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Miura H, Mizuguchi H, Amano-Iwashita M, Maeda-Kogure R, Negishi A, Sakai A, Toyama T, Kawai H, Mitsumoto A, Kudo N. Clofibric acid increases molecular species of phosphatidylethanolamine containing arachidonic acid for biogenesis of peroxisomal membranes in peroxisome proliferation in the liver. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158963. [PMID: 33945875 DOI: 10.1016/j.bbalip.2021.158963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/22/2021] [Accepted: 04/28/2021] [Indexed: 01/22/2023]
Abstract
The biogenesis of peroxisomes in relation to the trafficking of proteins to peroxisomes has been extensively examined. However, the supply of phospholipids, which is needed to generate peroxisomal membranes in mammals, remains unclear. Therefore, we herein investigated metabolic alterations induced by clofibric acid, a peroxisome proliferator, in the synthesis of phospholipids, particularly phosphatidylethanolamine (PE) molecular species, and their relationship with the biogenesis of peroxisomal membranes. The subcutaneous administration of clofibric acid to rats at a relatively low dose (130 mg/kg) once a day time-dependently and gradually increased the integrated perimeter of peroxisomes per 100 μm2 hepatocyte cytoplasm (PA). A strong correlation was observed between the content (μmol/mg DNA) of PE containing arachidonic acid (20:4) and PA (r2 = 0.9168). Moreover, the content of PE containing octadecenoic acid (18:1) positively correlated with PA (r2 = 0.8094). The treatment with clofibric acid markedly accelerated the formation of 16:0-20:4 PE by increasing the production of 20:4 and the activity of acyl chain remodeling of pre-existing PE molecular species. Increases in the acyl chain remodeling of PE by clofibric acid were mainly linked to the up-regulated expression of the Lpcat3 gene. On the other hand, clofibric acid markedly increased the formation of palmitic acid (16:0)-18:1 PE through de novo synthesis. These results suggest that the enhanced formation of particular PE molecular species is related to increases in the mass of peroxisomal membranes in peroxisome proliferation in the liver.
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Affiliation(s)
- Hiroaki Miura
- Research and Development Laboratories, Maruho Co., 1 Awatacho, Chudoji, Shimogyo-ku, Kyoto 600-8815, Japan
| | - Hiroki Mizuguchi
- School of Pharmacy and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Mino Amano-Iwashita
- School of Pharmacy and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Rie Maeda-Kogure
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Akio Negishi
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Ayako Sakai
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Tomoaki Toyama
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Hiroshi Kawai
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Atsushi Mitsumoto
- Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan
| | - Naomi Kudo
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan.
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Changes in the lipid composition of Bradyrhizobium cell envelope reveal a rapid response to water deficit involving lysophosphatidylethanolamine synthesis from phosphatidylethanolamine in outer membrane. Res Microbiol 2018; 169:303-312. [DOI: 10.1016/j.resmic.2018.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 04/30/2018] [Accepted: 05/25/2018] [Indexed: 11/21/2022]
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Hirose A, Yamazaki T, Sakamoto T, Sunaga K, Tsuda T, Mitsumoto A, Kudo N, Kawashima Y. Clofibric acid increases the formation of oleic acid in endoplasmic reticulum of the liver of rats. J Pharmacol Sci 2011; 116:362-72. [PMID: 21757842 DOI: 10.1254/jphs.11020fp] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The effects of 2-(4-chlorophenoxy)-2-methylpropionic acid (clofibric acid) on the formation of oleic acid (18:1) from stearic acid (18:0) and utilization of the 18:1 formed for phosphatidylcholine (PC) formation in endoplasmic reticulum in the liver of rats were studied in vivo. [¹⁴C]18:0 was intravenously injected into control Wistar male rats and rats that had been fed on a diet containing 0.5% (w/w) clofibric acid for 7 days; and the distribution of radiolabeled fatty acids among subcellular organelles, microsomes, peroxisomes, and mitochondria, was estimated on the basis of correction utilizing the yields from homogenates of marker enzymes for these organelles. The radioactivity was mostly localized in microsomes and the radiolabeled fatty acids present in microsomes were significantly increased by the treatment of rats with clofibric acid. The formation of radiolabeled 18:1 in microsomes markedly increased and incorporations of the formed [¹⁴C]18:1 into PC and phosphatidylethanolamine in microsomes were augmented in response to clofibric acid. The [¹⁴C]18:1 incorporated into PC was mostly located at the C-2 position, but not the C-1 position, of PC, and the radioactivity in 18:1 at the C-2 position of PC was strikingly increased by clofibric acid. These results obtained from the in vivo experiments directly link the findings that clofibric acid treatment induces microsomal stearoyl-CoA desaturase and 1-acylglycerophosphocholine acyltransferase in the liver and the findings that the treatment with the drug elevated absolute mass and mass proportion of 18:1 at the C-2 position, but not the C-1 position, of PC in the liver together.
