1
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Kjølbye LR, Sørensen L, Yan J, Berglund NA, Ferkinghoff-Borg J, Robinson CV, Schiøtt B. Lipid Modulation of a Class B GPCR: Elucidating the Modulatory Role of PI(4,5)P 2 Lipids. J Chem Inf Model 2022; 62:6788-6802. [PMID: 36036575 DOI: 10.1021/acs.jcim.2c00635] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) lipids have been shown to stabilize an active conformation of class A G-protein coupled receptors (GPCRs) through a conserved binding site, not present in class B GPCRs. For class B GPCRs, previous molecular dynamics (MD) simulation studies have shown PI(4,5)P2 interacting with the Glucagon receptor (GCGR), which constitutes an important target for diabetes and obesity therapeutics. In this work, we applied MD simulations supported by native mass spectrometry (nMS) to study lipid interactions with GCGR. We demonstrate how tail composition plays a role in modulating the binding of PI(4,5)P2 lipids to GCGR. Specifically, we find the PI(4,5)P2 lipids to have a higher affinity toward the inactive conformation of GCGR. Interestingly, we find that in contrast to class A GPCRs, PI(4,5)P2 appear to stabilize the inactive conformation of GCGR through a binding site conserved across class B GPCRs but absent in class A GPCRs. This suggests differences in the regulatory function of PI(4,5)P2 between class A and class B GPCRs.
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Affiliation(s)
- Lisbeth R Kjølbye
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.,Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Lars Sørensen
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Jun Yan
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Nils A Berglund
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | | | - Carol V Robinson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds vej 14, 8000 Aarhus C, Denmark
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2
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Han X, Gross RW. The foundations and development of lipidomics. J Lipid Res 2022; 63:100164. [PMID: 34953866 PMCID: PMC8953652 DOI: 10.1016/j.jlr.2021.100164] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/15/2022] Open
Abstract
For over a century, the importance of lipid metabolism in biology was recognized but difficult to mechanistically understand due to the lack of sensitive and robust technologies for identification and quantification of lipid molecular species. The enabling technological breakthroughs emerged in the 1980s with the development of soft ionization methods (Electrospray Ionization and Matrix Assisted Laser Desorption/Ionization) that could identify and quantify intact individual lipid molecular species. These soft ionization technologies laid the foundations for what was to be later named the field of lipidomics. Further innovative advances in multistage fragmentation, dramatic improvements in resolution and mass accuracy, and multiplexed sample analysis fueled the early growth of lipidomics through the early 1990s. The field exponentially grew through the use of a variety of strategic approaches, which included direct infusion, chromatographic separation, and charge-switch derivatization, which facilitated access to the low abundance species of the lipidome. In this Thematic Review, we provide a broad perspective of the foundations, enabling advances, and predicted future directions of growth of the lipidomics field.
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Affiliation(s)
- Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; Departments of Medicine - Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Richard W Gross
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA; Department of Chemistry, Washington University, St. Louis, MO, USA
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3
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Jennings W, Epand RM. CDP-diacylglycerol, a critical intermediate in lipid metabolism. Chem Phys Lipids 2020; 230:104914. [PMID: 32360136 DOI: 10.1016/j.chemphyslip.2020.104914] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/01/2020] [Accepted: 04/13/2020] [Indexed: 12/13/2022]
Abstract
The roles of lipids expand beyond the basic building blocks of biological membranes. In addition to forming complex and dynamic barriers, the thousands of different lipid species in the cell contribute to essentially all the processes of life. Specific lipids are increasingly identified in cellular processes, including signal transduction, membrane trafficking, metabolic control and protein regulation. Tight control of their synthesis and degradation is essential for homeostasis. Most of the lipid molecules in the cell originate from a small number of critical intermediates. Thus, regulating the synthesis of intermediates is essential for lipid homeostasis and optimal biological functions. Cytidine diphosphate diacylglycerol (CDP-DAG) is an intermediate which occupies a branch point in lipid metabolism. CDP-DAG is incorporated into different synthetic pathways to form distinct phospholipid end-products depending on its location of synthesis. Identification and characterization of CDP-DAG synthases which catalyze the synthesis of CDP-DAG has been hampered by difficulties extracting these membrane-bound enzymes for purification. Recent developments have clarified the cellular localization of the CDP-DAG synthases and identified a new unrelated CDP-DAG synthase enzyme. These findings have contributed to a deeper understanding of the extensive synthetic and signaling networks stemming from this key lipid intermediate.
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Affiliation(s)
- William Jennings
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
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4
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Niu Y, Xiang Y. An Overview of Biomembrane Functions in Plant Responses to High-Temperature Stress. FRONTIERS IN PLANT SCIENCE 2018; 9:915. [PMID: 30018629 PMCID: PMC6037897 DOI: 10.3389/fpls.2018.00915] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/08/2018] [Indexed: 05/03/2023]
Abstract
Biological membranes are highly ordered structures consisting of mosaics of lipids and proteins. Elevated temperatures can directly and effectively change the properties of these membranes, including their fluidity and permeability, through a holistic effect that involves changes in the lipid composition and/or interactions between lipids and specific membrane proteins. Ultimately, high temperatures can alter microdomain remodeling and instantaneously relay ambient cues to downstream signaling pathways. Thus, dynamic membrane regulation not only helps cells perceive temperature changes but also participates in intracellular responses and determines a cell's fate. Moreover, due to the specific distribution of extra- and endomembrane elements, the plasma membrane (PM) and membranous organelles are individually responsible for distinct developmental events during plant adaptation to heat stress. This review describes recent studies that focused on the roles of various components that can alter the physical state of the plasma and thylakoid membranes as well as the crucial signaling pathways initiated through the membrane system, encompassing both endomembranes and membranous organelles in the context of heat stress responses.
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Affiliation(s)
- Yue Niu
- *Correspondence: Yue Niu, Yun Xiang,
| | - Yun Xiang
- *Correspondence: Yue Niu, Yun Xiang,
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5
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Kania-Korwel I, Wu X, Wang K, Lehmler HJ. Identification of lipidomic markers of chronic 3,3',4,4',5-pentachlorobiphenyl (PCB 126) exposure in the male rat liver. Toxicology 2017; 390:124-134. [PMID: 28890136 PMCID: PMC5633524 DOI: 10.1016/j.tox.2017.09.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 12/14/2022]
Abstract
Exposure to PCB 126, an environmentally relevant aryl hydrocarbon receptor agonist, is an environmental factor causing hepatic steatosis in rodent models; however, the lipidome of PCB 126-exposed rats has not been investigated in-depth. The objective of the present study was therefore to characterize dose-dependent changes in the lipid profile in the liver of male Sprague-Dawley rats exposed to PCB 126. Rats were exposed for three month to intraperitoneal injections of 0.01, 0.05 and 0.2μmol/kg bw PCB 126 in corn oil. Control animals were exposed in parallel and received corn oil alone. Lipids were extracted from whole liver homogenate and levels of polar lipids and fatty acids incorporated into triglycerides (FATAGs) were determined with tandem mass spectrometry using electrospray ionization. PCB 126 exposure increased the hepatic content of polar lipids and FATAGs. Protein adjusted levels of several polar lipid classes, in particular phosphatidylserine levels, decreased, whereas FATAGs levels typically increased with increasing PCB 126 dose. Sensitive, dose-dependent endpoints of PCB 126 exposure included an increase in levels of adrenic acid incorporated into triglycerides and changes in levels of certain ether-linked phospholipid and 1-alkyl/1-alkenyldiacylglycerol species, as determined using partial least square discriminant analysis (PLS-DA) and ANOVA. These changes in the composition of polar lipids and fatty acid in the liver of PCB 126 exposed rats identified several novel markers of PCB 126-mediated fatty liver disease that need to be validated in further studies.
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Affiliation(s)
- Izabela Kania-Korwel
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Xianai Wu
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Hans-Joachim Lehmler
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA.
