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)

At least three gluconic acid forming enzymes were identified in cell-free extracts of Aspergillus niger: glucose oxidase (EC 1.1.3.4), a glucose dehydrogenase (EC 1.1.99.10), and an enzyme or a mixture of enzymes catalyzing the cleavage of 6-phosphogluconate into gluconate and inorganic phosphate. 2,6-dichlorphenolindophenol was one of the hydrogen acceptors in vitro of the glucose dehydrogenase. Some properties of this enzyme (Km values, pH-dependence, substrate and hydrogen acceptor specificity), as determined in cell-free extracts, were found to be in good agreement with properties described in literature for a glucose dehydrogenase which has been purified from Aspergillus oryzae. The formation of Pi from 6-phosphogluconate and other phosphate esters was found to have an optimum between pH 7 and 8 , and another below pH 4. This suggests that it is catalyzed by an alkaline and an acid phosphomonoesterase (EC 3.1.3.1, 3.1.3.2), both enzymes exhibiting only low substrate specificity. The influence of extraction and assay buffers on the activity of gluconate forming enzymes was investigated. Loss of activity during preparation of cell-free extracts, as calculated from loss of activity storage of cell-free extracts at 4 degrees C, was found to be lower than 4%. Purified glucose oxidase added before homogenization was found in the extract almost quantitatively.
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PMID:[Gluconic acid forming enzymes in Aspergillus niger (author's transl)]. 1 16

Plasma membranes were isolated from the livers of control and Streptococcus pneumoniae-infected rats. This work, therefore, represents the first isolation of plasma membranes from infected actron microscopy and by the use of enzyme markers for microsomes (glucose-6-phosphatase), mitochondria (glutamate and malate dehydrogenases), and lysosomes (acid phosphatase). Plasma membranes from infected cells banded at the same sucrose density as plasma membranes from uninfected cells. Moreover, equivalent amounts of plasma membranes could be isolated from control and infected rat livers. There were, however, significant alterations in the enzyme complement of the plasma membrane after infection. 5'-Nucleotidase activity was significantly decreased, whereas alkaline phosphatase activity was significantly increased. Kinetic analysis demonstrated that only the Vmax and not the Km of these two enzymes was changed, suggesting that the altered affinity of the enzymes for substrate was not the mechanism responsible for the observed alterations. No change in the mitochondrial enzyme markers was observed after infection, but the specific activity of microsomal glucose-6-phosphatase decreased significantly. Possible explanations for the observed alterations are discussed.
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PMID:Isolation and partial characterization of plasma membranes from the livers of control and Streptococcus pneumoniae-infected rats. 1 27

1. Alkaline phosphatase (orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1) in guinea pig thymus was extracted optimally in 10 mM Tris - HCl buffer at pH 8.0 containing 5 g/l Triton X-100. 2. alpha-Glycerophosphate, beta-glycerophosphate and phenolphthalein monophosphate were hydrolyzed by thymus extract with a pH optimum at 9.8-10.0, whereas p-nitrophenylphosphate and alpha-naphthylphosphate were hydrolyzed with pH optima at 10.7-10.8 and beta-naphthylphosphate at pH 11.2. P-Nitrophenylphosphate and phenolphthalein monophosphate proved to be the most suitable substrates. 3. Alkaline phosphatase was effectively inhibited by EDTA, Zn2+, histidine and urea therefore resembling the inhibition characteristics of alkaline phosphatase in the placenta and kidney, but not that in the liver and intestine, which differed markedly. 4. DEAE-cellulose chromatography and polyacrylamide disc electrophoresis revealed three enzyme peaks which did not differ in their substrate specificities and modifier characteristics. 5. Polyacrylamide disc electrophoresis of thymus, serum, placenta, kidney, liver, bone and intestine revealed no alkaline phosphatase bands definitely unique to thymus.
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PMID:Biochemical characterization of alkaline phosphatase in guinea pig thymus. 1 86

The pH dependence of the human prostatic acid phosphatase-catalyzed hydrolysis of p-nitrophenyl phosphate and beta-glyceryl phosphate has been studied over a wide range of pH and the values of Km and V calculated with the aid of the Cleland HYPER program. The pH dependence of Km shows the effect of substrate ionization: pK values of 5.6 and 6.4 are observed as for the respective values of free substrates. The pH dependence of both Km and V for each substrate reveals the involvement of an ionizable group in the ES complex which is ascribed to a phosphohistidine-enzyme intermediate. The small deuterium solvent isotope effects which are observed on V are consistent with values observed for solvolysis of phosphoramidates. The measured data for Km indicates limits on burst-titration experiments of prostatic acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2).
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PMID:pH dependence and solvent isotope effects in the hydrolysis of phosphomonoesters by human prostatic acid phosphatase. 2 Sep 64

Free-flow electrophoresis was used to subfractionate membrane vesicles from calf thymocyte plasma membranes. The fractionation resulted in a separation of vesicle populations bearing four different enzymes: alkaline nitrophenyl-phosphatase (orthophosphoric-monoester phosphohydrolase (alkalin optimum) EC 3.1.3.1), gamma-glutamyltransferase (EC 2.3.2.2), (Mg2+ + Na+ + K+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) and acyl-CoA:lysophosphatidylcholine acyltransferase (acyl-CoA:1-acylglycero-3-phosphocholine-O-acyltransferase, EC 2.3.1.23). The specific content of cholesterol and total phospholipid coincided with the distribution of membrane-bound protein. However, vesicles migrating towards the cathode had a higher molar ratio of cholesterol to phospholipid (0.75) compared to those migrating to the anode (0.55). Sodium dodecyl sulphate-gel electrophoresis of pooled vesicle fractions also demonstrates distinct differences in their protein pattern. Electron-micrographic thin sections show that the vesicle populations have a similar morphology and size distribution. These results are discussed in terms of heterogeneity of the original thymocytes, contamination with intracellular membranes and a heterogeneous structure of the plasma membrane.
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PMID:Fractionation of membrane vesicles. II. A method for separation of membrane vesicles bearing different enzymes by free-flow electrophoresis. 2 91