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Affiliation(s)
- Akihiko Hirose
- Division of Risk Assessment, National Institute of Health Sciences, Japan
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Higgins JA, Barrnett RJ. STUDIES ON THE BIOGENESIS OF SMOOTH ENDOPLASMIC RETICULUM MEMBRANES IN LIVERS OF PHENOBARBITAL-TREATED RATS : I. The Site of Activity of Acyltransferases Involved in Synthesis of the Membrane Phospholipid. ACTA ACUST UNITED AC 2010; 55:282-98. [PMID: 19866788 PMCID: PMC2108796 DOI: 10.1083/jcb.55.2.282] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The localization of acyltransferases involved in acylation of α-glycerophosphate, during phenobarbital induced proliferation of smooth endoplasmic reticulum (ser) membranes, has been investigated using cytochemical and cell fractionation techniques. In cytochemical studies of normal rat liver, reaction product marking acyltransferase activity was associated to the greatest extent with the rough endoplasmic reticulum (rer) membranes and to a lesser extent with ser membranes. In liver from phenobarbital-treated rats, reaction product was largely restricted to ser membranes. The specific activity of the acyltransferases of rough microsomes from normal rat liver was higher than that of the smooth microsomes. On injection of phenobarbital, this fell rapidly after three injections to a low level, at which it remained during subsequent treatment. The specific activity of the smooth microsomes, on injection of phenobarbital, rose to a peak 12 hr after the first injection, after which it fell to a level at an activity above that of smooth microsomes of normal liver. A mechanism is postulated for the biogenesis of smooth membranes in which the phospholipid is synthesized in situ and the protein is synthesized in the rer and moves to the site of newly synthesized phospholipid, where it is inserted to produce a whole membrane.
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Affiliation(s)
- J A Higgins
- Department of Anatomy, Yale School of Medicine, New Haven, Connecticut 06510
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5
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Fuller N, Rand RP. The influence of lysolipids on the spontaneous curvature and bending elasticity of phospholipid membranes. Biophys J 2001; 81:243-54. [PMID: 11423410 PMCID: PMC1301507 DOI: 10.1016/s0006-3495(01)75695-0] [Citation(s) in RCA: 246] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The effects of lysolipids on phospholipid layer curvature and bending elasticity were examined using x-ray diffraction and the osmotic stress method. Lysolipids with two different head groups, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), and differing hydrocarbon chains were mixed with the hexagonal-forming lipid, dioleoylphosphatidylethanolamine (DOPE). With up to 30 mole% lysolipid in DOPE, the mixture maintains the inverted hexagonal (H(II)) phase in excess water, where increasing levels of lysolipid result in a systematic increase in the H(II) lattice dimension. Analysis of the structural changes imposed by lysolipids show that, opposite to DOPE itself, which has an spontaneous radius of curvature (R(0)) of -30 A, PC lysolipids add high positive curvature, with R(0) = +38 to +60 A, depending on chain length. LysoPEs, in contrast, add very small curvatures. When both polar group and hydrocarbon chains of the added lysolipid mismatch those of DOPE, the structural effects are qualitatively different from otherwise. Such mismatched lysolipids "reshape" the effective combination molecule into a longer and more cylindrical configuration compared to those lysolipids with either matching polar group or hydrocarbon chain.
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Affiliation(s)
- N Fuller
- Department of Biological Sciences, Brock University, St.Catharines, Ontario L2S 3A1, Canada.
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Jaeger H, Wilcox HG, Bitterle T, Mössner J, Berr F. Intracellular supply of phospholipids for biliary secretion: evidence for a nonvesicular transport component. Biochem Biophys Res Commun 2000; 268:790-7. [PMID: 10679284 DOI: 10.1006/bbrc.2000.2220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholipids (PL) for biliary secretion could be supplied from the endoplasmic reticulum (ER) to the plasma membrane by cytosolic transfer proteins or transport vesicles. Therefore, we studied whether biliary secretions of PL and apolipoprotein A-I (apo A-I), as markers for the ER-to-Golgi vesicular transport pathway, are tightly coupled in isolated perfused rat livers with enhanced secretion (+60%) of PL after withdrawal of the cholesterol synthesis inhibitor pravastatin (0.1% of chow, fed for 7 days). Blocking agents dissociated the secretion of apo A-I and PL. Brefeldin A as well as cycloheximide inhibited biliary secretion of apo A-I (-52%; -68%), however, not of PL. Both bilirubin ditaurate and taurodehydrocholic acid reduced biliary secretion of PL (-27%; -79%), but not of apo A-I. The data support the concept that PL destined for biliary secretion bypass the vesicular transport pathway of apo A-I through the Golgi compartment, most likely via cytosolic transfer proteins.
