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Xia F, Wan JB. Chemical derivatization strategy for mass spectrometry-based lipidomics. MASS SPECTROMETRY REVIEWS 2023; 42:432-452. [PMID: 34486155 DOI: 10.1002/mas.21729] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/02/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Lipids, serving as the structural components of cellular membranes, energy storage, and signaling molecules, play the essential and multiple roles in biological functions of mammals. Mass spectrometry (MS) is widely accepted as the first choice for lipid analysis, offering good performance in sensitivity, accuracy, and structural characterization. However, the untargeted qualitative profiling and absolute quantitation of lipids are still challenged by great structural diversity and high structural similarity. In recent decade, chemical derivatization mainly targeting carboxyl group and carbon-carbon double bond of lipids have been developed for lipidomic analysis with diverse advantages: (i) offering more characteristic structural information; (ii) improving the analytical performance, including chromatographic separation and MS sensitivity; (iii) providing one-to-one chemical isotope labeling internal standards based on the isotope derivatization regent in quantitative analysis. Moreover, the chemical derivatization strategy has shown great potential in combination with ion mobility mass spectrometry and ambient mass spectrometry. Herein, we summarized the current states and advances in chemical derivatization-assisted MS techniques for lipidomic analysis, and their strengths and challenges are also given. In summary, the chemical derivatization-based lipidomic approach has become a promising and reliable technique for the analysis of lipidome in complex biological samples.
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Affiliation(s)
- Fangbo Xia
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, China
| | - Jian-Bo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, China
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2
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Bahja J, Dymond MK. Does membrane curvature elastic energy play a role in mediating oxidative stress in lipid membranes? Free Radic Biol Med 2021; 171:191-202. [PMID: 34000382 DOI: 10.1016/j.freeradbiomed.2021.05.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023]
Abstract
The effects of oxidative stress on cells are associated with a wide range of pathologies. Oxidative stress is predominantly initiated by the action of reactive oxygen species and/or lipoxygenases on polyunsaturated fatty acid containing lipids. The downstream products are oxidised phospholipids, bioactive aldehydes and a range of Schiff base by-products between aldehydes and lipids, or other biomacromolecules. In this review we assess the impact of oxidative stress on lipid membranes, focusing on the changes that occur to the curvature preference (lipid spontaneous curvature) and elastic properties of membranes, since these biophysical properties modulate phospholipid homeostasis. Studies show that the lipid products of oxidative stress reduce stored curvature elastic energy in membranes. Based upon this observation, we hypothesize that the effects of oxidative stress on lipid membranes will be reduced by compounds that increase stored curvature elastic energy. We find a strong correlation appears across literature studies that we have reviewed, such that many compounds like vitamin E, Curcumin, Coenzyme Q10 and vitamin A show behaviour consistent with this hypothesis. Finally, we consider whether age-related changes in lipid composition represent the homeostatic response of cells to compensate for the accumulation of in vivo lipid oxidation products.
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Affiliation(s)
- Julia Bahja
- Centre for Stress and Age-Related Disease, University of Brighton, Lewes Rd, Brighton, BN2 4GL, UK
| | - Marcus K Dymond
- Centre for Stress and Age-Related Disease, University of Brighton, Lewes Rd, Brighton, BN2 4GL, UK.
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3
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Dymond MK. Lipid monolayer spontaneous curvatures: A collection of published values. Chem Phys Lipids 2021; 239:105117. [PMID: 34265278 DOI: 10.1016/j.chemphyslip.2021.105117] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 11/24/2022]
Abstract
Lipid monolayer spontaneous curvatures (or lipid intrinsic curvatures) are one of several material properties of lipids that enable the stored curvature elastic energy in a lipid aggregate to be determined. Stored curvature elastic energy is important since it can modulate the function of membrane proteins and plays a role in the regulatory pathways of phospholipid homeostasis. Due to the large number of different lipid molecules that might theoretically exist in nature, very few lipid spontaneous curvatures have been determined. Herein the values of lipid spontaneous curvatures that exist in the literature are collected, alongside key experimental details. Where possible, trends in the data are discussed and finally, obvious gaps in the knowledge are signposted.