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6
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Wang M, Palavicini JP, Cseresznye A, Han X. Strategy for Quantitative Analysis of Isomeric Bis(monoacylglycero)phosphate and Phosphatidylglycerol Species by Shotgun Lipidomics after One-Step Methylation. Anal Chem 2017; 89:8490-8495. [PMID: 28708380 DOI: 10.1021/acs.analchem.7b02058] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Understanding the cellular function and metabolism of bis(monoacylglycero)phosphate (BMP), an important but low-abundance class of phospholipids, has been hindered due to its difficulties to be resolved from its structural isomer (i.e., phosphatidylglycerol, PG, another low-abundance class of phospholipids). A novel strategy for quantitative analysis of BMP and PG species was developed after one-step methylation of lipid extracts in combination with high mass accuracy/resolution mass spectrometry after direct infusion (i.e., shotgun lipidomics). The novel strategy was applied for quantitative analysis of mouse hepatic BMP and PG species and their changes induced by long-term high-fat diet (HFD) feeding. Interestingly, we revealed that HFD-fed mice display a dramatic accumulation of hepatic BMP compared to chow-fed littermates. We believe the development of this novel strategy could greatly facilitate our understanding of the role of BMP in biological systems.
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Affiliation(s)
- Miao Wang
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute , Orlando, Florida 32827, United States
| | - Juan Pablo Palavicini
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute , Orlando, Florida 32827, United States
| | - Adam Cseresznye
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute , Orlando, Florida 32827, United States
| | - Xianlin Han
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute , Orlando, Florida 32827, United States
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7
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Fujimoto T, Parmryd I. Interleaflet Coupling, Pinning, and Leaflet Asymmetry-Major Players in Plasma Membrane Nanodomain Formation. Front Cell Dev Biol 2017; 4:155. [PMID: 28119914 PMCID: PMC5222840 DOI: 10.3389/fcell.2016.00155] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/27/2016] [Indexed: 01/26/2023] Open
Abstract
The plasma membrane has a highly asymmetric distribution of lipids and contains dynamic nanodomains many of which are liquid entities surrounded by a second, slightly different, liquid environment. Contributing to the dynamics is a continuous repartitioning of components between the two types of liquids and transient links between lipids and proteins, both to extracellular matrix and cytoplasmic components, that temporarily pin membrane constituents. This make plasma membrane nanodomains exceptionally challenging to study and much of what is known about membrane domains has been deduced from studies on model membranes at equilibrium. However, living cells are by definition not at equilibrium and lipids are distributed asymmetrically with inositol phospholipids, phosphatidylethanolamines and phosphatidylserines confined mostly to the inner leaflet and glyco- and sphingolipids to the outer leaflet. Moreover, each phospholipid group encompasses a wealth of species with different acyl chain combinations whose lateral distribution is heterogeneous. It is becoming increasingly clear that asymmetry and pinning play important roles in plasma membrane nanodomain formation and coupling between the two lipid monolayers. How asymmetry, pinning, and interdigitation contribute to the plasma membrane organization is only beginning to be unraveled and here we discuss their roles and interdependence.
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Affiliation(s)
- Toyoshi Fujimoto
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Japan
| | - Ingela Parmryd
- Science for Life Laboratory, Medical Cell Biology, Uppsala University Uppsala, Sweden
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8
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Acharjee A, Ament Z, West JA, Stanley E, Griffin JL. Integration of metabolomics, lipidomics and clinical data using a machine learning method. BMC Bioinformatics 2016; 17:440. [PMID: 28185575 PMCID: PMC5133491 DOI: 10.1186/s12859-016-1292-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The recent pandemic of obesity and the metabolic syndrome (MetS) has led to the realisation that new drug targets are needed to either reduce obesity or the subsequent pathophysiological consequences associated with excess weight gain. Certain nuclear hormone receptors (NRs) play a pivotal role in lipid and carbohydrate metabolism and have been highlighted as potential treatments for obesity. This realisation started a search for NR agonists in order to understand and successfully treat MetS and associated conditions such as insulin resistance, dyslipidaemia, hypertension, hypertriglyceridemia, obesity and cardiovascular disease. The most studied NRs for treating metabolic diseases are the peroxisome proliferator-activated receptors (PPARs), PPAR-α, PPAR-γ, and PPAR-δ. However, prolonged PPAR treatment in animal models has led to adverse side effects including increased risk of a number of cancers, but how these receptors change metabolism long term in terms of pathology, despite many beneficial effects shorter term, is not fully understood. In the current study, changes in male Sprague Dawley rat liver caused by dietary treatment with a PPAR-pan (PPAR-α, -γ, and -δ) agonist were profiled by classical toxicology (clinical chemistry) and high throughput metabolomics and lipidomics approaches using mass spectrometry. RESULTS In order to integrate an extensive set of nine different multivariate metabolic and lipidomics datasets with classical toxicological parameters we developed a hypotheses free, data driven machine learning approach. From the data analysis, we examined how the nine datasets were able to model dose and clinical chemistry results, with the different datasets having very different information content. CONCLUSIONS We found lipidomics (Direct Infusion-Mass Spectrometry) data the most predictive for different dose responses. In addition, associations with the metabolic and lipidomic data with aspartate amino transaminase (AST), a hepatic leakage enzyme to assess organ damage, and albumin, indicative of altered liver synthetic function, were established. Furthermore, by establishing correlations and network connections between eicosanoids, phospholipids and triacylglycerols, we provide evidence that these lipids function as a key link between inflammatory processes and intermediary metabolism.
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Affiliation(s)
- Animesh Acharjee
- Medical Research Council, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK.,The Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Zsuzsanna Ament
- Medical Research Council, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK
| | - James A West
- Medical Research Council, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK
| | - Elizabeth Stanley
- Medical Research Council, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK
| | - Julian L Griffin
- Medical Research Council, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK. .,The Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
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9
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Kimura T, Jennings W, Epand RM. Roles of specific lipid species in the cell and their molecular mechanism. Prog Lipid Res 2016; 62:75-92. [PMID: 26875545 DOI: 10.1016/j.plipres.2016.02.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/04/2016] [Accepted: 02/10/2016] [Indexed: 12/19/2022]
Abstract
Thousands of different molecular species of lipids are present within a single cell, being involved in modulating the basic processes of life. The vast number of different lipid species can be organized into a number of different lipid classes, which may be defined as a group of lipids with a common chemical structure, such as the headgroup, apart from the nature of the hydrocarbon chains. Each lipid class has unique biological roles. In some cases, a relatively small change in the headgroup chemical structure can result in a drastic change in function. Such phenomena are well documented, and largely understood in terms of specific interactions with proteins. In contrast, there are observations that the entire structural specificity of a lipid molecule, including the hydrocarbon chains, is required for biological activity through specific interactions with membrane proteins. Understanding of these phenomena represents a fundamental change in our thinking of the functions of lipids in biology. There are an increasing number of diverse examples of roles for specific lipids in cellular processes including: Signal transduction; trafficking; morphological changes; cell division. We are gaining knowledge and understanding of the underlying molecular mechanisms. They are of growing importance in both basic and applied sciences.
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Affiliation(s)
- Tomohiro Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - William Jennings
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
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10
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Fujimoto T, Parmryd I. Interleaflet Coupling, Pinning, and Leaflet Asymmetry-Major Players in Plasma Membrane Nanodomain Formation. Front Cell Dev Biol 2016. [PMID: 28119914 DOI: 10.3389/fcell.2016.0015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
The plasma membrane has a highly asymmetric distribution of lipids and contains dynamic nanodomains many of which are liquid entities surrounded by a second, slightly different, liquid environment. Contributing to the dynamics is a continuous repartitioning of components between the two types of liquids and transient links between lipids and proteins, both to extracellular matrix and cytoplasmic components, that temporarily pin membrane constituents. This make plasma membrane nanodomains exceptionally challenging to study and much of what is known about membrane domains has been deduced from studies on model membranes at equilibrium. However, living cells are by definition not at equilibrium and lipids are distributed asymmetrically with inositol phospholipids, phosphatidylethanolamines and phosphatidylserines confined mostly to the inner leaflet and glyco- and sphingolipids to the outer leaflet. Moreover, each phospholipid group encompasses a wealth of species with different acyl chain combinations whose lateral distribution is heterogeneous. It is becoming increasingly clear that asymmetry and pinning play important roles in plasma membrane nanodomain formation and coupling between the two lipid monolayers. How asymmetry, pinning, and interdigitation contribute to the plasma membrane organization is only beginning to be unraveled and here we discuss their roles and interdependence.