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Affiliation(s)
- H Jaeger
- Department of Medicine II, University of Leipzig, Leipzig, D-04103, Germany
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Affiliation(s)
- W E Lands
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
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Jackson SK. Role of lipid metabolites in the signalling and activation of macrophage cells by lipopolysaccharide. Prog Lipid Res 1997; 36:227-44. [PMID: 9640457 DOI: 10.1016/s0163-7827(97)00010-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S K Jackson
- Department of Medical Microbiology, University of Wales College of Medicine, Cardiff, U.K
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9
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Affiliation(s)
- P C Choy
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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Berr F, Jaeger HC, Bitterle T, Mössner J. Evidence for secretory coupling of phosphatidylcholine molecular species to cholesterol in rat bile. J Hepatol 1997; 26:1069-78. [PMID: 9186838 DOI: 10.1016/s0168-8278(97)80116-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND/AIMS Hepatocytes secrete cholesterol into bile within lipid vesicles of selected phosphatidylcholines, mainly palmitoyl-linoleoyl-phosphatidylcholines, palmitoleoyl-oleoyl-phosphatidylcholines and palmitoleoyl-arachidonyl-phosphatidylcholines, which could in part determine the secreted amount of cholesterol. AIMS To study whether increased secretion of cholesterol, as caused by manipulation of cholesterol synthesis rate, changes the composition of phosphatidylcholines secreted in bile. METHODS Livers from control rats (Control), rats fed pravastatin for 7 days (Pravastatin) and livers isolated 5-7 or 8-11 hours after pravastatin had been withdrawn (Rebound5-7h; Rebound8-11h) were isolated perfused during infusion of taurocholic acid (400 nmol/min/100 g rat), to study biliary secretion of bile salts, cholesterol and phosphatidylcholine molecular species. RESULTS Bile salt secretion rate was similar in all four groups, secretion of cholesterol and phosphatidylcholines was similar in Control and Pravastatin. With duration of pravastatin withdrawal the secretion rates of phosphatidylcholine and cholesterol progressively increased by +38% and +122% in Rebound5-7h and by +70% and +300% in Rebound8-11h (vs Control), respectively. In parallel, the secretion rates of palmitoleoyl-oleoyl- and palmitoleoyl-arachidonyl-phosphatidylcholines rose up to sixfold and twofold, respectively, while the secretion rate of palmitoyl-linoleoylphospatidylcholines remained constant. The secretion rate of cholesterol was correlated (p < 0.01) with the secretion rates of palmitoleoyl-oleoyl-phosphatidylcholines (r = 0.83) and palmitoleoyl-arachidonyl-phosphatidylcholines (r = 0.81). Bilirubin ditaurate or taurodehydrocholate reduced (p < 0.05) biliary secretion of phosphatidylcholines (-33%; -72%) without changes in cholesterol/phosphatidylcholine secretory ratio or phosphatidylcholine species. CONCLUSIONS The secretion of the major molecular species of phosphatidylcholine in bile could be coregulated with the amount of cholesterol destined for biliary secretion.
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Affiliation(s)
- F Berr
- Dept. of Medicine II, University of Leipzig, Germany
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11
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Fyrst H, Pham DV, Lubin BH, Kuypers FA. Formation of vesicles by the action of acyl-CoA:1-acyllsophosphatidylcholine acyltransferase from rat liver microsomes: optimal solubilization conditions and analysis of lipid composition and enzyme activity. Biochemistry 1996; 35:2644-50. [PMID: 8611569 DOI: 10.1021/bi952268m] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The enzyme acyl coenzyme A:1-acyllysophosphatidylcholine acyltransferase (acyl-CoA:lysoPC acyltransferase) can be isolated in newly formed phosphatidylcholine (PC) vesicles by solubilization of rat liver microsomes with the two substrates lysoPC and acyl-CoA. In this study, we sought to optimized the conditions for the formation of PC vesicles and analyzed the lipid composition and enzyme activity of the newly formed vesicles. Analysis of PC vesicles formed by incubation of the microsomal preparation with 1-(C16:0)lysoPC and C18:1CoA, C18:2CoA, or C20:4CoA showed that the optimal protein:lysoPC ratio was 1:5 (by weight) and the optimal lysoPC:acyl-CoA ratio was 1:1 (molar amounts). PC formation increased with incubation time; after 20 h of incubation at 37 degrees C, approximately 75% of the lysoPC was converted to PC in the incubation mixture. The phospholipid molecular species composition of the vesicles reflected almost exclusively the substrates used; the vesicles contained approximately 33% of the total acyl-CoA:lysoPC acyltransferase activity from the microsomes and demonstrated a single protein band with a molecular mass of 21 kDa by gel electrophoresis. The procedure selected for the enzyme specific for lysoPC acylation, as enzyme activity toward lysophosphatidylethanolamine (lysoPE), lysophosphatidylserine (lysoPS), and lysophosphatidylinositol (lysoPI), was very low. In addition, the utilization of different acyl-CoA substrates for acylation of lysoPC was different from that in microsomes. These results show that an enzyme specific for the formation of PC from lysoPC can be isolated in PC vesicles with a designed phospholipid molecular species composition and that the lipid environment plays an important role in the regulation of the enzyme's affinity for its substrates.
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Affiliation(s)
- H Fyrst
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
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12
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Chilton FH, Fonteh AN, Surette ME, Triggiani M, Winkler JD. Control of arachidonate levels within inflammatory cells. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1299:1-15. [PMID: 8555241 DOI: 10.1016/0005-2760(95)00169-7] [Citation(s) in RCA: 182] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- F H Chilton
- Department of Internal Medicine, Bowman Gray School of Medicine, Winston-Salem, NC 27157, USA
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13
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Wilson HM, Neumuller W, Eibl H, Welch W, Reitz RC. Structural basis of the phospholipid acyltransferase enzyme substrate specificity: a computer modeling study of the phospholipid acceptor molecule. J Lipid Res 1995. [DOI: 10.1016/s0022-2275(20)39877-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Mori H, Ishiguro K, Okuyama H. Hypertension in rats does not potentiate hypercholesterolemia and aortic cholesterol deposition induced by a hypercholesterolemic diet. Lipids 1993; 28:109-13. [PMID: 8441335 DOI: 10.1007/bf02535773] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of a hypercholesterolemic diet (HCD) on hyperlipemia and atherogenesis was investigated using normotensive Wistar/Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP), with systolic blood pressures increasing in that order. Feeding an HCD diet containing cholesterol, cholate and suet induced hypercholesterolemia in all the strains examined as compared with a normal diet. The plasma cholesterol levels were significantly higher in WKY than in SHR and SHRSP fed the HCD diet. The HCD diet also induced hepatic fat deposition, particularly deposition of cholesteryl esters, a slight increase in aortic cholesterol deposition, and elevation of both monoenoic/saturated fatty acid ratios and linoleate/arachidonate ratios in tissue lipids. The changes induced in the three strains by the HCD diet were not positively correlated with blood pressures. The HCD diet affected hepatic acyl-CoA:cholesterol acyltransferase and plasma lecithin:cholesterol acyltransferase activities differently in WKY and SHR which, in addition to the induction of delta 9 desaturase, may partly account for the difference in the diet-induced changes in the fatty acid compositions of plasma cholesteryl esters. The results indicate that hypertension per se does not stimulate the development of hypercholesterolemia and arterial cholesterol deposition induced by an HCD diet, suggesting that other factors are involved.