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Affiliation(s)
- Marcus K Dymond
- Chemistry Research and Enterprise Group, School of Pharmacy and Biomolecular Sciences, Huxley Building, University of Brighton, BN2 4GL, United Kingdom.
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4
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GlnK Facilitates the Dynamic Regulation of Bacterial Nitrogen Assimilation. Biophys J 2017; 112:2219-2230. [PMID: 28538158 PMCID: PMC5448240 DOI: 10.1016/j.bpj.2017.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 04/10/2017] [Accepted: 04/14/2017] [Indexed: 11/29/2022] Open
Abstract
Ammonium assimilation in Escherichia coli is regulated by two paralogous proteins (GlnB and GlnK), which orchestrate interactions with regulators of gene expression, transport proteins, and metabolic pathways. Yet how they conjointly modulate the activity of glutamine synthetase, the key enzyme for nitrogen assimilation, is poorly understood. We combine experiments and theory to study the dynamic roles of GlnB and GlnK during nitrogen starvation and upshift. We measure time-resolved in vivo concentrations of metabolites, total and posttranslationally modified proteins, and develop a concise biochemical model of GlnB and GlnK that incorporates competition for active and allosteric sites, as well as functional sequestration of GlnK. The model predicts the responses of glutamine synthetase, GlnB, and GlnK under time-varying external ammonium level in the wild-type and two genetic knock-outs. Our results show that GlnK is tightly regulated under nitrogen-rich conditions, yet it is expressed during ammonium run-out and starvation. This suggests a role for GlnK as a buffer of nitrogen shock after starvation, and provides a further functional link between nitrogen and carbon metabolisms.
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Hague CV, Postle AD, Attard GS, Dymond MK. Cell cycle dependent changes in membrane stored curvature elastic energy: evidence from lipidomic studies. Faraday Discuss 2013; 161:481-97; discussion 563-89. [PMID: 23805754 DOI: 10.1039/c2fd20078c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One of the most developed theories of phospholipid homeostasis is the intrinsic curvature hypothesis, which, in broad terms, postulates that cells regulate their lipid composition so as to keep constant the membrane stored curvature elastic energy. The implication of this hypothesis is that lipid composition is determined by a ratio control function consisting of the weighted sum of concentrations of type II lipids in the numerator and the weighted sum of concentrations of Type 0 lipids in the denominator. In previous work we used a data-driven approach, based on lipidomic data from asynchronous cell cultures, to determine a criterion that allows the different lipid species to be assigned to the set of type 0 or of type II lipids, and hence construct a ratio control function that serves as a proxy for the lipid contribution to total membrane stored curvature elastic energy in vivo. Here we apply the curvature elastic energy proxy to the analysis of lipid composition data from synchronous HeLa cells as they traverse the cell cycle. Our analysis suggests HeLa cells modify their membrane stored elastic energy through the cell cycle. In S-phase type 0 lipids are the most abundant, whilst in G2 type II lipids are most abundant. Changes in our proxy for membrane stored elastic energy correlate with membrane curvature dependent processes in the HeLa cell around division, providing some insights into the interplay between the individual lipid and protein contributions to membrane free energy.
