Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphatidylinositol-specific phospholipase C of Bacillus thuringiensis caused the release of alkaline phosphatase from KB III cells and plasma membrane preparations prepared from the cells. Phosphatidylinositol-specific phospholipase C added to the culture of KB III cells inhibited cell growth by 30%. The release of alkaline phosphatase induced by phospholipase C was dependent on, or proportional to, the reaction time and the concentrations of the phospholipase C, KB III cells and plasma membrane preparation. The Arrhenius plot for phosphatase-release reaction showed a single break at 18.1 degrees C for KB III cells or at 27.3 degrees C for the plasma membrane preparation. The activation energies of the phosphatase-release reaction were 3.2 and 29.2 kcal/mol for KB III cells, and 4.3 and 26.5 kcal/mol for the plasma membrane preparation. The released alkaline phosphatase had a mol. wt of 105,000 and isoelectric points of 4.05 (major) and 4.4 (minor).
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PMID:Physiological actions of phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis on KB III cells: alkaline phosphatase release and growth inhibition. 399 97

Alkaline phosphatase was solubilized from plasma membrane of rat liver with butanol-ol, bile acids or sodium deoxycholate, and electrophoretically compared with a soluble form in serum which was derived from the liver. The three enzyme preparations from the plasma membrane migrated at the same position on polyacrylamide-gel electrophoresis in the presence of either Triton X-100 or sodium dodecyl sulphate. The mobility of them, however, was distinctly different from that of the serum-soluble form of the liver-derived alkaline phosphatase. On the other hand, phosphatidylinositol-specific phospholipase C isolated from Bacillus cereus was used to release alkaline phosphatase from plasma membrane. The released alkaline phosphatase was demonstrated to have the same mobility as the serum-soluble form on polyacrylamide-gel electrophoresis in the presence or absence of detergents. The phospholipase C also converted the butan-1-ol-extracted membrane form into the serum-soluble form. The results suggest that release of alkaline phosphatase from the liver into serum is not simply caused by a detergent effect of bile salts, but involves an enzymic hydrolysis of phosphatidylinositol, with which alkaline phosphatase may strongly interact in the membrane.
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PMID:Electrophoretic characterization of hepatic alkaline phosphatase released by phosphatidylinositol-specific phospholipase C. A comparison with liver membrane and serum-soluble forms. 399 80

Phosphatidylglycerol (PG) was extracted from 54 human amniotic fluids for the assessment of fetal lung maturity. The PG values were derived from an enzymatic assay involving initial conversion of PG to glycerol by phospholipase C and alkaline phosphatase with subsequent analysis of the glycerol formed. This method proved to be reliable when compared with a method for two-dimensional thin layer chromatographic (2D TLC) analysis of amniotic fluid phospholipids. The results revealed that in all but one of 27 amniotic fluids in which no PG was detected by 2D TLC, enzymatic PG concentrations were less than or equal to 1.5 mumol/l and out of these, from 10 newborn infants delivered within 72 h of sampling, 4 developed respiratory distress syndrome (RDS). Conversely, in all but one of 27 amniotic fluids found to contain PG by 2D TLC, enzymatic PG concentrations were greater than 1.5 mumol/l and except for one subject from non-identical twins, no infants developed RDS.
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PMID:Quantitative determination of phosphatidylglycerol in amniotic fluid by enzymatic assay. 405 5

The COOH terminus of the externally disposed variant surface glycoprotein (VSG) of the eukaryotic pathogenic protozoan Trypanosoma brucei strain 427 variant MITat 1.4 (117) is covalently linked to a novel phosphatidylinositol-containing glycolipid. This conclusion is supported by analysis of the products of nitrous acid deamination or Staphylococcus aureus phosphatidylinositol-specific phospholipase C treatment of purified membrane-form VSG. Lysis of trypanosomes is accompanied by release of soluble VSG, catalyzed by activation of an endogenous phospholipase C. The only apparent difference between membrane-form VSG and soluble VSG is the removal of sn-1,2-dimyristylglycerol. The COOH-terminal glycopeptide derived by Pronase digestion of soluble VSG was characterized by chemical modification and digestion with alkaline phosphatase. The results are consistent with the single non-N-acetylated glucosamine residue being the reducing terminus of the oligosaccharide and in a glycosidic linkage to a myo-inositol monophosphate that is probably myo-inositol 1,2-cyclic monophosphate. A partial structure for the VSG COOH-terminal moiety is presented. This structure represents a new type of eukaryotic post-translational protein modification and membrane anchor. We discuss the relevance of this structure to observations that have been made with other eukaryotic membrane proteins.
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PMID:Glycosyl-sn-1,2-dimyristylphosphatidylinositol is covalently linked to Trypanosoma brucei variant surface glycoprotein. 405 88

A lecithin sol dispersed with deoxycholate was found to be attacked by phospholipase C in the presence of calcium ion more rapidly than were any other lecithin sols. The inorganic phosphate could be released quantitatively from the acid soluble phosphate liberated from lecithin by an excess amount of alkaline phosphatase present in phospholipase C reaction mixture. A simple and accurate assay method for phospholipase C was developed with the sol and the alkaline phosphatase.
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PMID:Improved assay method for phospholipase C. 496 85