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Affiliation(s)
- H Mori
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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15
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Ueda H, Kobayashi T, Kishimoto M, Tsutsumi T, Okuyama H. EDTA-insensitive deacylation of phosphatidylinositol in porcine platelet membranes. Life Sci 1993; 53:629-34. [PMID: 8350678 DOI: 10.1016/0024-3205(93)90272-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Pathways for EDTA-insensitive degradation of phosphatidylinositol (PI) were investigated in porcine platelet membranes and cytosol. The incubation of platelet membranes with [3H]glycerol-labeled PI in the presence of 2mM EDTA produced [3H]lysoPI and aqueous radioactive products, but not radioactive neutral lipids. The degradation in the membranes was optimal at pH8.0-9.0, while EDTA-insensitive hydrolysis was also observed in cytosol with optimal pH at pH7.0-9.0. The major water-soluble product was identified as glycerophosphoinositol. Under the conditions, [14C]arachidonate was released from 1-stearoyl-2-[14C]arachidonyl PI without accumulation of [14C]lysoPI. The deacylation activity preferred PI to phosphatidylcholine and phosphatidylethanolamine. Collectively, these results suggest that PI can be converted to lysoPI by phospholipase A2 in the absence of free Ca2+, providing the substrates for lysoPI-specific phospholipase C characterized earlier in porcine platelet membranes (Murase and Okuyama (1985) J.Biol.Chem. 260, 262-265).
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Affiliation(s)
- H Ueda
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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Mukherjee JJ, Tardi PG, Choy PC. Solubilization and modulation of acyl-CoA:1-acyl-glycerophosphocholine acyltransferase activity in rat liver microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1123:27-32. [PMID: 1730043 DOI: 10.1016/0005-2760(92)90167-t] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The acylation of 1-acyl-glycerophosphocholine is an important mechanism for the maintenance of the asymmetrical distribution of acyl groups in phosphatidylcholine. The majority of acyl-CoA:1-acyl-glycerophosphocholine acyltransferase is located in the microsomal fraction. In this study, the rat liver microsomes were incubated with various detergents, and the solubilized enzyme was separated from the remainder by centrifugation. Sodium cholate, sodium deoxycholate and octylglucopyranoside caused the solubilization of 14-25% of the enzyme activity. The acyl specificity of the solubilized enzyme was similar to the insoluble enzyme, indicating that there was no selective solubilization of any acyl specific acyltransferase. The solubilized enzyme did not display any lipid requirement, and its activity was inhibited by phosphatidylcholine, phosphatidylethanolamine and 1,2-diacylglycerol. Kinetic studies with varying concentrations of acyl-CoAs revealed that the inhibition by 1,2-diacylglycerol was essentially uncompetitive. The modulation of acyltransferase activity by 1,2-diacylglycerol may be an important mechanism for controlling the acylation of lysophosphatidylcholine.
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Affiliation(s)
- J J Mukherjee
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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Generation of the mitochondrial permeability transition does not involve inhibition of lysophospholipid acylation. Acyl-coenzyme A:1-acyllysophospholipid acyltransferase activity is not found in rat liver mitochondria. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54765-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
Interdisciplinary cooperation between basic and clinical research has resulted in the discovery and development of alkylphosphocholines, a new class of substances for the treatment of breast cancer. In contrast to most antitumor substances, the alkylphosphocholines do not attack the cell nucleus, but the cell membrane. This report presents a systematic study which, for the first time, provides a correlation between their chemical structure, antitumor efficacy and selectivity. Through an understanding of the metabolism of tumor growth inhibiting (ether)-lysolecithins, the minimal structural requirements for the antineoplastic efficacy of these substances have been obtained. This knowledge was used to identify molecular structures which are more effective and less toxic for the organism. The active principle derived from a study of (ether)-lysolecithins active as antitumor agents represents a new class of compounds: the alkylphosphocholines. As reported here, hexadecylphosphocholine is the most promising candidate of this group of compounds. It has an extremely selective action against chemically induced, autochthonous rat mammary carcinomas. No loss of activity was observed when comparing oral and intravenous administration. Particularly striking (and favorable for long-term therapy) is the fact that immunosuppression and hematotoxicity were not found at drug concentrations which lead to complete tumor remissions. Results obtained from animal experiments have been confirmed by preliminary clinical investigations.