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Affiliation(s)
- Charlotte V Hague
- Faculty of Natural and Environmental Sciences, University of Southampton, UK
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6
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Furse S, Liddell S, Ortori CA, Williams H, Neylon DC, Scott DJ, Barrett DA, Gray DA. The lipidome and proteome of oil bodies from Helianthus annuus (common sunflower). J Chem Biol 2013; 6:63-76. [PMID: 23532185 PMCID: PMC3606697 DOI: 10.1007/s12154-012-0090-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 12/28/2012] [Indexed: 12/02/2022] Open
Abstract
In this paper we report the molecular profiling, lipidome and proteome, of the plant organelle known as an oil body (OB). The OB is remarkable in that it is able to perform its biological role (storage of triglycerides) whilst resisting the physical stresses caused by changes during desiccation (dehydration) and germination (rehydration). The molecular profile that confers such extraordinary physical stability on OBs was determined using a combination of 31P/1H nuclear magnetic resonance (NMR), high-resolution mass spectrometry and nominal mass-tandem mass spectrometry for the lipidome, and gel-electrophoresis-chromatography-tandem mass spectrometry for the proteome. The integrity of the procedure for isolating OBs was supported by physical evidence from small-angle neutron-scattering experiments. Suppression of lipase activity was crucial in determining the lipidome. There is conclusive evidence that the latter is dominated by phosphatidylcholine (∼60 %) and phosphatidylinositol (∼20 %), with a variety of other head groups (∼20 %). The fatty acid profile of the surface monolayer comprised palmitic, linoleic and oleic acids (2:1:0.25, 1H NMR) with only traces of other fatty acids (C24:0, C22:0, C18:0, C18:3, C16:2; by MS). The proteome is rich in oleosins (78 %) with the remainder being made up of caleosins and steroleosins. These data are sufficiently detailed to inform an update of the understood model of this organelle and can be used to inform the use of such components in a range of molecular biological, biotechnological and food industry applications. The techniques used in this study for profiling the lipidome throw a new light on the lipid profile of plant cellular compartments.
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Affiliation(s)
- Samuel Furse
- School of Biosciences, University of Nottingham, College Lane, Sutton Bonington, Nottinghamshire, LE12 5RD UK
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7
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Jouhet J. Importance of the hexagonal lipid phase in biological membrane organization. FRONTIERS IN PLANT SCIENCE 2013; 4:494. [PMID: 24348497 PMCID: PMC3848315 DOI: 10.3389/fpls.2013.00494] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/18/2013] [Indexed: 05/20/2023]
Abstract
Domains are present in every natural membrane. They are characterized by a distinctive protein and/or lipid composition. Their size is highly variable from the nano- to the micrometer scale. The domains confer specific properties to the membrane leading to original structure and function. The determinants leading to domain organization are therefore important but remain obscure. This review presents how the ability of lipids to organize into hexagonal II or lamellar phases can promote particular local structures within membranes. Since biological membranes are composed of a mixture of lipids, each with distinctive biophysical properties, lateral and transversal sorting of lipids can promote creation of domains inside the membrane through local modulation of the lipid phase. Lipid biophysical properties have been characterized for long based on in vitro analyses using non-natural lipid molecules; their re-examinations using natural lipids might open interesting perspectives on membrane architecture occurring in vivo in various cellular and physiological contexts.
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Affiliation(s)
- Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, CNRSGrenoble, France
- Laboratoire de Physiologie Cellulaire et Végétale, Univ. Grenoble AlpesGrenoble, France
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherches en Technologies et Sciences pour le Vivant, Direction des Sciences du Vivant, Commissariat à l'Energie Atomique et aux Energies AlternativesGrenoble, France
- Laboratoire de Physiologie Cellulaire et Végétale, USC1359, Institut National de la Recherche AgronomiqueGrenoble, France
- *Correspondence: Juliette Jouhet, Laboratoire de Physiologie Cellulaire et Végétale (LPCV), CNRS (UMR5168) / Univ. Grenoble Alpes / INRA (USC1359) / CEA Grenoble, Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), 17 rue des Martyrs, 38054 Grenoble Cedex 9, France e-mail:
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8
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Dymond MK, Hague CV, Postle AD, Attard GS. An in vivo ratio control mechanism for phospholipid homeostasis: evidence from lipidomic studies. J R Soc Interface 2012; 10:20120854. [PMID: 23256189 DOI: 10.1098/rsif.2012.0854] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While it is widely accepted that the lipid composition of eukaryotic membranes is under homeostatic control, the mechanisms through which cells sense lipid composition are still the subject of debate. It has been postulated that membrane curvature elastic energy is the membrane property that is regulated by cells, and that lipid composition is maintained by a ratio control function derived from the concentrations of type II and type 0 lipids, weighted appropriately. We assess this proposal by seeking a signature of ratio control in quantified lipid composition data obtained by electrospray ionization mass spectrometry from over 40 independent asynchronous cell populations. Our approach revealed the existence of a universal 'pivot' lipid, which marks the boundary between type 0 lipids and type II lipids, and which is invariant between different cell types or cells grown under different conditions. The presence of such a pivot species is a distinctive signature of the operation in vivo, in human cell lines, of a control function that is consistent with the hypothesis that membrane elastic energy is homeostatically controlled.