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Affiliation(s)
- Toyoshi Fujimoto
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Japan
| | - Ingela Parmryd
- Science for Life Laboratory, Medical Cell Biology, Uppsala University Uppsala, Sweden
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11
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Bradley RM, Marvyn PM, Aristizabal Henao JJ, Mardian EB, George S, Aucoin MG, Stark KD, Duncan RE. Acylglycerophosphate acyltransferase 4 (AGPAT4) is a mitochondrial lysophosphatidic acid acyltransferase that regulates brain phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol levels. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1566-76. [DOI: 10.1016/j.bbalip.2015.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/18/2015] [Accepted: 09/24/2015] [Indexed: 10/23/2022]
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12
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Kassenböhmer R, Draude F, Körsgen M, Pelster A, Arlinghaus HF. Calculation of Membrane Lipid Ratios Using Single-Pixel Time-of-Flight Secondary Ion Mass Spectrometry Analysis. Anal Chem 2015; 87:7795-802. [PMID: 26146009 DOI: 10.1021/acs.analchem.5b01456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Much evidence suggests that membrane domains, termed lipid rafts, which are enriched in sphingomyeline and cholesterol play important roles in the regulation of physiological and pathophysiological processes. A label-free quantitative imaging method for lipids is lacking at present. We report an algorithm which enables us to identify and calculate the percentages of the ingredients of lipid mixtures from single-pixel time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra in model systems. The algorithm is based on a linear mixing model. Discriminant analysis is used to reduce the dimension of the data space. Calculations were separately performed for positive and negative ion mass spectra. Phosphatidylcholine and sphingomyeline which have identical headgroups and cannot be easily distinguished from another by positive ion mass spectra were included in the analysis. The algorithm outlined may more generally be used to calculate the percentages of ingredients of mixtures from spectra acquired by quite different methods such as X-ray photoelectron spectroscopy.
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Affiliation(s)
- Rainer Kassenböhmer
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Felix Draude
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Martin Körsgen
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Andreas Pelster
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Heinrich F Arlinghaus
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
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13
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Eichmann TO, Lass A. DAG tales: the multiple faces of diacylglycerol--stereochemistry, metabolism, and signaling. Cell Mol Life Sci 2015; 72:3931-52. [PMID: 26153463 PMCID: PMC4575688 DOI: 10.1007/s00018-015-1982-3] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/17/2015] [Accepted: 06/29/2015] [Indexed: 12/31/2022]
Abstract
The neutral lipids diacylglycerols (DAGs) are involved in a plethora of metabolic pathways. They function as components of cellular membranes, as building blocks for glycero(phospho)lipids, and as lipid second messengers. Considering their central role in multiple metabolic processes and signaling pathways, cellular DAG levels require a tight regulation to ensure a constant and controlled availability. Interestingly, DAG species are versatile in their chemical structure. Besides the different fatty acid species esterified to the glycerol backbone, DAGs can occur in three different stereo/regioisoforms, each with unique biological properties. Recent scientific advances have revealed that DAG metabolizing enzymes generate and distinguish different DAG isoforms, and that only one DAG isoform holds signaling properties. Herein, we review the current knowledge of DAG stereochemistry and their impact on cellular metabolism and signaling. Further, we describe intracellular DAG turnover and its stereochemistry in a 3-pool model to illustrate the spatial and stereochemical separation and hereby the diversity of cellular DAG metabolism.
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Affiliation(s)
- Thomas Oliver Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010, Graz, Austria.
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010, Graz, Austria.
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14
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D'Souza K, Kim YJ, Balla T, Epand RM. Distinct properties of the two isoforms of CDP-diacylglycerol synthase. Biochemistry 2014; 53:7358-67. [PMID: 25375833 PMCID: PMC4255645 DOI: 10.1021/bi501250m] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
CDP-diacylglycerol
synthases (CDS) are critical enzymes that catalyze
the formation of CDP-diacylglycerol (CDP-DAG) from phosphatidic acid
(PA). Here we show in vitro that the two isoforms
of human CDS, CDS1 and CDS2, show different acyl chain specificities
for its lipid substrate. CDS2 is selective for the acyl chains at
the sn-1 and sn-2 positions, the
most preferred species being 1-stearoyl-2-arachidonoyl-sn-phosphatidic acid. CDS1, conversely, shows no particular substrate
specificity, displaying similar activities for almost all substrates
tested. Additionally, we show that inhibition of CDS2 by phosphatidylinositol
is also acyl chain-dependent, with the strongest inhibition seen with
the 1-stearoyl-2-arachidonoyl species. CDS1 shows no acyl chain-dependent
inhibition. Both CDS1 and CDS2 are inhibited by their anionic phospholipid
end products, with phosphatidylinositol-(4,5)-bisphosphate showing
the strongest inhibition. Our results indicate that CDS1 and CDS2
could create different CDP-DAG pools that may serve to enrich different
phospholipid species with specific acyl chains.
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Affiliation(s)
- Kenneth D'Souza
- Department of Biochemistry and Biomedical Sciences, McMaster University , Hamilton, Ontario L8N 3Z5, Canada
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15
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Lysophosphatidylcholine acyltransferase 3 is the key enzyme for incorporating arachidonic acid into glycerophospholipids during adipocyte differentiation. Int J Mol Sci 2012. [PMID: 23208369 PMCID: PMC3546689 DOI: 10.3390/ijms131216267] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cellular membranes contain glycerophospholipids, which have important structural and functional roles in cells. Glycerophospholipids are first formed in the de novo pathway (Kennedy pathway) and are matured in the remodeling pathway (Lands' cycle). Recently, lysophospholipid acyltransferases functioning in Lands' cycle were identified and characterized. Several enzymes involved in glycerophospholipid biosynthesis have been reported to have important roles in adipocytes. However, the role of Lands' cycle in adipogenesis has not yet been reported. Using C3H10T1/2, a cell line capable of differentiating to adipocyte-like cells in vitro, changes of lysophospholipid acyltransferase activities were investigated. Lysophosphatidylcholine acyltransferase (LPCAT), lysophosphatidylethanolamine acyltransferase (LPEAT) and lysophosphatidylserine acyltransferase (LPSAT) activities were enhanced, especially with 18:2-CoA and 20:4-CoA as donors. Correspondingly, mRNA expression of LPCAT3, which possesses LPCAT, LPEAT and LPSAT activities with high specificity for 18:2- and 20:4-CoA, was upregulated during adipogenesis. Analysis of acyl-chain compositions of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) showed a change in their profiles between preadipocytes and adipocytes, including an increase in the percentage of arachidonic acid-containing phospholipids. These changes are consistent with the activities of LPCAT3. Therefore, it is possible that enhanced phospholipid remodeling by LPCAT3 may be associated with adipocyte differentiation.
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Han X, Yang K, Gross RW. Multi-dimensional mass spectrometry-based shotgun lipidomics and novel strategies for lipidomic analyses. MASS SPECTROMETRY REVIEWS 2012; 31:134-78. [PMID: 21755525 PMCID: PMC3259006 DOI: 10.1002/mas.20342] [Citation(s) in RCA: 398] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 05/20/2011] [Accepted: 05/20/2011] [Indexed: 05/05/2023]
Abstract
Since our last comprehensive review on multi-dimensional mass spectrometry-based shotgun lipidomics (Mass Spectrom. Rev. 24 (2005), 367), many new developments in the field of lipidomics have occurred. These developments include new strategies and refinements for shotgun lipidomic approaches that use direct infusion, including novel fragmentation strategies, identification of multiple new informative dimensions for mass spectrometric interrogation, and the development of new bioinformatic approaches for enhanced identification and quantitation of the individual molecular constituents that comprise each cell's lipidome. Concurrently, advances in liquid chromatography-based platforms and novel strategies for quantitative matrix-assisted laser desorption/ionization mass spectrometry for lipidomic analyses have been developed. Through the synergistic use of this repertoire of new mass spectrometric approaches, the power and scope of lipidomics has been greatly expanded to accelerate progress toward the comprehensive understanding of the pleiotropic roles of lipids in biological systems.
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Affiliation(s)
- Xianlin Han
- Sanford-Burnham Medical Research Institute, Orlando, FL 32827, USA.