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Affiliation(s)
- H Eibl
- Max-Planck-Institute for Biophysical Chemistry, University Hospital Göttingen, Germany
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Shimokawa T, Moriuchi A, Hori T, Saito M, Naito Y, Kabasawa H, Nagae Y, Matsubara M, Okuyama H. Effect of dietary alpha-linolenate/linoleate balance on mean survival time, incidence of stroke and blood pressure of spontaneously hypertensive rats. Life Sci 1988; 43:2067-75. [PMID: 2905408 DOI: 10.1016/0024-3205(88)90356-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Following the suckling period, stroke-prone spontaneously hypertensive rats (SHR-SP) were fed semi-purified diets supplemented either with safflower seed oil (rich in linoleic acid) or with perilla seed oil (rich in alpha-linolenic acid). The mean survival time of male SHR-SP fed the perilla diet was longer than that fed the safflower diet by 17% (p less than 0.001) while the difference was 15% in female SHR-SP (p less than 0.05). The mean survival times of female SHR-SP were more than 40% longer than those of male SHR-SP in both dietary groups. Post-mortem examinations of brains revealed apoplexy-related symptoms as the major cause of the death in both dietary groups. The systolic blood pressure was lower by ca. 10% (21 mmHg) in the perilla group than in both the safflower group and conventional diet group. The eicosapentaenoate (20:5 n-3)/arachidonate (20:4 n-6) ratio of platelet phospholipids in spontaneously hypertensive rat (SHR), a measure of platelet aggregability, was much higher in the perilla group than in the safflower group. Thus, increasing the dietary alpha-linolenate/linoleate ratio resulted in an increased mean survival time of SHR-SP rats, possibly by lowering blood pressure and platelet aggregability.
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Affiliation(s)
- T Shimokawa
- Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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22
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Kawashima Y, Bell RM. Assembly of the endoplasmic reticulum phospholipid bilayer. Transporters for phosphatidylcholine and metabolites. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)49283-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Neumüller W, Fleer EA, Unger C, Eibl H. Enzymatic acylation of ether and ester lysophospholipids in rat liver microsomes. Lipids 1987; 22:808-12. [PMID: 3444370 DOI: 10.1007/bf02535535] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The acylation of lysophospholipids by rat liver acyltransferases was studied. A comparison between ester and ether lysophospholipids as substrates revealed large differences in substrate properties. For instance, oleic acid from oleoyl-CoA and arachidonic acid from arachidonoyl-CoA were not incorporated into 1-O-octadecyl-sn-glycero-3-phosphocholine under experimental conditions that allowed an optimal transfer of oleic acid and arachidonic acid to 1-O-palmitoyl-sn-glycero-3-phosphocholine. However, we observed an acyl-CoA-independent transfer of arachidonic acid from 1-O-stearoyl-2-O-arachidonoyl-sn-glycero-3-phosphoinositol to 1-O-octadecyl-sn-glycero-3-phosphocholine.
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Affiliation(s)
- W Neumüller
- Max-Planck-Institut für biophysikalische Chemie, Göttingen, Federal Republic of Germany
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24
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Arthur G, Page LL, Zaborniak CL, Choy PC. The acylation of lysophosphoradylglycerocholines in guinea-pig heart mitochondria. Biochem J 1987; 242:171-5. [PMID: 3036082 PMCID: PMC1147679 DOI: 10.1042/bj2420171] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The importance of the deacylation-reacylation pathway for attaining the desired fatty acid composition in microsomal phospholipids has been well established. It is not clear, however, whether this mechanism is of equal importance in mitochondria. The absence of acyltransferase activity in mammalian heart mitochondria has been reported in a number of studies. In the present study we report the presence of acyltransferase activities for lysophosphoradylglycerocholines in guinea-pig heart mitochondria. This enzyme showed properties that were considerably different from those of the microsomal enzymes. Of all the acyl-CoAs tested (C18:0, C18:1, C18:2 and C20:4) the mitochondrial enzyme utilized only linoleoyl-CoA as fatty acyl donor and utilized both 1-acyl-sn-glycero-3-phosphocholine and 1-alkenyl-sn-glycero-3-phosphocholine as fatty acyl acceptors. The presence of significant quantities of fatty acids other than linoleate at the C-2 position of mitochondrial acylglycerophosphocholines, coupled with the specificity of the enzyme for linoleoyl-CoA, suggest that, in addition to reacylation, other mechanisms play a significant role in producing the molecular composition of these phospholipids found in the mitochondria.
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25
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Burrier RE, Brecher P. Binding of lysophosphatidylcholine to the rat liver fatty acid binding protein. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 879:229-39. [PMID: 3768402 DOI: 10.1016/0005-2760(86)90107-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In this study, lysophosphatidylcholine (lysoPC) was shown to bind to a fatty acid binding protein isolated from rat liver. To demonstrate the binding, lysoPC was incorporated into multilamellar liposomes and incubated with protein. For comparison, binding of both lysoPC and fatty acid to liver fatty acid binding protein, albumin, and heart fatty acid binding protein were measured. At conditions where palmitic acid bound to liver fatty acid binding protein and albumin at ligand to protein molar ratios of 2:1 and 5:1, respectively, lysoPC binding occurred at molar ratios of 0.4:1 and 1:1. LysoPC did not bind to heart fatty acid binding protein under conditions where fatty acid bound at a molar ratio of 2:1. Competition experiments between lysoPC and fatty acid to liver fatty acid binding protein indicated separate binding sites for each ligand. An equilibrium dialysis cell was used to demonstrate that liver fatty acid binding protein was capable of transporting lysoPC from liposomes to rat liver microsomes, thereby facilitating its metabolism. These studies suggest that liver fatty acid binding protein may be involved in the intracellular metabolism of lysoPC as well as fatty acids, and that functional differences may exist between rat liver and heart fatty acid binding protein.