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Affiliation(s)
- Marcus K Dymond
- Division of Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton SO17 1BJ, UK.
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9
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Charalambous K, Booth PJ, Woscholski R, Seddon JM, Templer RH, Law RV, Barter LMC, Ces O. Engineering de novo membrane-mediated protein-protein communication networks. J Am Chem Soc 2012; 134:5746-9. [PMID: 22428921 DOI: 10.1021/ja300523q] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Mechanical properties of biological membranes are known to regulate membrane protein function. Despite this, current models of protein communication typically feature only direct protein-protein or protein-small molecule interactions. Here we show for the first time that, by harnessing nanoscale mechanical energy within biological membranes, it is possible to promote controlled communication between proteins. By coupling lipid-protein modules and matching their response to the mechanical properties of the membrane, we have shown that the action of phospholipase A(2) on acyl-based phospholipids triggers the opening of the mechanosensitive channel, MscL, by generating membrane asymmetry. Our findings confirm that the global physical properties of biological membranes can act as information pathways between proteins, a novel mechanism of membrane-mediated protein-protein communication that has important implications for (i) the underlying structure of signaling pathways, (ii) our understanding of in vivo communication networks, and (iii) the generation of building blocks for artificial protein networks.
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Affiliation(s)
- Kalypso Charalambous
- Institute of Chemical Biology and Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
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10
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Hermansson M, Hokynar K, Somerharju P. Mechanisms of glycerophospholipid homeostasis in mammalian cells. Prog Lipid Res 2011; 50:240-57. [DOI: 10.1016/j.plipres.2011.02.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 02/21/2011] [Accepted: 02/25/2011] [Indexed: 01/09/2023]
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11
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Liou JW, Gu MH, Chen YK, Chen WY, Chen YC, Tseng YH, Hung YJ, Chang HH. Visible light responsive photocatalyst induces progressive and apical-terminus preferential damages on Escherichia coli surfaces. PLoS One 2011; 6:e19982. [PMID: 21589873 PMCID: PMC3093399 DOI: 10.1371/journal.pone.0019982] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 04/22/2011] [Indexed: 01/10/2023] Open
Abstract
Background Recent research shows that visible-light responsive photocatalysts have potential usage in antimicrobial applications. However, the dynamic changes in the damage to photocatalyzed bacteria remain unclear. Methodology/Principal Findings Facilitated by atomic force microscopy, this study analyzes the visible-light driven photocatalyst-mediated damage of Escherichia coli. Results show that antibacterial properties are associated with the appearance of hole-like structures on the bacteria surfaces. Unexpectedly, these hole-like structures were preferentially induced at the apical terminus of rod shaped E. coli cells. Differentiating the damages into various levels and analyzing the percentage of damage to the cells showed that photocatalysis was likely to elicit sequential damages in E. coli cells. The process began with changing the surface properties on bacterial cells, as indicated in surface roughness measurements using atomic force microscopy, and holes then formed at the apical terminus of the cells. The holes were then subsequently enlarged until the cells were totally transformed into a flattened shape. Parallel experiments indicated that photocatalysis-induced bacterial protein leakage is associated with the progression of hole-like damages, further suggesting pore formation. Control experiments using ultraviolet light responsive titanium-dioxide substrates also obtained similar observations, suggesting that this is a general phenomenon of E. coli in response to photocatalysis. Conclusion/Significance The photocatalysis-mediated localization-preferential damage to E. coli cells reveals the weak points of the bacteria. This might facilitate the investigation of antibacterial mechanism of the photocatalysis.
