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)

1. Phospholipase C [EC 3.1.4.3] found in the growth medium of Streptomyces hachijoensis was purified about sixty-fold by dialysis and column chromatography on Sephadex G-50. 2. The active fraction was separated by isoelectric focusing into two fractions, phospholipase C-I (pI 6.0) and phospholipase C-II (pI 5.6). 3. Both purified phospholipases C were homogeneous by immunodiffusion and were not differentiated as regards antigencity. 4. Phospholipase C-I had maximal activity at pH 8.0 and the optimal temperature was 50degree. Phospholipase C-I was stable at 50degrees for 30 min and was stable at neutral pH. 5. The activity of phospholipase C-I was inhibited by high concentrations of various detergents such as Triton X-100, sodium, cholate, SDS and was also inhibited by Ca2+, Ba2+, Al3+, and EDTA, but was stimulated by Mg2+, and ethyl ether. 6. The Km value of phospholipase C-I was 0.9 mM, using phosphatidylcholine as a substrate. 7. By the gel filtration procedure, the molecular weights of phospholipase C-I and -II were both determined to be 18,000. 8. Phosphatidylcholine, phosphatidylinositol, cardiolipin, sphingomyelin, and lysophosphatidylcholine were hydrolyzed by phospholipase C-I, but phosphatidylethanolamine and phosphatidylserine were hydrolyzed with difficulty under the same conditions, Phospholipase C-I also hydrolyzed phosphatidic acid.
J Biochem 1975 Sep
PMID:Studies on phospholipases from Streptomyces. III. Purification and properties of Streptomyces hachijoensis phospholipase C. 0 11

To obtain high yields of extracellular enzymes and toxins for immunological analysis, type culture collection strains of Clostridium perfringens types A to D and 28 fresh isolates of C. perfringens type A from humans were grown in fermenters under controlled conditions in a pre-reduced proteose peptone medium. The type culture collection strains all showed different characteristics with respect to growth rates and pH optima for growth. Production of phospholipase C (alpha-toxin), haemolysin and lethal activity varied considerably between the different types. Growth and extracellular protein production in fermenters with pH control and static or stirred cultures were compared. Production of all extracellular proteins measured was markedly improved by cultivation in fermenters with pH control. Strain ATCC13124 produced five times more phospholipase C than any of 28 freshly isolated strains of C. perfringens type A, grown under identical conditions. Haemolytic and lethal activities of the ATCC strain were equal or superior to the activities of any of the freshly isolated strains. There were no differences in the bacterial yields and in the production of extracellular toxins between type A strains isolated from clinical cases of gas gangrene and abdominal wounds, and those isolated from faecal samples from healthy persons.
J Gen Microbiol 1976 Sep
PMID:Production of phospholipase C (alpha-toxin), haemolysins and lethal toxins by Clostridium perfringens types A to D. 1 Mar 44

1. Guanylate cyclase of washed particles and plasma membranes showed S-shaped progress curves when titrated with either GTP or Mn2+ ions; similar results were obtained with Triton X-100-solubilized enzyme preparation from washed particles. Hill plots of these data revealed multiple metal-nucleotide and free-metal binding sites. 2. Guanylate cyclase of supernatant fractions displayed typical Michaelis-Menten properties when enzyme required excess of (free) Mn2+ (over GTP) for maximal activities; Ka (free Mn2+) was about 0.15-0.25 mM at subsaturating concentrations of GTP. 4 MnATP, MnADP, and MnGDP were found to increase the activities of both particulate and superantant enzyme, when MnGTP concentration was below saturation and free Mn2+ ion concentration was low (less than 100 muM); MnATP (50muM-1 mM) inhibited both these activities at high free Mn2+ concentration (1.5 mM) and inhibition of the particulate enzyme was greater than that of supernatant enzyme. 5. Ca2+ ions stimulated supernatant-enzyme activity; the stimulatory concentration of Ca2+ ions depended on the concentration of Mn2+ and GTP. 6. A modest stimulation of particulate guanylate cyclase by pyrophosphate (0.02-1 mM) was observed; the pyrophosphate effect appeared to be competitive with respect to GTP. At a higher concentration (2 mM), pyrophosphate produced a marked inhibition of particulate enzyme; the nature of inhibitory effect appeared complex. 7. Inorganic salts (e.g. NaCl, KCl, LiBr, NaF) produced inhibition of particulate enzyme; the degree of inhibition of Triton X-100-stimulated activity was less than that of unstimulated activity. 9. Treatment of sarcolemmal or microsomal membranes with either phospholipase C or trypsin decreased, whereas phospholipase A increased, the activity of guanylate cyclase.
Biochem J 1976 Sep 01
PMID:Properties of particulate, membrane-associated and soluble guanylate cyclase from cardiac muscle, skeletal muscle, cerebral cortex and liver. 1 Aug 91