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26
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Nakagawa Y, Waku K, Hirose A, Kawashima Y, Kozuka H. Effect of clofibric acid on the molecular species composition of diacyl glycerophosphocholine of rat liver microsomes. Lipids 1986; 21:634-8. [PMID: 2879207 DOI: 10.1007/bf02537212] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of administering p-chlorophenoxyisobutyric (clofibric) acid to rats on the molecular species composition of diacyl-glycerophosphocholine (GPC) of rat liver microsomes was studied. Microsomal choline glycerophospholipids were converted to 1,2-diradyl-3-acetylglycerol and were separated into molecular species by reverse-phase high performance liquid chromatography. Diacyl-GPC consisted of 17 different molecular species. The predominant species were arachidonoyl derivatives, such as 18:0-20:4 (22.2% of the total) and 16:0-20:4 (22.0%). Administration of clofibric acid to rats caused a marked increase in 16:0-18:1 species of diacyl-GPC from 8% to 30%, making these the predominant species of diacyl-GPC in clofibric acid-fed rats. Also, a significant decrease (50% of controls) in 18:0-18:2 and 18:0-20:4 species was observed, whereas the decrease in molecular species containing 16:0 at the 1-position such as 16:0-18:2 and 16:0-20:4 was small (approximately 85% of control). The results show that clofibric acid caused marked changes in the molecular species composition of diacyl-GPC. The participation of 1-acyl-GPC acyltransferase and stearoyl-CoA desaturase in the regulation of the molecular species composition of diacyl-GPC is discussed.
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27
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Eibl H, Woolley P. Synthesis of enantiomerically pure glyceryl esters and ethers. I. Methods employing the precursor 1,2-isopropylidene-sn-glycerol. Chem Phys Lipids 1986. [DOI: 10.1016/0009-3084(86)90124-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Farahbakhsh ZT, Deamer DW, Lee NM, Loh HH. Enzymatic reconstitution of brain membrane and membrane opiate receptors. J Neurochem 1986; 46:953-62. [PMID: 3005499 DOI: 10.1111/j.1471-4159.1986.tb13062.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new method using lysophosphatide and acyl-CoA as detergents has been used to solubilize the rat brain opiate receptor. After solubilization, lysophosphatide and acyl-CoA can be almost completely removed by an enzymatic reaction that uses an acyltransferase from rat liver microsomes and reconstitutes the solubilized receptor in membranous vesicles. Morphological studies performed with negative staining and freeze-fracture electron microscopy revealed that the general appearance and intramembrane particle distribution of fracture faces in the reconstituted membrane are similar to those of the native membrane; this indicates that hydrophobic protein components of the original membrane were incorporated during reconstitution. Reconstituted membrane, however, contained higher levels of phosphatidylcholine and lower levels of cholesterol. The activities of the membrane-bound enzymes Na+, K+-ATPase and Ca2+, Mg2+-ATPase in the reconstituted system were 24 and 3%, respectively, those of the native membrane. Although binding of opiate ligands to the reconstituted membrane was stereospecific and saturable, higher concentrations of some of the unlabeled ligands were required to inhibit binding of the radiolabeled ligands. These changes in receptor characteristics are likely due to changes in lipid composition, physical state, and/or distribution of the lipids in the reconstituted membrane bilayer. This conclusion is supported by an increase in the affinity of opiate ligands for reconstituted membrane after adjustment of the latter's lipid composition to match more closely that of the original membrane. This was accomplished by treatment with phospholipid exchange protein to remove the excess phosphatidylcholine and by incorporation of cholesterol into the reconstituted membrane.
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29
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Yoichi K, Akihiko H, Toshiyuki A, Hiroshi K. Role of stearoyl-CoA desaturase and 1-acylglycerophosphorylcholine acyltransferase in the regulation of the acyl composition of phosphatidylcholine in rat liver. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/0005-2760(85)90045-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Kohji U, Hiromi H, Atsuko M, Harumi O. Effect of a high cholesterol diet on lipid metabolizing enzymes in spontaneously hypertensive rats. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/0005-2760(85)90240-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Kawashima Y, Hirose A, Kozuka H. Modification by clofibric acid of acyl composition of glycerolipids in rat liver. Possible involvement of fatty acid chain elongation and desaturation. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 795:543-51. [PMID: 6477960 DOI: 10.1016/0005-2760(84)90184-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Administration of p-chlorophenoxyisobutyric acid (clofibric acid) to rats induced a marked change in acyl composition of hepatic glycerolipids; a considerable increase in the proportion of octadecenoic acid (18:1) was accompanied by a marked decrease in the proportion of octadecadienoic acid (18:2). Among the glycerolipids, the changes in the proportions of 18:1 and 18:2 were the most marked in phosphatidylcholine. The change in the acyl composition of phosphatidylcholine paralleled the change in free fatty acid composition in microsomes. The treatment of rats with clofibric acid resulted in a 2.3-fold increase in activity of microsomal palmitoyl-CoA chain elongation and a 4.8-fold increase in activity of stearoyl-CoA desaturation. The activities of acyl-CoA synthetase, 1-acylglycerophosphate acyltransferase and 1-acylglycerophosphorylcholine acyltransferase in hepatic microsomes were increased approx. 3-, 1.7- and 3.6-times, respectively, by the treatment of rats with clofibric acid. These findings are discussed with respect to the role of fatty acid modification systems in the regulation of acyl composition of phosphatidylcholine.
