Phospholipase activity

Anti-inflammatory corticosteroids reduce PG production in vivo but not in vitro. They induce the synthesis and/or release of two proteins macrocortin , MW 15,000, first isolated from perfused guinea pig lungs, and lipomodulin , MW 40,000, isolated from rabbit neutrophils. These have been reported to inhibit phospholipase A2 (Blackwell and Flower 1983), but definite proof is still lacking (Bonney and Humes 1984). It is not known whether similar proteins are induced within the CNS. Mepacrine, chlorpromazine, and halothane are all reported to inhibit the enzyme (Blackwell and Flower 1983). 

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Hanson, D. and De Leo, V.A. (1990). Long-wave ultraviolet light induces phospholipase activation in cultured human epidermal keratinocytes. J. Invest. Dermatol. 95, 158-163. 

FRET probes have not only been generated to measure the phospholipase activity but to study its substrate specificity as well. Several substrates of PLA2 with a variety of head groups and labeled with a BODIPY dye and a Dabcyl quencher were created by Rose et al. and tested against different PLAs in cells to determine substrate specificity and intracellular localization [137], The specificity of PLA2 isoforms towards the number of double bonds in the sn2 position was evaluated with a small series of PENN derivatives. It was demonstrated that the cytosolic type V PLA2 preferred substrates with a single double bond [138],... 

Thompson, N. T., Tateson, J. E., Randall, R. W., Spacey, G. D., Bonser, R. W., Garland, L. G. (1990). The temporal relationship between phospholipase activation, diradyl-glycerol formation and superoxide production in the human neutrophil. Biochem. J. 271, 209-13. 

Watson, F., Robinson, J. J., Edwards, S. W. (1992). Sequential phospholipase activation in the stimulation of the neutrophil NADPH oxidase. FEMS Microbiol. Immunol. 105, 239-48. 

Selected entries from Methods in Enzymology [vol, page(s)] Detergent-resistant phospholipase Ai from Escherichia coll membranes, 197, 309 phospholipase Ai activity of guinea pig pancreatic lipase, 197, 316 purification of rat kidney lysosomal phospholipase Ai, 197, 325 purification and substrate specificity of rat hepatic lipase, 197, 331 human postheparin plasma lipoprotein lipase and hepatic triglyceride lipase, 197, 339 phospholipase activity of milk lipoprotein lipase, 197, 345. 

Effects mediated through stimulation of phospholipase activity and mobilization of intracellular Ca +... 

Wuthier, R. E. The role of phospholipids in biological calcification. Distribution of phospholipase activity in calcifying epiphyseal cartilage. Clin. Orthop. Rel. Res. 90, 191 (1973)... 

Further support for the hypothesis that Ca2+ plays a central role in regulating phytoalexin accumulation is provided by experiments in which the turnover of phosphatidylinositol was measured in the plasma membrane of elicitor-treated carrot cells [17]. The carrot cells were first labelled with [3H]myo-inositol and, after the addition of elicitors, acid extracts of the cells were analyzed chromatographically for the production of inositol trisphosphate (IP3). In cells treated with elicitor, the release of radioactive IP3 increased with time and attained a maximum at 3 - 5 min after treatment. Phospholipase activity responsible for the degradation of phosphorylated phosphatidylinositol increased correspondingly. Several reports have shown that IP3 induces rapid release of Ca2+ from intracellular stores in animal cells [18, 19]. Studies on plant cells have also demonstrated that exogenous IP3 releases Ca2+ from microsomal preparations at micromolar concentrations, although only limited... 

Bernard J., Lahsaini A., and Massicotte G. (1994). Potassium-induced long-term potentiation in area CA1 of the hippocampus involves phospholipase activation. Hippocampus 4 447-453. 

A25. Aron, L, Jones, S., and Fielding, C. J., Human plasma lecithin cholesterol acyltransferase Characterization of cofactor-dependent phospholipase activity. J. Biol. Chem. 253, 7220-7226 (1978). 

Koka, R., Weimer, B. C. 2001. Influence of growth conditions on heat-stable phospholipase activity in Pseudomonas. J. Dairy Res. 68, 109-116. 

In addition to factors, hormones, and neurotransmitters, known to act through receptors that couple to G proteins, Table I also lists effector systems that are or may be affected directly by activated G. Of these effector systems, positive and negative regulation of adenylyl cyclase, activation of phospholipases, activation of cGMP-PDE in photoreceptor cells, and activation of K+ channels are well docu-... 

Jansen SM, Groener JEM, Poorthuis VJHM Lysosomal phospholipase activity is decreased in mucolipidosis II and III fibroblasts. Biochim Biophys Acta 1436 363-369,1999. 

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