Cyclic AMP phosphodiesterase (PDE) in membrane fraction from rat cerebral cortex was activated by Triton X-100, and treatment at alkaline pH and with phospholipase C. These results suggest that membrane PDE exists in a latent form and is influenced by microenvironmental changes within the membrane. Furthermore, the PDE, unlike soluble enzyme, is not influenced by a protein activator and Ca++.
Experientia 1978 Sep 15
PMID:Possible regulation of membrane-associated cyclic AMP phosphodiesterase in rat cerebral cortex by lipids. 3 Dec 95

Incubation of Rh positive ghosts with phospholipase A2 and C abolished the adsorption of Rh antibodies on the ghosts; incubation with phospholipase D, however, did not affect their adsorption and none of these phospholipases affected the adsorption of antibodies of the ABO system. The impairment of antigen-antibody-reaction in Rh positive ghosts treated with phospholipase corresponds to the absence of the antigen-antibody reaction with the membrane protein associated with Rh characteristics in the Schultz-Dale-Test. The chromatogram of the phospholipids extracted from those stromata treated with various phospholipases and those not treated showed different patterns. After incubation with phospholipase-A2 the lecithin and cephalin streaks were reduced and in addition lysophosphatide and fatty acid streaks were detected. In the case of phospholipase C the lecithin and cephalin streaks were further reduced while diglyceride streaks made their appearance. The phospholipid extracts from those stromata treated with phospholipase D and those not treated were identical. Phospholipase C reduced the values of lipid phosphorus more than did phospholipase A2, while phospholipase D did not reduce them at all. This study supports the results of other investigators who have postulated that the Rh antigens are located in a lipoprotein on the membrane of the human erythrocyte. The antigen-antibody-reaction seems to require a precise protein-phospholipid interaction.
Z Immunitatsforsch Exp Klin Immunol 1975 Sep
PMID:[The importance of phosphatidylcholine in the binding of anti-D to human erythrocyte ghost membrane (author's transl)]. 12 77

1. The action of eight purified phospholipases on intact human erythrocytes has been investigated. Four enzymes, e.g. phospholipases A2 from pancreas and Crotalus adamanteus, phospholipase C from Bacillus cereus, and phospholipase D from cabbage produce neither haemolysis nor hydrolysis of phospholipids in intact cells. On the other hand, both phospholipases A2 from bee venom and Naja naja cause a non-haemolytic breakdown of more than 50% of the lecithin, while sphingomyelinase C from Staphylococcus aureus is able to produce a non-lytic degradation of more than 80% of the sphingomyelin. 2. Phospholipase C from Clostridium welchii appeared to be the only lipolytic enzyme tested, which produces haemolysis of human erythrocytes. Evidence is presented that the unique properties of the enzyme itself, rather than possible contaminations in the purified preparation, are responsible for the observed haemolytic effect. 3. With non-sealed ghosts, all phospholipases produce essentially complete breakdown of those phospholipids which can be considered as proper substrates for the enzymes involved. 4. Due to its absolute requirement for Ca2+, pancreatic phospholipase A2 can be trapped inside resealed ghosts in the presence of EDTA, without producing phospholipid breakdown during the resealing procedure. Subsequent addition of Ca2+ stimulates phospholipase A2 activity at the inside of the resealed cell, eventually leading to lysis. Before lysis occurs, however, 25% of the lecithin, half of the phosphatidylethanolamine and some 65% of the phosphatidylserine can be hydrolysed. This observation is explained in relation to an asymmetric phospholipid distribution in red cell membranes.
Biochim Biophys Acta 1975 Sep 16
PMID:Organization of phospholipids in human red cell membranes as detected by the action of various purified phospholipases. 16 15