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32
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Savolainen MJ, Baraona E, Pikkarainen P, Lieber CS. Hepatic triacylglycerol synthesizing activity during progression of alcoholic liver injury in the baboon. J Lipid Res 1984. [DOI: 10.1016/s0022-2275(20)37745-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Inoue M, Murase S, Okuyama H. Acyl coenzyme a:phospholipid acyltransferases in porcine platelets discriminate between omega-3 and omega-6 unsaturated fatty acids. Arch Biochem Biophys 1984; 231:29-37. [PMID: 6721500 DOI: 10.1016/0003-9861(84)90359-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The properties of porcine platelet acyltransferases which catalyze the incorporation of unsaturated fatty acids into the 2 positions of phospholipids were compared with those of porcine liver microsomes and rat liver microsomes. There were significant differences in the relative rates of incorporation of acyl groups into phospholipids as catalyzed by the membranes from different species and organs. The 1-acylglycerophosphate acyltransferase system showed relatively broad specificity for saturated and unsaturated fatty acids, with 14- to 20-carbon chains, while unsaturated acyl-CoAs with 18- and 20-carbon chains were generally good substrates in the acylations of 1-acylglycerophosphocholine and 1-acylglycerophosphoinositol. omega-3 and omega-6 unsaturated fatty acids were recognized differently by different acyltransferase systems in platelets. When activities for combinations of omega-3 and omega-6 unsaturated acyl-CoAs with the same number of carbons and with similar number of double bonds were compared, omega-6 fatty acids were relatively more preferred substrates than omega-3 fatty acids for the 1-acylglycerophosphoinositol acyltransferase system as compared with 1-acylglycerophosphocholine acyltransferase system.
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34
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36
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Haldar D, Kelker HC, Pullman ME. Properties of acyl coenzyme A: 1-acyl-sn-glycerol 3-phosphate acyltransferase from rat liver mitochondria and microsomes. TRANSACTIONS OF THE NEW YORK ACADEMY OF SCIENCES 1983; 41:173-82. [PMID: 6599355 DOI: 10.1111/j.2164-0947.1983.tb02799.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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37
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Der OM, Sun GY. Acylation of lysoglycerophospholipids by adrenal membranes. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1983; 15:615-9. [PMID: 6862076 DOI: 10.1016/0020-711x(83)90184-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
1. Substantial differences were found in the acyl donor and lyso-acceptor specificities among subcellular membranes and with respect to different regions of the adrenal gland. 2. In the presence of Mg2+-ATP and CoASH, adrenal microsomes were actively transferring arachidonate to lysophospholipids with acyl acceptor specificity in the order: 1-acyl-GPI greater than 1-acyl-GPC greater than 1-acyl-GP. However, when oleoyl-CoA was used, acyl acceptor specificity for the microsomal transferases was in the order: 1-acyl-GPC greater than 1-acyl-GP greater than 1-acyl-GPI. 3. Mitochondrial membranes had very low acyl transfer activity and they preferred 1-acyl-GPC over other lyso-acceptors. 4. The chromaffin granules were apparently lacking this type of activity.
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38
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39
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Chaudhary LR. The acylation of lysophosphatidylcholine in the rat testicular tissue: the combined activity of acyl-CoA synthetase and lysolecithin acyltransferase. Biochimie 1982; 64:211-7. [PMID: 6821159 DOI: 10.1016/s0300-9084(82)80471-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The activity of lysophosphatidylcholine acyltransferase (EC 2.3.1.23) in combination with acyl-CoA synthetase (EC 6.2.1.3) has been determined in the homogenates and subcellular fractions of rat testis. The enzyme activity was found to be maximal at pH 7.4 ATP and CoASH were required for optimal incorporation of [1-14C] oleic acid into phosphatidylcholine. The sulfhydryl-binding reagents showed inhibitory effect on the acyltransferase activity. Dibutyryl cyclic AMP and beta-mercaptoethanol did not affect the enzyme activity. Subcellular distribution patterns of markers, marker enzymes and lysolecithin acyltransferase have shown that the acyltransferase activity was found to be predominantly localized in the microsomal fraction, though significant activity was also present in the mitochondrial fraction. These findings, together with our previous studies on testicular phospholipases A, suggest that the deacylation-reacylation cycle is operative in rat testicular tissue.
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40
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Goldsmith PK. Postnatal development of some membrane-bound enzymes of rat liver and kidney. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 672:45-56. [PMID: 6260225 DOI: 10.1016/0304-4165(81)90278-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. The development of rat liver acyl-CoA:sn-glycerol-3-phosphate-O-acyl-transferase (EC 2.3.1.15) is characterized by an increase and decrease in activity during the neonatal period, followed by a second increase and decrease during the late weaning period. Kidney acyltransferase exhibits a similar peak in activity during the neonatal period before increasing to adult levels of activity during the late weaning period. 2. Nucleosidediphosphatase activity increases rapidly during the neonatal period and thereafter gradually rises to adult levels in both liver and kidney. The latency of the enzyme increases rapidly after birth and thereafter shows little change with age. The enzyme appears to be more latent in the liver than in the kidney at all ages studied. 3. NADPH-cytochrome c reductase of liver has a single steep maximum and minimum in activity during the neonatal period, before increasing again to adult levels during the late weaning period. The enzyme in kidney shows a similar developmental pattern but at much lower levels of specific activity. 4. sn-Glycerol-3-phosphate acyltransferase activity was significantly higher in rough than in smooth membranes throughout the neonatal period of rapid smooth membrane proliferation. This distribution of enzyme activity is unlike that reported by others in phenobarbital-induced smooth membrane proliferation and suggests a major role for rough membranes in phospholipid synthesis during the neonatal period. 5. The qualitative similarity in development in rough and smooth microsomal subfractions for each of these enzymes is in distinct contrast with results previously reported for glucose-6-phosphatase.