Group H streptococci (strain Challis) which are competent for transformation release a bacteriocin into liquid medium which is bacteriocidal for another group H streptococcus (strain Wicky). The streptocin (STH(1)) is resistant to treatment with deoxyribonuclease and ribonuclease but is sensitive to trypsin, phospholipase C, and alkaline phosphatase. Such enzyme sensitivity experiments indicate that the bacteriocin may be a complex molecule (protein and lipid) containing phosphate groups essential for activity. STH(1), which is readily distinguishable from competence factor and bacteriophage activity, appears to have no role in the initiation of the competent state in strain Wicky. The presence of this factor in Challis culture supernatant fluids indicates that a reevaluation of earlier studies performed with the Challis-Wicky transformation system may be necessary.
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PMID:Bacteriocin production by transformable group H streptococci. 508 61

The release of plasma-membrane-bound enzymes by phosphatidylinositol-specific phospholipase C obtained from Bacillus thuringiensis was investigated. Among the ectoenzymes of plasma membrane tested, alkaline phosphodiesterase I was released markedly from rat kidney cortex slices, in addition to alkaline phosphatase and 5'-nucleotidase. Other membrane-bound enzymes; alanine aminopeptidase, leucine aminopeptidase, dipeptidyl peptidase, leucine aminopeptidase, dipeptidyl peptidase IV, esterase and gamma-glutamyl transpeptidase could not be liberated from the treated slices. Alkaline phosphodiesterase I was released linearly from rat kidney slices with the concentration of phosphatidylinositol-specific phospholipase C, but little enzyme was released from rat liver slices. Alkaline phosphodiesterase I separated from kidney tissue with n-butanol still retained phosphatidylinositol and was transformed into a lower molecular weight form by phosphatidylinositol-specific phospholipase C. This suggests an important function for phosphatidylinositol in the binding of alkaline phosphodiesterase I to the plasma membrane of rat kidney cells. The alkaline phosphodiesterase I released from rat kidney had a molecular weight of about 240,000 and an isoelectric point (pI) of 5.4. The enzyme hydrolyzed the phosphodiester linkage of p-nitrophenyl-thymidine 5'-monophosphate at pH 8.9 and had a Km value of 0.3 mM. The enzyme was activated by Mg2+ and Ca2+, but was inhibited by EDTA. Strong inhibition took place on the addition of adenosine 5'-phosphosulfate or the nucleotide pyrophosphates, i.e., UDP-galactose and alpha, beta-methylene ATP.
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PMID:Release of alkaline phosphodiesterase I from rat kidney plasma membrane produced by the phosphatidylinositol-specific phospholipase C of Bacillus thuringiensis. 609 28

When isolated hepatocytes are incubated with phosphatidylinositol-specific phospholipase C, three cell-surface enzymes show markedly different behaviour. Most of the alkaline phosphatase is released at very low values of phosphatidylinositol hydrolysis, whereas further phosphatidylinositol hydrolysis releases only a maximum of about one-third of the 5'-nucleotidase. Alkaline phosphodiesterase I is not released. If cells containing phosphatidyl[3H]inositol are similarly treated, then the released [3H]inositol is in the form of inositol phosphate: no evidence has been obtained for any covalent association between released [3H]inositol and alkaline phosphatase.
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PMID:Selective release of plasma-membrane enzymes from rat hepatocytes by a phosphatidylinositol-specific phospholipase C. 625 May 35

A new major outer membrane protein, P, was induced in Pseudomonas aeruginosa PAO1 upon growth in medium containing 0.2 mM or less inorganic phosphate. Studies with media containing different levels of phosphate and with mutants of PAO1 suggested that protein P was coregulated with alkaline phosphatase and phospholipase C. Protein P was substantially purified and shown to form sodium dodecyl sulfate-resistant oligomers on polyacrylamide gels. The incorporation of purified protein P into artificial lipid bilayers resulted in an increase of the membrane conductance by many orders of magnitude. Single-channel experiments demonstrated that protein P channels were substantially smaller than all previously studied porins from P. aeruginosa and enteric bacteria, with an average single-channel conductance in 1 M NaCl of 0.25 nS. The protein P channel was apparently not voltage induced or regulated. The results of single-channel conductance experiments, using a variety of different salts, allowed a minimum channel diameter estimate of 0.7 nm. Furthermore, from these results it was concluded that the protein P channel was highly specific for anions. Zero-current potential measurements confirmed that protein P was at least 30-fold more permeable for Cl- than for K+ ions. The possible biological role of the small, anion-specific protein P channels in phosphate uptake from the medium is discussed.
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PMID:Outer membrane protein P of Pseudomonas aeruginosa: regulation by phosphate deficiency and formation of small anion-specific channels in lipid bilayer membranes. 627 69

We describe a method for the direct enzymatic determination of phosphatidylcholine and sphingomyelin in serum. Phospholipase C (EC 3.1.4.3) and sphingomyelinase (EC 3.1.4.12) are used to hydrolyze phosphatidylcholine and sphingomyelin, respectively, with high specificity; alkaline phosphatase (EC 3.1.3.1) is used to cleave inorganic phosphorus. The choline group, after oxidation with choline oxidase (EC 1.1.3.17), is detected with 4-aminoantipyrine. Alternatively, phosphorus is assayed with metavanadate. The excellent agreement between results of this modification of a procedure described by Artiss et al. (Microchem. J. 26: 1017, 1980) for amniotic fluid and of the conventional thin-layer chromatographic method makes this an attractive method for determination of both phospholipid subclasses in serum.
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PMID:Enzymic assay for phosphatidylcholine and sphingomyelin in serum. 634 Aug 53


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