The haemagglutinating ability of three strains of IBV was investigated. It was shown that whereas strain Beaudette had no detectable haemagglutinin, both Connecticut and Massachusetts agglutinated red cells of various species. The haemagglutinin of Connecticut was detectable after sucrose gradient purification whereas that of Massachusetts required both the purification step and incubation with the enzyme phospholipase C to reveal it. The agglutination could be inhibited by specific antisera. Some studies on the nature of the red cell receptor, and the possible presence of a receptor destroying enzyme, are reported.
J Gen Virol 1975 Sep
PMID:Haemagglutination by avian infectious bronchitis virus-a coronavirus. 17 Mar 78

Semliki Forest virus inhibits phosphatidylethanolamine biosynthesis in baby hamster kidney-21 cells 6 h after infection. Viral infection reduced the incorporation of [1,2-14C]-ethanolamine into intact cells by approximately 50%. A similar reduction in the activity of the ethanolaminephosphotransferase (EC 2.7.8.1) was also observed. The apparent Km for CDPethanolamine was 60 muM for the microsomal enzymes from infected or mock-infected cells. In addition, exogenous diglyceride only stimulated by 1.5-fold the ethanolaminephosphotransferase from virus- or mock-infected cells, whereas the same diglyceride preparations stimulated the cholinephosphotransferase (EC 2.7.8.2) from baby hamster kidney cells by sixfold. Generation of endogenous diglyceride by pretreatment of the microsomes with phospholipase C (EC 3.1.4.3) stimulated the activity of the cholinephosphotransferase but not the ethanolaminephosphotranferase. Semliki Forest virus does not inhibit all microsomal enzymes, since the activities of NADH- K3Fe(CN)6 reductase and NADH dehydrogenase (EC 1.6.99.3) were not affected. The ethanolaminephosphotransferase from virus- and mock-infected cells showed similar profiles of activity as a function of temperature; this result and other studies suggest that that membranous environment of the ethanolaminephosphotransferase was not significantly modified by the virus.
Can J Biochem 1975 Sep
PMID:Inhibition of phosphatidylethanolamine biosynthesis in baby hamster kidney-21 cells infected with Semliki Forest virus. 17 Oct 43

Quinine activates the hydrolysis of phosphatidyl choline suspensions by phospholipase C (E.C. 3.1.4.3) obtained from Clostridium welchii. Low levels of calcium are an absolute requirement for this activation: Mg2+, Ba2+, Sr2+, and Zn2+ are ineffective. The induction period, or lag phase for this enzyme is dependent upon both calcium concentration and substrate interfacial surface area. At low concentrations (less then 50 muM) calcium ions affect the induction period but not the maximal rate of hydrolysis, whereas guinine predominantly affects the rate of hydrolysis by alterations in the surface charge carried by the substrate.
Chem Phys Lipids 1975 Sep
PMID:The activation of phospholipase C from Clostridium Welchii by quinine: an absolute requirement for calcium ions. 17 Oct 93

In the presence of CMP, cholinephosphotransferase of mouse lung microsomes catalyzes the conversion of endogenous phosphatidylcholines into 1,2-diacyl-sn-glycerols and CDPcholine. 2. In this conversion cholinephosphotransferase shows a distinct preference for those molecular species of phosphatidylcholine which contain an unsaturated fatty acid. The enzyme hardly utilizes endogenous depalmitoylglycerophosphocholine as a substrate. 3. Membrane-bound 1,2-diacyl-sn-glycerols were also prepared by treatment of mouse lung microsomes with a pure phospholipase C from Bacillus cereus. These 1,2-diacyl-sn-glycerols were subsequently utilized as substrate by cholinephosphotransferase in the formation of phosphatidylcholine. In the latter reaction, cholinephosphotransferase exhibited a pronounced preference for unsaturated 1,2-diacyl-sn-glycerols and hardly utilized the endogenous 1,2-depalmitoyl-sn-glycerol. 4. The low affinity of cholinephosphotransferase for either dipalmitoylglycerophosphocholine or 1,2-dip
Biochim Biophys Acta 1976 Sep 27
PMID:Selective utilization of endogenous unsaturated phosphatidylcholines and diacylglycerols by cholinephosphotransferase of mouse lung microsomes. 18 25


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