Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.5 (neuropathy target esterase)
 1,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phospholipid peroxidation and the activities of phospholipase A, acyl Coenzyme A:lysophospholipid acyltransferase and lysophospholipase were measured in isolated bovine rod outer segments (ROS) that were incubated in the presence or absence of the added antioxidants, vitamin E and dithiothreitol (DTT), and additionally in light or dark. DTT and vitamin E significantly inhibit both lipid peroxidation and the enzyme activities. These results suggest that one function of the enzymes for molecular replacement of fatty acids in ROS, is removal of peroxidized fatty acids and thus protection of the membrane phospholipids and proteins from further oxidative damage.
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PMID:Effects of the antioxidants dithiothreitol and vitamin E on phospholipid metabolism in isolated rod outer segments. 206 29

Incubation of bovine rod outer segments (ROS) with radiolabeled palmitic acid (16:0) and lysophosphatidylcholines (lysoPC) radiolabeled in either the fatty acid or the choline group indicated the presence of a lysophospholipase activity that is unaffected by Ca2+. In the presence of ATP, Mg2+ and CoA and acyl CoA:lysophospholipid acytransferase activity is evident, and free fatty acids, including those released by lysophospholipase activity, are esterified to membrane phospholipids. At low concentrations of lysoPC, 68% of it is acylated to form phosphatidylcholine (PC) and 24% is converted to glycerophosphocholine (GPC) and fatty acid per hour. As the concentration of lysoPC increases lysophospholipase activity increases, acyl-CoA:lysophospholipid acyltransferase activity decreases, and the proportion of lysoPC converted to PC decreases. The rate of production of lysophospholipids in vitro under phospholipase A-stimulatory conditions exceeds the rate at which it can be removed by 5-10-fold. This suggests the possibility that an early step in light, anoxia- or hypoxia-induced damage to photoreceptor cells may be activation of the phospholipase A endogenous to ROS.
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PMID:Lysophospholipase and the metabolism of lysophosphatidylcholine in isolated bovine rod outer segments. 292 Jul 84

We have reported previously that a number of metabolites and toxins which cause Ca2+ release from mitochondria do so by increasing the permeability of the inner membrane. The metabolic basis of this permeability change is proposed to be perturbation of a phospholipid deacylation-reacylation cycle which results in an accumulation of free fatty acids and lysophospholipids (see Broekemeier, K. M., Schmid, P. C., Schmid, H. H. O., and Pfeiffer, D. R. (1985) J. Biol. Chem. 260, 105-113 and references therein). This hypothesis predicts that inhibitors of acyl-CoA:lysophospholipid acyltransferase would be among those agents which increase membrane permeability and that their effects on permeability could occur in the absence of pyridine nucleotide oxidation or of an accumulation of glutathione disulfide. The hypolipidemic drugs WY-14643 and clofibric acid inhibit the mitochondrial acyl-CoA:lysophospholipid acyltransferase and have the predicted effects on mitochondrial permeability properties. The development of increased permeability due to WY-14643 and clofibric acid requires accumulated Ca2+ specifically, is sensitive to inhibitors of phospholipase A2, and results in a pattern of solute release and swelling which is typical of other Ca2+-releasing agents. Neither agent promotes pyridine nucleotide nor sulfhydryl glutathione oxidation in the absence of Ca2+. In addition, the swelling response to hypolipidemic drugs is not significantly inhibited by dithiothreitol. In the presence of Ca2+, both agents promote an accumulation of free fatty acids. The composition of these lipid degradation products suggests that mitochondria treated with hypolipidemic drugs retain an active lysophospholipase whereas this enzyme is inactivated by Ca2+-releasing agents which alter mitochondrial sulfhydryl groups.
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PMID:The effect of Ca2+ and acyl coenzyme A:lysophospholipid acyltransferase inhibitors on permeability properties of the liver mitochondrial inner membrane. 377 20

It has been well recognized that acyl groups of phospholipids play an important role for structure and function of biomembrane. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. In this report, the sequential changes of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic rat brain were examined. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemic brain. Ischemic brain were produced by decapitation and activities of 5 enzymes were assayed in microsomal fraction. The activities of phospholipase A, PI-specific phospholipase C, lipase showed high value during early stage of ischemia for 15 or 30 min and then decreased gradually. Lysophospholipase activity was not changed for 120 min. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease from the beginning of ischemia. There are some reports that in early ischemic stage, the concent of free fatty acids increase, while that of phospholipid decrease. The present results may suggest that the changes of free fatty acid and phospholipid in ischemic brain are related to these enzymic system.
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PMID:[The activities of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain microsomal fraction]. 402 86