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17
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White NR, Burns PD, Cheatham RD, Romero RM, Nozykowski JP, Bruemmer JE, Engle TE. Fish meal supplementation increases bovine plasma and luteal tissue omega-3 fatty acid composition. J Anim Sci 2011; 90:771-8. [PMID: 22003234 DOI: 10.2527/jas.2011-4208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objective of this experiment was to determine if dietary inclusion of fish meal would increase plasma and luteal tissue concentrations of eicosapentaenoic and docosahexaenoic acids. Seventeen nonlactating Angus cows (2 to 8 yr of age) were housed in individual pens and fed a corn silage-based diet for approximately 60 d. Diets were supplemented with fish meal at 5% DMI (a rich source of eicosapentaenoic acid and docosahexaenoic acid; n = 9 cows) or corn gluten meal at 6% DMI (n = 8 cows). Body weights and jugular blood samples were collected immediately before the initiation of supplementation and every 7 d thereafter for 56 d to monitor plasma n-3 fatty acid composition and BW. Estrous cycles were synchronized using 2 injections of PGF(2α) administered at 14-d intervals. The ovary bearing the corpus luteum was surgically removed at midcycle (between d 10 and 12) after estrus synchronization, which corresponded to approximately d 60 of supplementation. The ovary was transported to the laboratory, and approximately 1.5 g of luteal tissue was stored at -80°C until analyzed for n-3 fatty acid content. Initial and ending BW did not differ (P > 0.10) between cows supplemented with fish meal and those with corn gluten meal. Plasma eicosapentaenoic acid was greater (P < 0.05) beginning at d 7 of supplementation and docosahexaenoic was greater (P < 0.05) beginning at d 14 of supplementation for cows receiving fish meal. Luteal tissue collected from fish meal-supplemented cows had greater (P < 0.05) luteal n-3 fatty acids and reduced (P < 0.05) arachidonic acid and n-6 to n-3 ratio as compared with tissue obtained from cows supplemented with corn gluten meal. Our data show that fish meal supplementation increases luteal n-3 fatty acid content and reduces available arachidonic acid content, the precursor for PGF(2α). The increase in luteal n-3 fatty acids may reduce PGF(2α) intraluteal synthesis after breeding resulting in increased fertility in cattle.
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Affiliation(s)
- N R White
- School of Biological Sciences, University of Northern Colorado, Greeley 80639, USA
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18
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Le Grand F, Kraffe E, Marty Y, Donaghy L, Soudant P. Membrane phospholipid composition of hemocytes in the Pacific oyster Crassostrea gigas and the Manila clam Ruditapes philippinarum. Comp Biochem Physiol A Mol Integr Physiol 2011; 159:383-91. [DOI: 10.1016/j.cbpa.2011.04.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 11/17/2022]
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19
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Le Guédard M, Bessoule JJ, Boyer V, Ayciriex S, Velours G, Kulik W, Ejsing CS, Shevchenko A, Coulon D, Lessire R, Testet E. PSI1 is responsible for the stearic acid enrichment that is characteristic of phosphatidylinositol in yeast. FEBS J 2009; 276:6412-24. [DOI: 10.1111/j.1742-4658.2009.07355.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Yuki K, Shindou H, Hishikawa D, Shimizu T. Characterization of mouse lysophosphatidic acid acyltransferase 3: an enzyme with dual functions in the testis. J Lipid Res 2008; 50:860-9. [PMID: 19114731 DOI: 10.1194/jlr.m800468-jlr200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glycerophospholipids are structural and functional components of cellular membranes as well as precursors of various lipid mediators. Using acyl-CoAs as donors, glycerophospholipids are formed by the de novo pathway (Kennedy pathway) and modified in the remodeling pathway (Lands' cycle). Various acyltransferases, including two lysophosphatidic acid acyltransferases (LPAATs), have been discovered from a 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family. Proteins of this family contain putative acyltransferase motifs, but their biochemical properties and physiological roles are not completely understood. Here, we demonstrated that mouse LPAAT3, previously known as mouse AGPAT3, possesses strong LPAAT activity and modest lysophosphatidylinositol acyltransferase activity with a clear preference for arachidonoyl-CoA as a donor. This enzyme is highly expressed in the testis, where CDP-diacylglycerol synthase 1 preferring 1-stearoyl-2-arachidonoyl-phosphatidic acid as a substrate is also highly expressed. Since 1-stearoyl-2-arachidonoyl species are the main components of phosphatidylinositol, mouse LPAAT3 may function in both the de novo and remodeling pathways and contribute to effective biogenesis of 1-stearoyl-2-arachidonoyl-phosphatidylinositol in the testis. Additionally, the expression of this enzyme in the testis increases significantly in an age-dependent manner, and beta-estradiol may be an important regulator of this enzyme's induction. Our findings identify this acyltransferase as an alternative important enzyme to produce phosphatidylinositol in the testis.
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Affiliation(s)
- Koichi Yuki
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Tokyo, Tokyo, Japan
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22
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Discovery of a lysophospholipid acyltransferase family essential for membrane asymmetry and diversity. Proc Natl Acad Sci U S A 2008; 105:2830-5. [PMID: 18287005 DOI: 10.1073/pnas.0712245105] [Citation(s) in RCA: 236] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
All organisms consist of cells that are enclosed by a cell membrane containing bipolar lipids and proteins. Glycerophospholipids are important not only as structural and functional components of cellular membrane but also as precursors of various lipid mediators. Polyunsaturated fatty acids comprising arachidonic acid or eicosapentaenoic acid are located at sn-2 position, but not at sn-1 position of glycerophospholipids in an asymmetrical manner. In addition to the asymmetry, the membrane diversity is important for membrane fluidity and curvature. To explain the asymmetrical distribution of fatty acids, the rapid turnover of sn-2 position was proposed in 1958 by Lands [Lands WE (1958) Metabolism of glycerolipides: A comparison of lecithin and triglyceride synthesis. J Biol Chem 231:883-888]. However, the molecular mechanisms and biological significance of the asymmetry remained unknown. Here, we describe a putative enzyme superfamily consisting mainly of three gene families, which catalyzes the transfer of acyl-CoAs to lysophospholipids to produce different classes of phospholipids. Among them, we characterized three important enzymes with different substrate specificities and tissue distributions; one, termed lysophosphatidylcholine acyltransferase-3 (a mammalian homologue of Drosophila nessy critical for embryogenesis), prefers arachidonoyl-CoA, and the other two enzymes incorporate oleoyl-CoAs to lysophosphatidylethanolamine and lysophosphatidylserine. Thus, we propose that the membrane diversity is produced by the concerted and overlapped reactions with multiple enzymes that recognize both the polar head group of glycerophospholipids and various acyl-CoAs. Our findings constitute a critical milestone for our understanding about how membrane diversity and asymmetry are established and their biological significance.
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23
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Kinsey GR, McHowat J, Patrick KS, Schnellmann RG. Role of Ca2+-independent phospholipase A2gamma in Ca2+-induced mitochondrial permeability transition. J Pharmacol Exp Ther 2007; 321:707-15. [PMID: 17312185 DOI: 10.1124/jpet.107.119545] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Our laboratory previously demonstrated Ca2+-independent phospholipase A2gamma (iPLA2gamma) is localized to mitochondria and that iPLA2 inhibition blocks cisplatin-induced caspase-mediated apoptosis. Whereas the mitochondrial permeability transition (MPT) is a key control point for apoptosis, the role of mitochondrial iPLA2gamma in MPT has not been established. In the present study, we addressed this issue. Ca2+-induced renal cortex mitochondrial (RCM) swelling was blocked by the MPT inhibitor cyclosporine A. The R-isomer of bromoenol lactone (R-BEL), which enantiospecifically inhibits iPLA2gamma, inhibited Ca2+-induced RCM MPT, whereas S-BEL (negative control) had no effect. Ca2+ treatment resulted in a significant increase in free arachidonic acid (AA) (>50 microM) in the RCM suspension that was blocked by pretreatment with BEL. No increases in free myristic, palmitic, stearic, oleic, linoleic, or docosahexaenoic acid were detected after Ca2+ treatment. The addition of AA (18 microM) to Ca2+-treated RCM with inhibited iPLA2gamma activity restored MPT. We also determined that RCM iPLA2gamma displays higher activity against plasmenylcholine with AA in the sn-2 position than oleic acid. Ca2+ exposure significantly increased RCM iPLA2gamma activity; however, the Ca2+-induced activation of iPLA2gamma was not the result of mitochondrial membrane potential dissipation, opening of the MPT pore, or mitochondrial swelling. Taken together these findings provide strong evidence that Ca2+-induced RCM MPT is mediated by iPLA2gamma-catalyzed AA liberation.
