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

---

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

Adenylate cyclase from rat hippocampus was separated by electrophoresis in polyacryl amide microgels and stained for enzymatic activity using a new histochemical procedure. This method involves the use of AMP-PNP, aminophylline, dithiotreitole, and Sr2+ as "primary" capture ions, thus fulfilling all the demands for a really specific histochemical incubation medium for the enzyme. The incubation of the gels with this medium resulted in the inhibition of other enzymes, which are capable of splitting AMP-PNP (ATP: pyrophosphatase, alkaline phosphatase), whereas adenylate cyclase remained highly active under these conditions. The enzyme was found to be present in two forms in the gels. Both protein bands were stimulated by the addition of various biogenic amines to the incubation medium. One protein band was fully GMP-PNP dependent in its activity. It is reasonable to suppose that these forms are either differently high aggregated molecules of the enzyme or enzyme molecules bound to their regulatory sites.
...
PMID:Specific demonstration of rat brain adenylate cyclase in polyacryl amide microgels by a new histochemical procedure. 732 48

The effect of stannous chloride on bone metabolism was examined in weanling male rats given oral dose of 1.0 mg Sn/kg at 12-h intervals for 28 days. Tin administration produced progressive increase in tin content of the femoral diaphysis and epiphysis. Calcium content in the femoral epiphysis but not diaphysis was significantly decreased by tin administration for 28 days, while inorganic phosphorus contents in the femoral diaphysis and epiphysis were not changed significantly. Acid and alkaline phosphatase activities in the femoral diaphysis and epiphysis were markedly reduced by tin administration for 3 days, and significant decreases in the femoral epiphysis were also observed at 28 days. Meanwhile, ATPase and pyrophosphatase activities in the femoral diaphysis and epiphysis were not altered significantly by tin administration. From the present study, of mineral composition and its related enzyme activity, the decreases of acid and alkaline phosphatase activities in the femoral epiphysis were regarded as the biochemical manifestation of the toxic action of inorganic tin.
...
PMID:Changes in mineral composition and its related enzyme activity in the femur of rats orally administered stannous chloride. 732 88

The effect of sodium pentosan polysulphate (SPP) was investigated in calcium oxalate stone forming rats with respect to the urinary excretion of certain risk factors and enzymes. Calcium oxalate stones were induced by feeding 3% w/w sodium glycollate to the rats. Urinary calcium, oxalate, phosphorus and uric acid levels were increased in stone formers. In contrast magnesium excretion was low in this group. SPP treatment lowered oxalate and calcium levels in both controls and experimental animals. Magnesium levels were increased moderately. Increased excretion of urinary enzymes--LDH, alkaline phosphatase, gamma-GT and beta glucuronidase--in calculogenic rats indicates membranuria and damage to proximal tubules during stone formation. Decreased pyrophosphatase activity was observed in glycollate fed rats. SPP treatment decreased the excretion of the above enzymes in the treated groups. Stone formers exhibited decreased LAP and fibrinolytic (urokinase) activities. SPP being associated with fibrinolytic properties, increased the activities of the above two enzymes to that of control levels in calculogenic rats.
...
PMID:Alterations in some risk factors and urinary enzymes in urolithiatic rats treated with sodium pentosan polysulphate. 768 93

The functional morphology of the Golgi apparatus was studied in various types of cells in the rat endometrium during the oestrous cycle. A cerium-based enzyme-cytochemical method was used for the ultrastructural visualization of the activity of thiamine pyrophosphatase (TPPase). The cerium-based method was evidently superior to the classical lead technique, which was used for comparison. TPPase activity in luminal and glandular epithelial cells displayed cyclical modulation and redistribution. It was restricted to only one or two narrow trans lamellae during dioestrus but extended during proestrus and oestrus into nearly all trans-to-cis lamellae of the well-compartmentated Golgi apparatus. A homogeneous staining reaction, which was particularly intense during the latter two phases and only partly due to unspecific alkaline phosphatase, was confined to the apical and basolateral plasma membranes of luminal epithelial cells. In the stromal fibroblasts, only one short Golgi saccule was positive at dioestrus, whereas three or more trans Golgi lamellae were filled with reaction product during oestradiol-dominated oestrus. TPPase activity was furthermore observed in the lysosomes in epithelial cells, stromal fibroblasts, capillary endothelial cells and pericytes. The present findings of cyclic changes in TPPase activity in epithelial cells and stromal fibroblasts provide the first evidence of cyclic modulation and redistribution of this enzyme in the endometrium.
...
PMID:Thiamine pyrophosphatase cytochemistry in rat endometrium during the oestrous cycle. 782 14