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Affiliation(s)
- Je-Wen Liou
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Nanotechnology Research Center, National Dong-Hwa University, Hualien, Taiwan, Republic of China
| | - Ming-Hui Gu
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yen-Kai Chen
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Wen-Yi Chen
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yi-Cheng Chen
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yao-Hsuan Tseng
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, Republic of China
| | - Yu-Jiun Hung
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Hsin-Hou Chang
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Nanotechnology Research Center, National Dong-Hwa University, Hualien, Taiwan, Republic of China
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan, Republic of China
- * E-mail:
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12
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Ge C, Georgiev A, Öhman A, Wieslander Å, Kelly AA. Tryptophan residues promote membrane association for a plant lipid glycosyltransferase involved in phosphate stress. J Biol Chem 2010; 286:6669-84. [PMID: 21156807 DOI: 10.1074/jbc.m110.138495] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chloroplast membranes contain a substantial excess of the nonbilayer-prone monogalactosyldiacylglycerol (GalDAG) over the biosynthetically consecutive, bilayer-forming digalactosyldiacylglycerol (GalGalDAG), yielding a high membrane curvature stress. During phosphate shortage, plants replace phospholipids with GalGalDAG to rescue phosphate while maintaining membrane homeostasis. Here we investigate how the activity of the corresponding glycosyltransferase (GT) in Arabidopsis thaliana (atDGD2) depends on local bilayer properties by analyzing structural and activity features of recombinant protein. Fold recognition and sequence analyses revealed a two-domain GT-B monotopic structure, present in other plant and bacterial glycolipid GTs, such as the major chloroplast GalGalDAG GT atDGD1. Modeling led to the identification of catalytically important residues in the active site of atDGD2 by site-directed mutagenesis. The DGD synthases share unique bilayer interface segments containing conserved tryptophan residues that are crucial for activity and for membrane association. More detailed localization studies and liposome binding analyses indicate differentiated anchor and substrate-binding functions for these separated enzyme interface regions. Anionic phospholipids, but not curvature-increasing nonbilayer lipids, strongly stimulate enzyme activity. From our studies, we propose a model for bilayer "control" of enzyme activity, where two tryptophan segments act as interface anchor points to keep the substrate region close to the membrane surface. Binding of the acceptor substrate is achieved by interaction of positive charges in a surface cluster of lysines, arginines, and histidines with the surrounding anionic phospholipids. The diminishing phospholipid fraction during phosphate shortage stress will then set the new GalGalDAG/phospholipid balance by decreasing stimulation of atDGD2.
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Affiliation(s)
- Changrong Ge
- Center for Biomembrane Research, Stockholm University SE-10691 Stockholm, Sweden
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13
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Implication of sphingomyelin/ceramide molar ratio on the biological activity of sphingomyelinase. Biophys J 2010; 99:499-506. [PMID: 20643068 DOI: 10.1016/j.bpj.2010.04.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 04/12/2010] [Accepted: 04/15/2010] [Indexed: 12/11/2022] Open
Abstract
Sphingolipid signaling plays an important, yet not fully understood, role in diverse aspects of cellular life. Sphingomyelinase is a major enzyme in these signaling pathways, catalyzing hydrolysis of sphingomyelin to ceramide and phosphocholine. To address the related membrane dynamical structural changes and their feedback to enzyme activity, we have studied the effect of enzymatically generated ceramide in situ on the properties of a well-defined lipid model system. We found a gel-phase formation that was about four times faster than ceramide generation due to ceramide-sphingomyelin pairing. The gel-phase formation slowed down when the ceramide molar ratios exceeded those of sphingomyelin and stopped just at the solubility limit of ceramide, due to unfavorable pairwise interactions of ceramide with itself and with monounsaturated phosphatidylcholine. A remarkable correlation to in vitro experiments suggests a regulation of sphingomyelinase activity based on the sphingomyelin/ceramide molar ratio.