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Affiliation(s)
- Gilbert R Kinsey
- Medical University of South Carolina, Department of Pharmaceutical Sciences, 280 Calhoun St., Charleston, SC 29425, USA
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24
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Vaver VA, Ushakov AN. High temperature gas-liquid chromatography in lipid analysis. METHODS OF BIOCHEMICAL ANALYSIS 2006; 26:327-406. [PMID: 7392962 DOI: 10.1002/9780470110461.ch8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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25
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Pérez-Palacios T, Antequera T, Muriel E, Ruiz J. Stereospecific analysis of phospholipid classes in rat muscle. EUR J LIPID SCI TECH 2006. [DOI: 10.1002/ejlt.200600104] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Warschawski DE, Devaux PF. Order parameters of unsaturated phospholipids in membranes and the effect of cholesterol: a 1H-13C solid-state NMR study at natural abundance. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2005; 34:987-96. [PMID: 15952018 DOI: 10.1007/s00249-005-0482-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Accepted: 03/14/2005] [Indexed: 10/25/2022]
Abstract
Most biological phospholipids contain at least one unsaturated alkyl chain. However, few order parameters of unsaturated lipids have been determined because of the difficulty associated with isotopic labeling of a double bond. Dipolar recoupling on axis with scaling and shape preservation (DROSS) is a solid-state nuclear magnetic resonance technique optimized for measuring (1)H-(13)C dipolar couplings and order parameters in lipid membranes in the fluid phase. It has been used to determine the order profile of 1,2-dimyristoyl-sn-glycero-3-phosphocholine hydrated membranes. Here, we show an application for the measurement of local order parameters in multilamellar vesicles containing unsaturated lipids. Taking advantage of the very good (13)C chemical shift dispersion, one can easily follow the segmental order along the acyl chains and, particularly, around the double bonds where we have been able to determine the previously misassigned order parameters of each acyl chain of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). We have followed the variation of such order profiles with temperature, unsaturation content and cholesterol addition. We have found that the phase formed by DOPC with 30% cholesterol is analogous to the liquid-ordered (l(o)) phase. Because these experiments do not require isotopic enrichment, this technique can, in principle, be applied to natural lipids and biomembranes.
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Affiliation(s)
- Dror E Warschawski
- UMR 7099, CNRS, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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27
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Affiliation(s)
- M Schlame
- Department of Anesthesiology, Hospital for Special Surgery, Cornell University Medical College, 555 E. 70th St., New York, NY 10021, USA
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28
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Mancini A, Del Rosso F, Roberti R, Orvietani P, Coletti L, Binaglia L. Purification of ethanolaminephosphotransferase from bovine liver microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1437:80-92. [PMID: 9931448 DOI: 10.1016/s1388-1981(98)00011-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
CDP-ethanolamine:diacylglycerol ethanolaminephosphotransferase (EC 2. 7.8.1) has been purified to electrophoretic homogeneity and in a catalytically active form from bovine liver microsomes. The purification method is based on the high hydrophobicity of the protein whose charged sites appear to be masked from the interaction with the chromatographic stationary phases when membranes are solubilized with an excess of non-ionic detergent. The isolated protein has a molecular mass of about 38 kDa, as estimated by SDS-PAGE mobility, and exhibits both ethanolaminephosphotransferase and cholinephosphotransferase activities. Evidence is given that both activities are Mn2+-dependent and that the same catalytic site is involved in cholinephosphotransferase and ethanolaminephosphotransferase reactions. Mg2+-dependent CDP-choline:diacylglycerol cholinephosphotransferase (EC 2.7.8.2) is completely inactivated during the solubilization and purification steps.
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Affiliation(s)
- A Mancini
- Institute of Biochemistry and Medical Chemistry, University of Perugia, Via del Giochetto, 3, 06122, Perugia, Italy
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Schlame M, Brody S, Hostetler KY. Mitochondrial cardiolipin in diverse eukaryotes. Comparison of biosynthetic reactions and molecular acyl species. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 212:727-35. [PMID: 8385010 DOI: 10.1111/j.1432-1033.1993.tb17711.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cardiolipin, a unique dimeric phospholipid of bacteria and mitochondria, can be synthesized by two alternative pathways discovered in rat and Escherichia coli, respectively. In mitochondrial preparations from fungi (Saccharomyces cerevisiae, Neurospora crassa), higher plants (Phaseolus aureus), molluscs (Mytilus edulis) and mammals (rat liver, bovine adrenal gland), cardiolipin was synthesized from CDP-diacylglycerol and phosphatidylglycerol, suggesting a common eukaryotic mechanism of cardiolipin formation which is in contrast to the prokaryotic biosynthesis from two molecules of phosphatidylglycerol. All mitochondrial cardiolipin synthases were inhibited by lysophosphatidylglycerol, were insensitive to N-ethylmaleimide and required divalent cations, although they had different cation specificities. The molecular species of cardiolipin from rat liver, bovine heart, S. cerevisiae and N. crassa were analysed by high-performance liquid chromatography of the derivative 1,3-bis[3'-sn-phosphatidyl]-2-benzoyl-sn-glycerol dimethyl ester. Cardiolipins from these organisms contained mainly monounsaturated or diunsaturated chains with 16 or 18 carbon atoms, resulting in a relatively homogeneous distribution of double bonds and carbon numbers among the four acyl positions. About half of the molecular species were symmetrical, i.e. they combined two identical diacylglycerol moieties. In N. crassa, the same species pattern was found at growth temperatures of 25 degrees C and 37 degrees C. Tentative molecular models were created for the most abundant molecular species and subjected to energy minimization. Geometric data, derived from these models, suggested similarities in the gross structure of the major cardiolipin species from different sources.
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Affiliation(s)
- M Schlame
- Department of Medicine, University of California San Diego
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30
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Mancini A, Roberti R, Binaglia L, el Missiri A, Freysz L. Factors affecting the stability of detergent-solubilized cholinephosphotransferase and ethanolaminephosphotransferase. MEMBRANE BIOCHEMISTRY 1993; 10:43-52. [PMID: 8389973 DOI: 10.3109/09687689309150251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cholinephosphotransferase (CPT) and ethanolaminephosphotransferase (EPT) are the enzymes catalyzing the last step of the de novo pathway for phosphatidylcholine and phosphatidylethanolamine synthesis, respectively. A major limitation for the complete characterization of the reactions catalyzed by the two enzymes derives from their poor stability in detergent-containing buffers. CPT is heavily inactivated, when native membranes are solubilized using a series of detergents, whereas EPT activity is better preserved during solubilization. An investigation of the factors which could play a role in preserving both enzymes from inactivation was carried out. The dramatic loss of enzymatic activities occurring upon dilution of solubilized membranes with detergent-containing buffers can be reduced by supplementing the dilution medium with phospholipids. The addition of Mn2+ ions to the dispersion buffer increases the stability of both enzymes. The procedure previously described for solubilizing EPT from rat brain microsomes has been modified on the basis of this evidence. Microsomes were solubilized in buffered detergent solutions containing Mn2+ ions and both CPT and EPT were partially purified in their active form by anion-exchange chromatography.