The effects of some protein kinase effectors on phosphohydrolase and transport activities of yeast vacuoles have been studied. The platelet-activating factor (PAF), a plant vacuolar protein kinase C stimulator, had a protonophoric and membrane-damaging effects on yeast vacuoles and inhibited the ATP-dependent delta mu H+ formation and ATP-dependent secondary transport but stimulated the ATPase and pyrophosphatase hydrolase activities by abrogating proton control. PAF increasing the tonoplast permeability for the corresponding substrates also stimulated pyrophosphatase, polyphosphatase and alkaline phosphatase activities. Lysolipid sphingosine, a plant vacuolar protein kinase C inhibitor, poorly stimulated the ATPase activity and the ATP-dependent formation of Em in isolated yeast vacuoles, while the pyrophosphatase activity increased by 200%. Other hydrolase activities tested were insensitive to the effect of the lysolipid. Sphingosine inhibited the ATP-dependent citrate transport only insignificantly. Heparin, an effective casein kinase inhibitor, suppressed the ATPase and polyphosphatase activities in isolated yeast vacuoles. The polyphosphatase activity was inhibited both in the vacuolar sap and the tonoplast solubilized by a Zwittergent TM-314, in contrast with the ATPase activity which was inhibited by heparin only in isolated vacuoles. Heparin is suggested to inhibit polyphosphatase by directly influencing the enzyme.
...
PMID:[The effect of PAF, sphingosine and heparin on certain phosphohydrolase and transport activity of yeast vacuoles]. 794 17

We demonstrated that polyamines, such as spermine and spermidine, can enhance the pyrophosphatase (PPase) activity of alkaline phosphatase (ALP). Bisphosphonates such as disodium-1-hydroxy-1-aminopropylidine-1,1-diphosphonate (APD) and ethane-1-hydroxy-1,1'-diphosphonate (HEDP) inhibited ALP phosphate ester hydrolysis activity more than PPase activity at the same concentrations. This indicated that PPase activity of ALP was available in the presence of pyrophosphate analogues and possibly organic pyrophosphates as well. Vanadate and cadmium inhibited ALP and PPase activity more than ALP phosphate ester hydrolysis activity at the same concentrations. Calcium inhibited ALP PPase activity, though it did not inhibit ALP phosphate ester hydrolysis activity. At high concentrations, ascorbic acid slightly inhibited ALP PPase activity, though it did not inhibit ALP phosphate ester hydrolysis activity. ALP PPase activity appeared to have ubiquitous intracellular existence, broad substrate specificity and extensive interaction with calcium, vanadium and polyamines-substances which are important for cell metabolism and cell growth. These findings suggested that intracellular ALP modulated cell metabolism and cell growth by its PPase activity.
...
PMID:[Implications of alkaline phosphatase pyrophosphatase activity: intracellular functions of alkaline phosphatase]. 807 80

We have devised a method to replace the cap structure of a mRNA with an oligoribonucleotide (r-oligo) to label the 5' end of eukaryotic mRNAs. The method consists of removing the cap with tobacco acid pyrophosphatase (TAP) and ligating r-oligos to decapped mRNAs with T4 RNA ligase. This reaction was made cap-specific by removing 5'-phosphates of non-capped RNAs with alkaline phosphatase prior to TAP treatment. Unlike the conventional methods that label the 5' end of cDNAs, this method specifically labels the capped end of the mRNAs with a synthetic r-oligo prior to first-strand cDNA synthesis. The 5' end of the mRNA was identified quite simply by reverse transcription-polymerase chain reaction (RT-PCR).
...
PMID:Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides. 812 98