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41
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Kako KJ, Peckett SD. Effect of high fat/high erucic acid diet on phosphatidate synthesis and phosphatidate phosphatase in the subcellular fractions of rat heart and liver. Lipids 1981; 16:23-9. [PMID: 6261075 DOI: 10.1007/bf02534917] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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43
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Chakravarti DN, Chakravarti B, Chakrabarti P. Studies on phospholipase activities in Neurospora crassa mycelia. Lipids 1980; 15:830-7. [PMID: 6449646 DOI: 10.1007/bf02534373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Phospholipase A activity has been detected in mycelial homogenate of Neurospora crassa. A submycelial fraction, obtained by differential centrifugation containing the highest specific activity of phospholipase A has been shown to contain ca. 66% phospholipase A and 34% phospholipase A activity along with lysophospholipase and degergent-stimulated phospholipase D activity. Phospholipase A activity bound to N. crassa mycelia also has been observed.
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44
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Waku K, Hayakawa F, Nakazawa Y. The effect of cadmium ions and cadmium-metallothionein on the activities of phospholipid-synthesizing enzymes of rat liver microsomes in vitro. Arch Biochem Biophys 1980; 204:288-93. [PMID: 7425641 DOI: 10.1016/0003-9861(80)90035-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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45
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Fisher SK, Rowe CE. The acylation of lysophosphatidylcholine by subcellular fractions of guinea-pig cerebral cortex. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 618:231-41. [PMID: 7378436 DOI: 10.1016/0005-2760(80)90029-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The acylation of lysophosphatidylcholine by isolated subcellular fractions of guinea-pig cerebral cortex has been determined. The microsomal fraction contained the highest acylation activity, in terms of both specific and total activity. In all particulate fractions, including synaptic plasma membrane and mitochondria, there was a high correlation (correlation coefficient r = 0.90; P less than 0.001) between acylation and the activity of the microsomal enzyme, NADPH-cytochrome c reductase. No correlation existed between acylation and the activities of (Na+ + K+)-ATPase, acetylcholinesterase or succinate dehydrogenase. Acyl-CoA synthetase and lysophosphatidylcholine/acyltransferase, the individual enzymes responsible for acylation were enriched in the microsomal fraction. The activities of both enzymes in subcellular fractions correlated well with those of NADPH-cytochrome c reductase, with the exception that acyl-CoA synthetase activity in the mitochondrial fraction was largely independent of endoplasmic reticulum. Neither synaptic plasma membranes nor mitochondria appeared to possess significant amounts of acyltransferase activity. The results indicate that the acylation of lysophosphatidylcholine is confined to the endoplasmic reticulum, and that activity present in the synaptic plasma membrane or mitochondrial fraction is attributable to microsomal contamination.
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46
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Abstract
Acyltransferase activity is present in a variety of membranes species, including liver microsomes. The substrates of this enzyme are lysophosphatides and acyl CoA derivatives. We have found that the detergent effect of these substrates can be used to solubilize rat liver microsomes. If the solubilized fraction in incubated, the acyltransferase acylates the lysophosphatide and thereby degrades the detergent effect so that vesicular membranes re-form. Gel electrophoresis patterns show that the reconstituted membranes contain all of the major protein components of the original microsomes. A marker enzyme for liver microsomes, NADPH-cytochrome c reductase, was present in the reconstituted membranes at 70% of the specific activity in the original microsomes, and freeze-fracture electron microscopy showed intramembrane particles on all fracture faces. The system may provide a useful model for studies particles on all fracture faces. This system may provide a useful model for studies of certain membrane biogenesis reactions that utilize acyltransferase in vivo.
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47
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The acylation of sn-glycerol 3-phosphate in mammalian organs and Ehrlich ascites tumor cells. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(17)30039-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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48
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Morré DJ, Kartenbeck J, Franke WW. Membrane flow and intercoversions among endomembranes. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 559:71-52. [PMID: 375982 DOI: 10.1016/0304-4157(79)90008-x] [Citation(s) in RCA: 227] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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49
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Possmayer F, Kleine L, Duwe G, Stewart-DeHaan PJ, Wong T, MacPherson CF, Harding PG. Differences in the subcellular and subsynaptosomal distribution of the putative endoplasmic reticulum markers, NADPH-cytochrome c reductase, estrone sulfate sulfohydrolase and CDP-choline-diacylglycerol cholinephosphotransferase in rat brain. J Neurochem 1979; 32:889-906. [PMID: 219149 DOI: 10.1111/j.1471-4159.1979.tb04573.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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50
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Magargal W, Dickinson E, Slakey L. Distribution of membrane marker enzymes in cultured arterial endothelial and smooth muscle cells. The subcellular location of oleoyl-CoA:1-acyl-sn-glycero-3-phosphocholine acyltransferase. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34398-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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