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Affiliation(s)
- A Mancini
- Institute of Biochemistry, Medical School, University of Perugia, Italy
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31
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Roberti R, Mancini A, Freysz L, Binaglia L. Reversibility of the reactions catalyzed by cholinephosphotransferase and ethanolaminephosphotransferase solubilized from rat-brain microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1165:183-8. [PMID: 1333282 DOI: 10.1016/0005-2760(92)90185-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The incorporation of CMP into CDP-ethanolamine and CDP-choline, catalyzed by ethanolaminephosphotransferase (EC 2.7.8.1) and cholinephosphotransferase (EC 2.7.8.2), respectively, has been studied in solubilized preparations of rat-brain microsomes. Mn2+ ions were required for the maximal activity of both enzymes. The CMP concentration needed to reach the half-maximal reaction rate was 1.6 microM for both activities. The rate of incorporation of CMP into CDP-choline and CDP-ethanolamine was increased by increasing the concentration of phosphatidylcholine and phosphatidylethanolamine, respectively, in detergent-phospholipid micellar systems. The rate of the reaction at pH 6.5 was comparable with that measured at pH 8.5, whereas the rate of synthesis of phosphatidylcholine and phosphatidylethanolamine, catalyzed by the same enzymes, increased with pH. Ethanolaminephosphotransferase, which catalyzes the synthesis of phosphatidylethanolamine from CDP-ethanolamine and diacylglycerol, was co-eluted with the enzyme activity catalyzing the reverse reaction, when solubilized microsomes were submitted to anion exchange chromatography on DEAE Bio-Gel A. Cholinephosphotransferase was inactivated during the chromatographic procedure.
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Affiliation(s)
- R Roberti
- Department of Biochemistry, Faculty of Medicine, University of Perugia, Italy
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32
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Shamovsky IL, Yarovskaya IY. Comparison of global-minimum-energy conformations of phospholipids. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0166-1280(91)80024-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Darnell JC, Saltiel AR. Coenzyme A-dependent, ATP-independent acylation of 2-acyl lysophosphatidylinositol in rat liver microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1084:292-9. [PMID: 1888777 DOI: 10.1016/0005-2760(91)90071-o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Phosphatidylinositol (PI) is synthesized from cytidine-diphosphodiacylglycerol (CDP-DAG) and inositol by the enzyme PI synthase. CDP-DAG is itself synthesized from phosphatidic acid and CTP. The observation that PI differs in fatty acid composition from its precursors CDP-DAG and phosphatidic acid led to the proposal that following its synthesis the fatty acids of PI are removed and replaced by others in a process called fatty acid remodelling. Previously, we used rat liver microsomes to study the molecular mechanisms of PI remodelling. Following its synthesis, PI is rapidly deacylated to form lysoPI which is reacylated to form new PI species. PI remodelling occurs predominantly at the 1-position. We demonstrate here that lysoPI can be acylated in the 1-position in an ATP-independent manner. The acylation of 2-acyl lysoPI by the coenzyme A-dependent, ATP-independent mechanism was examined. The acylation exhibits a pH optimum of 7.5, does not require a divalent cation, and is not inhibited by Ca2+ or Mg2+, although Zn2+ is a potent inhibitor. The apparent Km values for coenzyme A and 2-acyl lysoPI are 14 microM and 30 microM, respectively. The acylation of 2-acyl lysoPI incorporates primarily stearic acid into the 1-position of PI, as would be expected based on the fatty acid composition of steady-state PI in rat hepatocytes.
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Affiliation(s)
- J C Darnell
- Laboratory of Molecular Oncology, Rockefeller University, New York
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34
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Schlame M, Beyer K, Hayer-Hartl M, Klingenberg M. Molecular species of cardiolipin in relation to other mitochondrial phospholipids. Is there an acyl specificity of the interaction between cardiolipin and the ADP/ATP carrier? EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 199:459-66. [PMID: 1649052 DOI: 10.1111/j.1432-1033.1991.tb16144.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Molecular species in the three major mitochondrial lipids cardiolipin, phosphatidylcholine and phosphatidylethanolamine were analysed in bovine heart and Saccharomyces cerevisiae. In both organisms cardiolipin contains mainly diacylglycerol moieties with two unsaturated chains and a significant higher proportion of C18-C18 species than phosphatidylcholine and phosphatidylethanolamine. To study whether the specific acyl composition of cardiolipin has a functional significance in lipid-protein interaction, experiments were made with the isolated ADP/ATP carrier of bovine heart mitochondria since this dimeric protein is known to be tightly associated with six molecules of cardiolipin [Beyer, K. and Klingenberg, M. (1985) Biochemistry 24, 3821-3826]. This association seems to be very strong as protein-bound cardiolipin does not exchange with soluble cardiolipin on a time scale of hours. Analysis of the species composition suggests that one carriers dimer is associated with four molecules of tetralinoleoyl cardiolipin and two molecules of trilinoleoyl-monolinolenoyl cardiolipin. Catalytic hydrogenation of the acyl chains of carrier-bound cardiolipin does not result in release of cardiolipin as judged by 31P-NMR spectroscopy. The ADP/ATP carrier was reconstituted with saturated phosphatidylcholines and spin-labelled cardiolipin whose double bonds were subsequently saturated by catalytic hydrogenation. ESR spectroscopy shows that saturation of spin-labelled cardiolipin has no significant impact on its association with the ADP/ATP carrier. However, precipitation of the detergent-solubilized ADP/ATP carrier can only be induced by addition of unsaturated but not by saturated cardiolipin. It is concluded that the specific acyl composition of cardiolipin is not a prerequisite of its high affinity for the ADP/ATP carrier, at least when the protein is reconstituted in a saturated phosphatidylcholine environment.
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Affiliation(s)
- M Schlame
- Institute of Physical Biochemistry, University of Munich, Federal Republic of Germany
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Lee TC, Malone B, Buell AB, Blank ML. Occurrence of ether-containing inositol phospholipids in bovine erythrocytes. Biochem Biophys Res Commun 1991; 175:673-8. [PMID: 1826838 DOI: 10.1016/0006-291x(91)91618-m] [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: 12/28/2022]
Abstract
Several proteins including bovine erythrocyte acetylcholinesterase are anchored in the membrane through glycoinositol phospholipids containing an alkyl linkage at the sn-1 position of the glycerol. However, the existence of 1-alkyl-2-acyl-sn-glycero-3-phosphoinositol (alkylacyl-GPI) in biological systems has not been demonstrated. In this study, we identified the presence of alkylacyl-GPI in bovine erythrocytes by the following criteria: (1) TLC-Rf value, (2) radyllyso-GPI was produced after phospholipase A2 treatment of the diradyl-GPI, and (3) benzoate derivatives of alkylacylglycerols produced by phospholipase C hydrolysis of diradyl-GPI had the same retention time as that of authentic alkylacylglycerobenzoates on normal-phase HPLC. Diradyl-GPI consisted of 5-10% alkylacyl-GPI. Reverse-phase HPLC analysis of alkylacylglycerobenzoates derived from bovine erythrocyte alkylacyl-GPI showed a multiplicity of species with 18:0-20:4 (11.7%), 16:0-18:1 + 18:0-18:2 (34.9%), and 18:0-18:1 (19.4%) being the major components. Composition of alkyl chains of alkylacyl-GPI from bovine erythrocytes was similar to the reported value for alkylacylglycerols isolated from the glycoinositol phospholipid anchor of bovine erythrocyte acetylcholinesterase. Based on these results, we suggest that alkylacyl-GPI serves as a precursor for the glycoinositol phospholipid of the anchored proteins.
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Affiliation(s)
- T C Lee
- Medical Sciences Division, Oak Ridge Associated Universities, Tennessee 37831
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36
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Wolff RL, Entressangles B. Compositional changes of fatty acids in the 1(1")-and 2(2")-positions of cardiolipin from liver, heart, and kidney mitochondria of rats fed a low-fat diet. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1082:136-42. [PMID: 2007177 DOI: 10.1016/0005-2760(91)90187-m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cardiolipins from liver, heart and kidney mitochondria of rats fed a fat-free diet for 66 days have been analyzed for their fatty acid composition and positional distribution. The main effect was a dramatic decrease of linoleic acid which was counterbalanced by increases in the levels of palmitoleic, oleic and cis-vaccenic acids. Linoleic acid remains asymmetrically distributed between positions 1(1") and 2(2") with a positive selectivity for positions 1(1"). Its decrease is considerably faster in positions 2(2") than in positions 1(1"), which would suggest different rates of fatty acid turnover. Fat deficiency induces the appearance of 18:2(n-7) and a significant increase of 20:3(n-6) (dihomo-gamma-linolenic acid) in liver and kidney cardiolipins. In contrast, 20:3(n-6) level remains unchanged in other mitochondrial phospholipids. 18:2(n-7) and 20:3(n-6) are almost evenly distributed between both pairs of positions. Both acids have a common structural feature, that is double bonds in positions 8 and 11. 20:3(n-9) accumulates in large amounts in other mitochondrial phospholipids, but not in cardiolipins. Although surprising, 20:3(n-6) has thus to be considered as a specific marker of deficiency for cardiolipins when it is esterified to positions 1(1"). Taking into account various analytical data, it would appear that positions 1(1") of cardiolipins can only incorporate unsaturated fatty acids containing at least one cis double bond in position 8 or 9, with no other double bond between these positions and the carboxylic group.