There is little information concerning the intracellular function of inositol 1,3,4,5,6-pentakis- and hexakisphosphate, despite their being the most abundant inositol polyphosphates. Current opinions that they play passive roles as antioxidants (Graf, E., Mahoney, J. R., Bryant, R. G., and Eaton, J. W. (1987) J. Biol. Chem. 259, 3620-3624) or "housekeeping" molecules (Berridge, M. J., and Irvine, R. F. (1989) Nature 341, 197-205) arises from belief in their metabolic lethargy. However, we have discovered that cell homogenates, incubated with 5 mM fluoride and 5 mM ATP, converted both inositol hexakisphosphate (Km = 2 +/- 0.5 microM, Vmax = 9 +/- 2 pmol/mg of protein/min) and inositol 1,3,4,5,6-pentakisphosphate (Km = 13 +/- 4 microM, Vmax = 11 +/- 5 pmol/mg of protein/min) to more polar products. These reactions were also observed in intact cells treated with 0.5-20 mM fluoride, and the precursor/product relationships were confirmed by comparing the effects of fluoride on cells differentially labeled with [3H]inositol in either short-term or pulse-chase protocols. The novel products were determined to be inositol pyrophosphates because of their relatively specific hydrolysis by tobacco pyrophosphatase and alkaline phosphatase. The pyrophosphates were metabolized rapidly by cell homogenates back to their pentakisphosphate and hexakisphosphate precursors. This endogenous pyrophosphatase activity was inhibited by up to 99% by 5 mM fluoride in vitro. In intact cells incubated with 10 mM fluoride, about 20% of the inositol 1,3,4,5,6-pentakisphosphate pool, and 50% of the inositol hexakisphosphate pool were each converted to pyrophosphate derivatives within 1 h.
...
PMID:Turnover of inositol polyphosphate pyrophosphates in pancreatoma cells. 838 79

The substrate specificity of the cyanobacterial dual-specificity protein phosphatase, IphP, was explored using a variety of potential substrates. The enzyme displayed phosphomonoesterase activity toward a broad range of peptide, protein, and low molecular weight organophosphate compounds. It displayed little or no hydrolase activity toward phosphodiesters, phosphoramides, carboxyl esters, or sulfoesters. However, it did display measurable pyrophosphatase activity, especially toward ADP and ATP. Among the low molecular weight phosphomonoesters, the presence of an aromatic ring either as part of the leaving group alcohol or immediately adjacent thereto, as in 5'-AMP, was a strong positive determinant for hydrolysis. Among peptide and protein substrates, a rough, but imperfect, correlation between charge character and hydrolysis was noted in which proteins and phosphorylation sites of an acidic nature seemed favored. Heparin affected IphP activity in a substrate-dependent manner. Toward small organophosphates, heparin had no significant effect, but it was inhibitory toward most protein and peptide substrates. However, toward phosphoseryl casein and MAP kinase, it enhanced activity as much as 10-fold. This enhancement was attributed to the ability of heparin to bind to these substrate proteins, as well as IphP, and recruit them to the same microenvironment.
...
PMID:Substrate specificity of IphP, a cyanobacterial dual-specificity protein phosphatase with MAP kinase phosphatase activity. 865 37

Purified membrane-bound alkaline phosphatase from rat osseous plate hydrolyzed pyrophosphate in the presence of magnesium ions, with a specific activity of 92.7 U/mg. Optimal apparent pH for pyrophosphatase activity was 8.0 and it remained unchanged on increasing the pyrophosphate concentration. In the absence of magnesium ions the enzyme had a Km = 88 microM and V = 36.7 U/mg for pyrophosphate and no inhibition by excess substrate was observed. Pyrophosphatase activity was rapidly destroyed at temperatures above 40 degrees C, but magnesium ions apparently protected the enzyme against denaturation. Sodium metavanadate (Ki = 1.0 mM) was a competitive inhibitor of pyrophosphatase activity, while levamisole (Ki = 8.2 mM) and theophylline (Ki = 7.4 mM) were uncompetitive inhibitors. Magnesium ions (K0.5 = 1.7 microM) stimulated pyrophosphatase activity, while cobalt (Ki = 48.5 microM) and zinc (Ki = 22.0 microM) ions were non-competitive inhibitors. Manganese and calcium ions had no effect on pyrophosphatase activity. The Mw of the pyrophosphatase protein was 130 kDa by gel filtration, but a value of 65 kDa was obtained by dissociative gel electrophoresis, suggesting that it was a dimer of apparently identical subunits. These results suggested that pyrophosphatase activity stems from the membrane-bound osseous plate alkaline phosphatase and not from a different protein.
...
PMID:Inorganic pyrophosphate-phosphohydrolytic activity associated with rat osseous plate alkaline phosphatase. 959 80


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---