Publications

• Lysophospholipase--transacylase from rat lung.

  van den Bosch H., Vianen G.M., van Heusden G.P.

  Methods Enzymol 71 Pt C:513-521(1981) [PubMed] [EuropePMC]

• Purification, characterization, and inhibition by phosphatidic acid of lysophospholipase transacylase from rat liver.

  Sugimoto H., Yamashita S.

  Lysophospholipase transacylase was purified 214,360-fold to homogeneity from the rat liver 100,000 x g supernatant. After DEAE chromatography, total activity increased 12.9-fold, due to the removal of endogenous inhibitors. The inhibitors were isolated and identified as phosphatidic acid and fatty ... >> More

  Lysophospholipase transacylase was purified 214,360-fold to homogeneity from the rat liver 100,000 x g supernatant. After DEAE chromatography, total activity increased 12.9-fold, due to the removal of endogenous inhibitors. The inhibitors were isolated and identified as phosphatidic acid and fatty acid. The final preparation showed a single band on SDS-polyacrylamide electrophoresis with an M(r) of 60,000. Gel filtration through Sephacryl S-200 gave a similar value, suggesting that the enzyme exists as a monomer. Activity was highest at pH 6.0 and was not affected by Ca2+, Mg2+, and EDTA. The enzyme produced glycerophosphocholine (GPC), palmitic acid, and dipalmitoyl-GPC on incubation with 1-palmitoyl-GPC, indicating that the enzyme catalyzed both deacylation and transacylation. The relative rates of deacylation and transacylation were 1:0.3 under standard assay conditions. Km for 1-palmitoyl-GPC and Vmax of hydrolase activity were 91 microM and 12.9 mumol/min/mg, respectively. The enzyme was selective for choline lysophospholipid. Ethanolamine, inositol, and serine lysophospholipids were not good substrates of the enzyme. Phosphatidic acid was a potent, competitive inhibitor of the enzyme with Ki of about 10 microM as determined with 1-stearoyl-2-arachidonoyl glycerophosphate. Although less potent, lysophosphatidic acid, palmitoyl-L-carnitine, and fatty acid were also inhibitory to the enzyme. << Less

  J. Biol. Chem. 269:6252-6258(1994) [PubMed] [EuropePMC]

  This publication is cited by 8 other entries.

• Loss of neuropathy target esterase in mice links organophosphate exposure to hyperactivity.

  Winrow C.J., Hemming M.L., Allen D.M., Quistad G.B., Casida J.E., Barlow C.

  Neuropathy target esterase (NTE) is involved in neural development and is the target for neurodegeneration induced by selected organophosphorus pesticides and chemical warfare agents. We generated mice with disruptions in Nte, the gene encoding NTE. Nte(-/-) mice die after embryonic day 8, and Nte ... >> More

  Neuropathy target esterase (NTE) is involved in neural development and is the target for neurodegeneration induced by selected organophosphorus pesticides and chemical warfare agents. We generated mice with disruptions in Nte, the gene encoding NTE. Nte(-/-) mice die after embryonic day 8, and Nte(+/-) mice have lower activity of Nte in the brain and higher mortality when exposed to the Nte-inhibiting compound ethyl octylphosphonofluoridate (EOPF) than do wild-type mice. Nte(+/-) and wild-type mice treated with 1 mg per kg of body weight of EOPF have elevated motor activity, showing that even minor reduction of Nte activity leads to hyperactivity. These studies show that genetic or chemical reduction of Nte activity results in a neurological phenotype of hyperactivity in mammals and indicate that EOPF toxicity occurs directly through inhibition of Nte without the requirement for Nte gain of function or aging. << Less

  Nat. Genet. 33:477-485(2003) [PubMed] [EuropePMC]

• Evidence that mouse brain neuropathy target esterase is a lysophospholipase.

  Quistad G.B., Barlow C., Winrow C.J., Sparks S.E., Casida J.E.