A method is described for the localization and characterization of phospholipases A1 and A2 (EC3.1.1.4) in Krebs II ascites cells, particularly in the plasma membranes. Cells were lysed with a Dounce homogenizer in an isotonic sucrose medium. Plasma membranes sediment with mitochondria and lysosomes during subcellular fractionation and are finally isolated on a continuous sucrose gradient. The membranes are localized at two levels in the gradient, at densities of 1.06 and 1.15, in which 5'-nucleotidase (EC 3.1.3.5) activity exhibits a 9- and 21-fold purification, respectively. Total contamination by endoplasmic reticulum, lysosomes, and mitochondria is 17 percent for the low-density membrane fraction and 25 percent for the high-density fraction. The phospholipases A present in Krebs II cells are active at pH 4.0 and pH 7.5. At the 2 pH values, they have A1 and A2 specificities. The intracellular distribution of acidic forms is comparable to that of acid phosphatase (EC 3.1.3.1), while neutral forms are localized like lactate dehydrogenase (EC 1.1.1.27). A small proportion of neutral phospholipase A2 has the same repartition on the sucrose gradient as nicotinamide adenine dinucleotide diaphorase (EF 1.6.4.3), an endoplasmic reticulum marker, and as 5'-nucleotidase, a plasma membrane marker.
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PMID:Phospholipases A1 and A2 in subcellular fractions and plasma membranes of Krebs II ascites cells. 2 44

1. The kinetics of the hydrolysis of nitrophenylphosphate by nonspecific acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2.) from Schizosaccharomices pombe was studied. 2. The kinetic parameters, Km and V, were determined as well as the inhibition constants, K1, for the inhibitors, phosphate and fluoride, as a function of pH. 3. The results, interpreted according to the theories of Dixon and Waley indicated the presence of three ionizable groups on the enzyme itself and one on the enzyme-substrate complex. 4. A model of the hydrolysis of phosphoric acid monoesters by the S. pombe acid phosphatase is proposed based on the ionization state of the reactants and on the results of the inhibition by the competitive inhibitors.
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PMID:Some kinetic aspects of the mechanism of hydrolysis of phosphoric acid esters by nonspecific acid phosphatase from Schizosaccharomyces pombe. 2 60

Vicia faba root cells contain several nucleolytic activities: phosphomonoesterase and phosphodiesterase (which however were not studied in details), one nuclease and four ribonucleases. These results were obtained by separating the extracted proteins into anionic and cationic species by chromatography on CM-cellulose at pH 5.5 and analysing each kind of proteins. Anionic species were subjected to chromatography on DEAE-cellulose which lead to isolation of one nuclease (A1) and two RNAases (A2, A3), the properties of which were studied. It was shown that the RNAases pH optima are near 6; A2 is more thermolabile than A3; both are endonucleases unable to attack double-stranded structure; studies with homopolymers, i.e. poly(A), poly(I), poly(C), poly(U), showed that their base specificities were analogous to that of already known plant RNAases. The cationic proteins, analysed with CM-cellulose, contain two RNAases (C1, C2). The pH optima were near 6 and 7, respectively; C1 is much more thermolabile than C2; both were endonucleases inactive on double-stranded structures. C1 and C2 hydrolysed poly(C) and poly(U) but not poly(A) and poly(U).
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PMID:Study on plant RNAases. Isolation and properties of several activities from Vicia faba root cells. 2 32

The changes in the weight, histology and biochemical composition of the epididymis (caput, corpus and cauda segments) in prepuberal rabbit and rhesus monkey in response to testosterone treatment were investigated. The increase in the weight of the organ was accompanied by increased levels of RNA and DNA. Androgen therapy caused an increase in the concentration of sialic acid, phospholipids and glycerylphosphorylcholine and activities of alkaline phosphatase, acid phosphatase and hyaluronidase. The cauda region of the epididymis exhibited relatively higher levels of sialic acid and glycerylphosphorylcholine. These findings are discussed in relation to the functional maturation of the organ and the role of androgen in this process.
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PMID:Functional maturation of the epididymis in rabbit and rhesus monkey. 2 35

Isopycnic sedimentation has been used to separate granulocytes of varying stages of maturity from the bone marrows of normal rabbits and rabbits stimulated to undergo an intense inflammatory response. The separated cell populations were in turn utilized to study the specific activities of six intracellular enzymes. The study revealed an increase with cell maturation in the specific activities of myeloperoxidase, NADPH oxidase, alkaline phosphatase and acid phosphatase in normal animals; in stimulated animals only myeloperoxidase and NADPH oxidase increased significantly with cell maturation. Glucose-6-phosphate dehydrogenase showed no change in specific activity in all animals studied. Malate dehydrogenase tended to show a specific activity decrease in the maturing cells of normal but not in those of stimulated animals.
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PMID:Characterization of marrow granulocyte development: enzyme-specific activity profiles in response to inflammatory reactions. 2 66


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