l), an inhibitor of the liver and bone isoenzymes, inhibited the seminal enzyme (53%), whereas L-phenylalanine (12 mmol/l), a strong inhibitor of placental alkaline phosphate, decreased activity by about 10%. Electrophoresis of semen samples on agarose revealed a broad band which was not sharpened after treatment with neuraminidase. Semen total alkaline phosphatase was essentially totally inactivated by heating at 56 degrees C for 15 min or 10 min at 65 degrees C; similar behaviour has been reported for the liver and bone isoenzymes. Electrophoresis after heating did not reveal a residual band of heat-stable placental-like alkaline phosphatase. Semen alkaline phosphatase appears to contain more than one isoenzyme, but placental-like alkaline phosphatase cannot be more than a minor component.
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PMID:Alkaline phosphatase in human semen: an investigation using enzyme inhibitors and gel electrophoresis. 813 13