  Neuropathy target esterase (NTE) is inhibited by several organophosphorus (OP) pesticides, chemical warfare agents, lubricants, and plasticizers, leading to OP-induced delayed neuropathy in people (>30,000 cases of human paralysis) and hens (the best animal model for this demyelinating disease). T ... >> More

  Neuropathy target esterase (NTE) is inhibited by several organophosphorus (OP) pesticides, chemical warfare agents, lubricants, and plasticizers, leading to OP-induced delayed neuropathy in people (>30,000 cases of human paralysis) and hens (the best animal model for this demyelinating disease). The active site region of NTE as a recombinant protein preferentially hydrolyzes lysolecithin, suggesting that this enzyme may be a type of lysophospholipase (LysoPLA) with lysolecithin as its physiological substrate. This hypothesis is tested here in mouse brain by replacing the phenyl valerate substrate of the standard NTE assay with lysolecithin for an "NTE-LysoPLA" assay with four important findings. First, NTE-LysoPLA activity, as the NTE activity, is 41-45% lower in Nte-haploinsufficient transgenic mice than in their wild-type littermates. Second, the potency of six delayed neurotoxicants or toxicants as in vitro inhibitors varies from IC50 0.02 to 13,000 nM and is essentially the same for NTE-LysoPLA and NTE (r2 = 0.98). Third, the same six delayed toxicants administered i.p. to mice at multiple doses inhibit brain NTE-LysoPLA and NTE to the same extent (r2 = 0.90). Finally, their in vivo inhibition of brain NTE-LysoPLA generally correlates with delayed toxicity. Therefore, OP-induced delayed toxicity in mice, and possibly the hyperactivity associated with NTE deficiency, may be due to NTE-LysoPLA inhibition, leading to localized accumulation of lysolecithin, a known demyelinating agent and receptor-mediated signal transducer. This mouse model has some features in common with OP-induced delayed neuropathy in hens and people but differs in the neuropathological signs and apparently the requirement for NTE aging. << Less

  Proc Natl Acad Sci U S A 100:7983-7987(2003) [PubMed] [EuropePMC]

• Studies on lysophospholipases. I. Purification and some properties of a lysophospholipase from beef pancreas.

  van den Bosch H., Aarsman A.J., de Jong J.G., van Deenem L.L.

  Biochim Biophys Acta 296:94-104(1973) [PubMed] [EuropePMC]

• Studies on the hydrolysis of lecithin by a Penicillium notatum phospholipase B preparation.

  DAWSON R.M.

  Biochem J 70:559-570(1958) [PubMed] [EuropePMC]

• Neuropathy target esterase and a homologous Drosophila neurodegeneration-associated mutant protein contain a novel domain conserved from bacteria to man.

  Lush M.J., Li Y., Read D.J., Willis A.C., Glynn P.

  The N-terminal amino acid sequences of proteolytic fragments of neuropathy target esterase (NTE), covalently labelled on its active-site serine by a biotinylated organophosphorus ester, were determined and used to deduce the location of this serine residue and to initiate cloning of its cDNA. A pu ... >> More

  The N-terminal amino acid sequences of proteolytic fragments of neuropathy target esterase (NTE), covalently labelled on its active-site serine by a biotinylated organophosphorus ester, were determined and used to deduce the location of this serine residue and to initiate cloning of its cDNA. A putative NTE clone, isolated from a human foetal brain cDNA library, encoded a 1327 residue polypeptide with no homology to any known serine esterases or proteases. The active-site serine of NTE (Ser-966) lay in the centre of a predicted hydrophobic helix within a 200-amino-acid C-terminal domain with marked similarity to conceptual proteins in bacteria, yeast and nematodes; these proteins may comprise a novel family of potential serine hydrolases. The Swiss Cheese protein which, when mutated, leads to widespread cell death in Drosophila brain [Kretzschmar, Hasan, Sharma, Heisenberg and Benzer (1997) J. Neurosci. 17, 7425-7432], was strikingly homologous to NTE, suggesting that genetically altered NTE may be involved in human neurodegenerative disease. << Less

  Biochem. J. 332:1-4(1998) [PubMed] [EuropePMC]

• Human neuropathy target esterase catalyzes hydrolysis of membrane lipids.

  van Tienhoven M., Atkins J., Li Y., Glynn P.

  A neuronal membrane protein, neuropathy target esterase (NTE), reacts with those organophosphates that initiate a syndrome of axonal degeneration. NTE has homologues in Drosophila and yeast and is detected in vitro by assays with a non-physiological ester substrate, phenyl valerate. We report that ... >> More