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Affiliation(s)
- R L Wolff
- I.S.T.A.B.-I.T.E.R.G., Laboratoire de Lipochimie Alimentaire, Université de Bordeaux I, Talence, France
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Schlame M, Rüstow B. Lysocardiolipin formation and reacylation in isolated rat liver mitochondria. Biochem J 1990; 272:589-95. [PMID: 2268287 PMCID: PMC1149749 DOI: 10.1042/bj2720589] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Liver mitochondrial cardiolipin (CL) is distinguished from other phospholipids by the presence of linoleoyl in almost all molecular species, and the biosynthesis of these species is not yet understood. The present study was carried out in order to test the hypothesis that the linoleoyl proportion of CL may be specifically enriched by a deacylation-reacylation cycle. Incorporation of [14C]glycerol 3-phosphate into the metabolites of the CL pathway was accompanied by formation of 14C-labelled monolyso- and dilyso-CL. Labelling of dilyso-CL was increased or decreased by stimulation or inhibition respectively of mitochondrial phospholipase A2. These data suggest a rapid deacylation of newly formed [14C]CL by phospholipase A2, whereas endogenous mitochondrial CL was very resistant to hydrolytic degradation. Unlike dilyso-CL, monolyso-CL could be reacylated by [14C]linoleoyl residues. [14C]Linoleoyl incorporation into CL was also observed when exogenous CL was added instead of monolyso-CL, thus indicating the concerted action of de- and re-acylation. Although 1-palmitoyl-2-[14C]linoleoyl-phosphatidylcholine was a suitable acyl donor under experimental conditions, the reaction was not a transacylation but required splitting of [14C]linoleic acid from phosphatidylcholine and formation of [14C]linoleoyl-CoA as an intermediate. The [14C]linoleoyl was mainly bound to the sn-2(2") position of CL, and a small portion (about 20%) to the sn-1(1") position. It is concluded that a cycle, comprising CL deacylation and monolyso-CL reacylation by linoleoyl-CoA, provides a potential mechanism for the remodelling of molecular species of newly formed CL.
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Affiliation(s)
- M Schlame
- Institute of Physical Biochemistry, University of Munich, Federal Republic of Germany
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38
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Bell MV, Dick JR. Molecular species composition of phosphatidylinositol from the brain, retina, liver and muscle of cod (Gadus morhua). Lipids 1990. [DOI: 10.1007/bf02544035] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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39
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Schlame M, Horvàth L, Vìgh L. Relationship between lipid saturation and lipid-protein interaction in liver mitochondria modified by catalytic hydrogenation with reference to cardiolipin molecular species. Biochem J 1990; 265:79-85. [PMID: 2154183 PMCID: PMC1136616 DOI: 10.1042/bj2650079] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lipid acyl double bonds in isolated mitochondrial membranes were gradually reduced by palladium-complex-catalysed hydrogenation, and the resulting saturation was monitored by fatty acid analysis of phosphatidylcholine, phosphatidylethanolamine and cardiolipin. The courses of hydrogenation of these phospholipids suggested that cardiolipin is in a membrane compartment which is less accessible to the applied catalyst. Native cardiolipin and its hydrogenation products were further characterized by analysis of their molecular diacylglycerol species. A decrease in the double bond content was accompanied by an increased amount of motionally restricted lipids at the hydrophobic interface of proteins as measured by two different spin-labelled lipids (C-14 positional isomers of spin-labelled stearic acid and phosphatidylcholine analogues). The protein-immobilized fraction of spin-labelled stearic acid increased in parallel with the hydrogenation of cardiolipin rather than of phosphatidylcholine or phosphatidylethanolamine. These data are interpreted in terms of a tight association of cardiolipin with membrane proteins, which becomes looser upon double bond reduction leading to the replacement of cardiolipin by spin-labelled stearic acid in the solvation shell. Thus the hydrophobic moiety of cardiolipin, characterized by double-unsaturated C18-C18 diacylglycerol species, seems to be an important structural requirement for the high protein affinity of this compound.
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Affiliation(s)
- M Schlame
- Institute of Biochemistry, Biological Research Center, Szeged, Hungary
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40
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Roberti R, Vecchini A, Freysz L, Masoom M, Binaglia L. An improved procedure for the purification of ethanolaminephosphotransferase. Reconstitution of the purified enzyme with lipids. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1004:80-8. [PMID: 2545264 DOI: 10.1016/0005-2760(89)90216-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ethanolaminephosphotransferase (CDPethanolamine:1,2-diacylglycerol ethanolaminephosphotransferase, EC 2.7.8.1) has been purified in active form from rat brain microsomes by a two-step chromatographic procedure. Enzyme preparations characterized by high specific activity and stability were obtained supplementing the solubilization and elution buffers, containing 1% Triton X-100, with 0.01% 2,6-di-tert-butyl-4-methylphenol. The specific activity of the purified enzyme was about 1200-times higher than that of the crude solubilized enzyme. The lipid dependence of ethanolaminephosphotransferase was studied both in the presence of Triton X-100 and in detergent-free enzyme preparations. The activity of the detergent-solubilized ethanolaminephosphotransferase was strongly modified by phospholipids. The kinetic behaviour of the enzyme was also dependent on the lipids contained in the aggregates obtained by removal of the detergent from detergent/lipid/protein suspensions. A regulatory role of phospholipids on the activity of the membrane-bound ethanolaminephosphotransferase is discussed.
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Affiliation(s)
- R Roberti
- Department of Biochemistry, Faculty of Medicine, University of Perugia, Italy
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41
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Vecchini A, Roberti R, Freysz L, Binaglia L. Partial purification of ethanolaminephosphotransferase from rat brain microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 918:40-7. [PMID: 3030437 DOI: 10.1016/0005-2760(87)90007-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rat brain ethanolaminephosphotransferase (CDPethanolamine : 1,2-diacylglycerol ethanolaminephosphotransferase, EC 2.7.8.1) was solubilized by treating rat brain microsomes with buffered solutions containing octyl glucoside or Triton X-100. The solubilized enzyme was stable both at 4 degrees C and at -18 degrees C. A partial purification was obtained using an ion-exchange chromatographic procedure. The partially purified enzyme showed four major bands in SDS-polyacrylamide gel electrophoresis; its specific activity was increased by a factor of 37 compared to that of the membrane-bound enzyme. Glycerol and diacylglycerol were effective as stabilizers. Phosphatidylcholine, lysophosphatidylcholine and phosphatidylserine increased both the specific activity and the stability of the partially purified enzyme.
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Schlame M, Rüstow B, Kunze D, Rabe H, Reichmann G. Phosphatidylglycerol of rat lung. Intracellular sites of formation de novo and acyl species pattern in mitochondria, microsomes and surfactant. Biochem J 1986; 240:247-52. [PMID: 3827844 PMCID: PMC1147400 DOI: 10.1042/bj2400247] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The subcellular site of phosphatidylglycerol (PG) formation for lung surfactant has not been convincingly clarified. To approach this problem we analysed the acyl species pattern of lung PG in mitochondria, microsomes and surfactant by h.p.l.c. separation of its 1,2-diacyl-3-naphthylurethane derivatives. Both mitochondrial and microsomal PG proved identical with surfactant PG, containing the major species 1-palmitoyl-2-oleoyl-PG and 1,2-dipalmitoyl-PG. The fatty acid composition of mitochondrial PG differs markedly from that of diphosphatidylglycerol. This may be taken as an indication that mitochondrial PG is synthesized on purpose to form surfactant, rather than being only the precursor of diphosphatidylglycerol. In vitro, sn-[U-14C]glycerol 3-phosphate incorporation into PG of mitochondria or microsomes occurs in the presence of CTP, ATP and CoA but independently of the supply of exogenous lipoidic precursors. Although the rate in vitro of autonomous PG synthesis, and the endogenous PG content, are higher in mitochondria than in microsomes, it is assumed that both subcellular fractions are involved in PG formation for surfactant.