In this report, the sequential changes of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic dog brain were investigated. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemia. Hemispheric non-blood supply models were produced by occlusion of main intracranial trunk arteries in dogs according to Suzuki's method. The sample was spooned out and frozen immediately with liquid nitrogen at the predetermined time. The assay of phospholipase A1, A2 and lysophospholipase activities was done by our method and acylCoA: lysophospholipid acyltransferase activity was according to Corbin and Sun's method. The activities of phospholipase A1, A2 and lysophospholipase did not show significant changes within 60 minutes after arterial occlusion. However these activities showed significant high value at 120 minutes and decreased gradually after then. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease. These findings show that enzymic degradiation of acyl group of phospholipid in the brain is highest at about 120 minutes after complete ischemia. The importance of acyl groups of phospholipids for biomembrane structure and the function is well recognized. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. There have been some reports that the content of free fatty acids in the ischemic brain increases in early stage.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Activities of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain of the dog]. 665 88

Over 100 different phospholipid molecular species are known to be present in mammalian cells and tissues. Fatty acid remodeling systems for phospholipids including acyl-CoA: lysophospholipid acyltransferases, CoA-dependent and CoA-independent transacylation systems and lysophospholipase/transacylase are involved in the biosynthesis of these molecular species. Acyl-CoA:1-acyl-2-lysophospholipid acyltransferase prefers polyunsaturated fatty acyl-CoAs as acyl donors while acyl-CoA:2-acyl-1-lysophospholipid acyltransferase prefers saturated fatty acyl-CoAs. Therefore, the acyl-CoA:lysophospholipid acyltransferase system is involved in the synthesis of the phospholipid molecular species containing sn-1 saturated and sn-2 unsaturated fatty acids. The CoA-dependent transacylation system catalyzes the transfer of fatty acids esterified in phospholipids to lysophospholipids in the presence of CoA without the generation of free fatty acids. The CoA-dependent transacylation reaction in rat liver exhibits strict fatty acid specificity, i.e., three types of fatty acids (20:4, 18:2, and 18:0) are transferred. On the other hand, the CoA-independent transacylase catalyzes the transfer of C20 and C22 polyunsaturated fatty acids from diacyl phospholipids to various lysophospholipids, in particular, ether-containing lysophospholipids, in the absence of any cofactors. The CoA-independent transacylase is assumed to be involved in the accumulation of polyunsaturated fatty acids in ether-containing phospholipids and in the removal of deleterious ether-containing lysophospholipids. These acyltransferases and transacylases are involved in not only the remodeling of fatty acids but also the synthesis and degradation of some bioactive lipids and their precursors. In this review, the properties of these fatty acid remodeling systems and their possible roles in the biosynthesis of bioactive lipids are described.
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PMID:Acyltransferases and transacylases involved in fatty acid remodeling of phospholipids and metabolism of bioactive lipids in mammalian cells. 927 65

A combined lipidomics and transcriptomics analysis was performed on mouse myeloma SP2/0, Chinese hamster ovary (CHO), and human embryonic kidney (HEK) cells in order to compare widely used mammalian expression systems. Initial thin layer chromatography (TLC) analysis indicated that phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were the major lipid components in all cell lines with lower amounts of sphingomyelin (SM) in SP2/0 compared to CHO and HEK, which was subsequently confirmed and expanded upon following mass spectrometry (MS) analysis. HEK contained 4-10-fold higher amounts of lyso phosphatidylethanolamine (LPE) and 2-4-fold higher amounts of lyso phosphatidylcholine (LPC) compared to SP2/0 and CHO cell lines. C18:1 followed by C16:1 were the main contributors to the difference in both LPE and LPC levels. Alternatively, the SP2/0 cell line exhibited 30-65-fold lower amounts of SM principally in the amount of 16:0. By mapping the transcriptomics data to KEGG pathways, we found expression levels of secretory phospholipase A2 (sPLA2), lysophospholipid acyltransferase (LPEAT), lysophosphatidylcholine acyltransferase (LPCAT), and lysophospholipase (LYPLA) can contribute to the differences in LPE and LPC. Sphingomyelin synthases (SMS) and sphingomyelin phosphodiesterase (SMase) enzymes may play roles in SM differences across the three cell lines. The results of this study provide insights that will aid the understanding of the physiological and secretory differences across recombinant protein production systems.
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PMID:High-Throughput Lipidomic and Transcriptomic Analysis To Compare SP2/0, CHO, and HEK-293 Mammalian Cell Lines. 2799 64