  A neuronal membrane protein, neuropathy target esterase (NTE), reacts with those organophosphates that initiate a syndrome of axonal degeneration. NTE has homologues in Drosophila and yeast and is detected in vitro by assays with a non-physiological ester substrate, phenyl valerate. We report that NEST, the recombinant esterase domain of NTE (residues 727-1216) purified from bacterial lysates, can catalyze hydrolysis of several naturally occurring membrane-associated lipids. The active site regions of NEST and calcium-independent phospholipase A(2) (iPLA(2)) share sequence similarity, and the phenyl valerate hydrolase activity of NEST is inhibited by low concentrations of iPLA(2) inhibitors. However, on incubation with NEST, fatty acid was liberated only extremely slowly from the sn-2 position of phospholipids (V(max) approximately 0.01 micromol/min/mg and K(m) approximately 0.4 mm for 1-palmitoyl, 2-oleoylphosphatidylcholine). Comparison of the NEST-mediated generation of (14)C-labeled products from two differentially labeled (14)C-phospholipid substrates suggested that a rate-limiting sn-2 cleavage was followed very rapidly by hydrolysis of the resulting lysophospholipid. Among the various naturally occurring lipids tested with NEST, lysophospholipids were by far the most avidly hydrolyzed substrates (V(max) approximately 20 micromol/min/mg and K(m) approximately 0.05 mm for 1-palmitoyl-lysophosphatidylcholine). NEST also catalyzed the hydrolysis of monoacylglycerols, preferring the 1-acyl to the 2-acyl isomer (V(max) approximately 1 micromol/min/mg and K(m) approximately 0.4 mm for 1-palmitoylglycerol). NEST did not catalyze hydrolysis of di- or triacylglycerols or fatty acid amides. This demonstration that membrane lipids are its putative cellular substrates raises the possibility that NTE and its homologues may be involved in intracellular membrane trafficking. << Less

  J. Biol. Chem. 277:20942-20948(2002) [PubMed] [EuropePMC]

  This publication is cited by 8 other entries.

• The preparation and properties of a lysophospholipase from Penicillium notatum.

  FAIRBAIRN D.

  J Biol Chem 173:705-714(1948) [PubMed] [EuropePMC]

• The highly selective production of 2-arachidonoyl lysophosphatidylcholine catalyzed by purified calcium-independent phospholipase A2gamma: identification of a novel enzymatic mediator for the generation of a key branch point intermediate in eicosanoid signaling.

  Yan W., Jenkins C.M., Han X., Mancuso D.J., Sims H.F., Yang K., Gross R.W.

  Herein, we report the heterologous expression of the human peroxisomal 63-kDa calcium-independent phospholipase A2gamma (iPLA2gamma) isoform in Sf9 cells, purification of the N-terminal His-tagged enzyme by affinity chromatography, and the identification of its remarkable substrate selectivity tha ... >> More

  Herein, we report the heterologous expression of the human peroxisomal 63-kDa calcium-independent phospholipase A2gamma (iPLA2gamma) isoform in Sf9 cells, purification of the N-terminal His-tagged enzyme by affinity chromatography, and the identification of its remarkable substrate selectivity that results in the highly selective generation of 2-arachidonoyl lysophosphatidylcholine. Mass spectrometric analyses demonstrated that purified iPLA2gamma hydrolyzed saturated or monounsaturated aliphatic groups readily from either the sn-1 or sn-2 positions of phospholipids. In addition, purified iPLA2gamma effectively liberated arachidonic acid from the sn-2 position of plasmenylcholine substrates. In contrast, incubation of iPLA2gamma with 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine resulted in the rapid release of palmitic acid and the selective accumulation of 2-arachidonoyl lysophosphatidylcholine (LPC), which was not metabolized further by iPLA2gamma. The putative regiospecificity of the 2-arachidonoyl LPC product was authenticated by its diagnostic fragmentation pattern during tandem mass spectrometric analysis. To identify the physiological relevance of iPLA2gamma-mediated 2-arachidonoyl LPC production utilizing naturally occurring membranes, we incubated purified rat hepatic peroxisomes with iPLA2gamma and similarly identified the selective accumulation of 2-arachidonoyl LPC. Furthermore, tandem mass spectrometric analysis demonstrated that 2-arachidonoyl LPC is a natural product in human myocardium, a tissue in which iPLA2gamma expression is robust. Because 2-arachidonoyl LPC represents a key branch point intermediate that can potentially lead to a variety of bioactive molecules in eicosanoid signaling (e.g. arachidonic acid, 2-arachidonoylglycerol), these results have uncovered a novel eicosanoid selective pathway through iPLA2gamma-mediated 2-arachidonoyl LPC production to amplify and diversify the repertoire of biologic lipid second messengers in response to cellular stimulation. << Less

  J. Biol. Chem. 280:26669-26679(2005) [PubMed] [EuropePMC]

  This publication is cited by 9 other entries.

• Purification and properties of a lysolecithinase from pancreas.

  SHAPIRO B.

  Biochem J 53:663-666(1953) [PubMed] [EuropePMC]