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Chabbott H, Cabot MC. Phorbol diesters inhibit enzymatic hydrolysis of diacylglycerols in vitro. Proc Natl Acad Sci U S A 1986; 83:3126-30. [PMID: 3458169 PMCID: PMC323465 DOI: 10.1073/pnas.83.10.3126] [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: 01/05/2023] Open
Abstract
The effect of phorbol 12-myristate 13-acetate (PMA) on diacylglycerol lipase activity was examined in rat serum, tissue, and cellular preparations by using di[14C]oleoylglycerol, [3H]palmitoylacetylglycerol, and membrane-resident phospholipase C-generated diacylglycerols as substrates. These experiments were conducted to address whether phorbol esters can mimic diacylglycerols in interacting with enzymes other than protein kinase C. Serum hydrolysis of palmitoylacetylglycerol, assayed by the formation of [3H]palmitic acid, was inhibited by PMA, 4-O-methyl-PMA, or phorbol 12,13-dibutyrate (in order of decreasing potency). The hydrolysis of palmitoylacetylglycerol was inhibited more than 40% by the addition of PMA at a 1:1 molar ratio with substrate. The inhibition resembled the competitive type, with a Ki of approximately 2.7 microM. PMA in the 10-60 microM range also inhibited hydrolysis of palmitoylacetylglycerol by lipases from rat brain microsomes and by homogenates of C3H/10T1/2 mouse fibroblasts. PMA was likewise inhibitory when assayed in an intramembrane enzyme-substrate milieu in which diacylglycerols were generated, in situ, by treatment of [3H]palmitate-labeled cell homogenates with phospholipase C. Collectively, these data demonstrate that PMA, which is now thought to act by mimicry of diacylglycerols, can inhibit the action of diacylglycerol lipase. It is possible that such a mechanism is linked to the multiplicity of responses elicited by phorbol diesters and that other agents may function by means of enzyme interactions (post-phospholipase C) to influence the levels of the cellular diacylglycerol mediators.
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Wood R, Upreti GC, deAntueno RJ. A comparison of lipids from liver and hepatoma subcellular membranes. Lipids 1986; 21:292-300. [PMID: 3713448 DOI: 10.1007/bf02536416] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver and hepatoma 7288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity. Hepatoma NADH: cytochrome C reductase and 5'-nucleotidase exhibited abnormal subcellular distributions. The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by elevated percentages of diphosphatidylglycerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedly from liver and, unlike liver, did not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions, contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some acyl moieties for the biosynthesis of various hepatoma lipid classes differs from liver sources. The possible changes in acyl pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species that could contribute to the abnormal properties of the hepatoma membranes.
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Wolff RL, Combe NA, Entressangles B. Positional distribution of fatty acids in cardiolipin of mitochondria from 21-day-old rats. Lipids 1985; 20:908-14. [PMID: 4094521 DOI: 10.1007/bf02534776] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pure cardiolipins (1,3-diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21-day-old male Wistar rats and submitted to Naja naja venom phospholipase A2 (EC 3.1.1.4) action. Incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin (di [1 (1'') acyl sn-glycero-3-phosphoryl] 1',3'-sn-glycerol) and fatty acids from positions 2(2'') was obtained in less than two hr practically without side reactions. Cardiolipins from the three organs contained low levels of saturated fatty acids; stearic acid accounted for 0.4-0.7% and palmitic acid for 1.4-3.5% of total fatty acids. These percentages apparently depended on the organ. In all three cases, linoleic acid was the major component, but its percentage varied from 62-78% of total fatty acids. Acyl chains linked to positions 1 (1'') of all three cardiolipin preparations exhibited a similar pattern: they were composed of linoleic acid for 85-89%. This fatty acid also was the main component esterified at position 2 (2''), but its percentage was much more variable: from 39.8% in heart to 51.2% in kidney and 67.8% in liver mitochondria. The remaining acids comprised octadecenoic and polyunsaturated fatty acids with more than 18 carbon atoms in different proportions. As opposed to other phospholipids, cis-vaccenic acid, and not oleic acid, was the main octadecenoic acid present in cardiolipins. Octadecenoic acids were nine- to 10-fold more concentrated at positions 2 (2'') than at positions 1 (1''). The percentage of cis-vaccenic acid was four- to five-fold higher than that of oleic acid at positions 2 (2''), whereas oleic acid dominated at positions 1 (1'').(ABSTRACT TRUNCATED AT 250 WORDS)
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Malone B, Lee T, Snyder F. Inactivation of platelet activating factor by rabbit platelets. Lyso-platelet activating factor as a key intermediate with phosphatidylcholine as the source of arachidonic acid in its conversion to a tetraenoic acylated product. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)89625-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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47
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Lee T, Lenihan DJ, Malone B, Roddy LL, Wasserman SI. Increased biosynthesis of platelet-activating factor in activated human eosinophils. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)91044-6] [Citation(s) in RCA: 289] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Gabellec MM, Steffan AM, Dodeur M, Durand G, Kirn A, Rebel G. Membrane lipids of hepatocytes, Kupffer cells and endothelial cells. Biochem Biophys Res Commun 1983; 113:845-53. [PMID: 6870894 DOI: 10.1016/0006-291x(83)91076-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The membrane lipid composition of isolated hepatocytes, Kupffer cells and endothelial cells was determined. The hepatocytes are characterized by a lower quantity of gangliosides, cholesterol, sphingomyelin and a reduced cholesterol/phospholipid molar ratio when compared to the two other liver cell types. The main gangliosides of Kupffer and endothelial cells are the GM3 species, and those of hepatocytes are of the polysialogangliosides species.
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Mathur SN, Simon I, Lokesh BR, Spector AA. Phospholipid fatty acid modification of rat liver microsomes affects acylcoenzyme A:cholesterol acyltransferase activity. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 751:401-11. [PMID: 6303434 DOI: 10.1016/0005-2760(83)90299-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of phospholipid fatty acyl composition on the activity of acylcoenzyme A:cholesterol acyltransferase was investigated in rat liver microsomes. Specific phosphatidylcholine replacements were produced by incubating the microsomes with liposomes and bovine liver phospholipid-exchange protein. Although the fatty acid composition of the microsomes was modified appreciably, there was no change in the microsomal phospholipid or cholesterol content. As compared to microsomes enriched for 2 h with dioleoylphosphatidylcholine, those enriched with dipalmitoylphosphatidylcholine exhibited 30-45% less acyl-CoA:cholesterol acyltransferase activity. Enrichment with 1-palmitoyl-2-linoleoylphosphatidylcholine increased acyl-CoA:cholesterol acyltransferase activity by 20%. By contrast, dilinoleoylphosphatidylcholine abolished microsomal acyl-CoA:cholesterol acyltransferase activity almost completely. Addition of cofactors that stimulated microsomal lipid peroxidation inhibited acyl-CoA:cholesterol acyltransferase activity by only 10%, however, and did not increase the inhibition produced by submaximal amounts of dilinoleoylphosphatidylcholine. Certain of the phosphatidylcholine replacements produced changes in palmitoyl-CoA hydrolase, NADPH-dependent lipid peroxidase, glucose-6-phosphatase and UDPglucuronyl transferase activities, but they did not closely correlate with the alterations in acyl-CoA:cholesterol acyltransferase activity. Electron spin resonance measurements with the 5-nitroxystearate probe indicated that microsomal lipid ordering was reduced to a roughly similar extent by dioleoyl- or by dilinoleoylphosphatidylcholine enrichment. Since these enrichments produce widely different effects on acyl-CoA:cholesterol acyltransferase activity, changes in bulk membrane lipid fluidity cannot be the only factor responsible for phospholipid fatty acid compositional effect on acyl-CoA:cholesterol acyltransferase. The present results are more consistent with a modulation resulting from either changes in the lipid microenvironment of acyl-CoA:cholesterol acyltransferase or a direct interaction between specific phosphatidylcholine fatty acyl groups and acyl-CoA:cholesterol acyltransferase.
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50
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Molecular species of phosphatidylcholine, -ethanolamine, -serine, and -inositol in microsomal and photoreceptor membranes of bovine retina. J Lipid Res 1983. [DOI: 10.1016/s0022-2275(20)37967-0] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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