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Niemelä PS, Castillo S, Sysi-Aho M, Orešič M. Bioinformatics and computational methods for lipidomics. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:2855-62. [DOI: 10.1016/j.jchromb.2009.01.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 01/08/2009] [Accepted: 01/09/2009] [Indexed: 10/21/2022]
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15
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16
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Wikström M, Kelly AA, Georgiev A, Eriksson HM, Klement MR, Bogdanov M, Dowhan W, Wieslander A. Lipid-engineered Escherichia coli membranes reveal critical lipid headgroup size for protein function. J Biol Chem 2009; 284:954-65. [PMID: 18981182 PMCID: PMC2613627 DOI: 10.1074/jbc.m804482200] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 10/23/2008] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli membranes have a substantial bilayer curvature stress due to a large fraction of the nonbilayer-prone lipid phosphatidylethanolamine, and a mutant (AD93) lacking this lipid is severely crippled in several membrane-associated processes. Introduction of four lipid glycosyltransferases from Acholeplasma laidlawii and Arabidopsis thaliana, synthesizing large amounts of two nonbilayer-prone, and two bilayer-forming gluco- and galacto-lipids, (i) restored the curvature stress with the two nonbilayer lipids, and (ii) diluted the high negative lipid surface charge in all AD93 bilayers. Surprisingly, the bilayer-forming diglucosyl-diacylglycerol was almost as good in improving AD93 membrane processes as the two nonbilayer-prone glucosyl-diacylglycerol and galactosyl-diacylglycerol lipids, strongly suggesting that lipid surface charge dilution by these neutral lipids is very important for E. coli. Increased acyl chain length and unsaturation, plus cardiolipin (nonbilayer-prone) content, were probably also beneficial in the modified strains. However, despite a correct transmembrane topology for the transporter LacY in the diglucosyl-diacylglycerol clone, active transport failed in the absence of a nonbilayer-prone glycolipid. The corresponding digalactosyl-diacylglycerol bilayer lipid did not restore AD93 membrane processes, despite analogous acyl chain and cardiolipin contents. Chain ordering, probed by bis-pyrene lipids, was substantially lower in the digalactosyl-diacylglycerol strain lipids due to its extended headgroup. Hence, a low surface charge density of anionic lipids is important in E. coli membranes, but is inefficient if the headgroup of the diluting lipid is too large. This strongly indicates that a certain magnitude of the curvature stress is crucial for the bilayer in vivo.
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Affiliation(s)
- Malin Wikström
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm 10691, Sweden
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17
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Powl AM, East JM, Lee AG. Importance of Direct Interactions with Lipids for the Function of the Mechanosensitive Channel MscL. Biochemistry 2008; 47:12175-84. [DOI: 10.1021/bi801352a] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew M. Powl
- School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
| | - J. Malcolm East
- School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
| | - Anthony G. Lee
- School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
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18
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Alley SH, Ces O, Barahona M, Templer RH. X-ray diffraction measurement of the monolayer spontaneous curvature of dioleoylphosphatidylglycerol. Chem Phys Lipids 2008; 154:64-7. [PMID: 18405663 DOI: 10.1016/j.chemphyslip.2008.03.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 03/05/2008] [Accepted: 03/12/2008] [Indexed: 11/17/2022]
Abstract
Phosphatidylglycerol (PG) is an anionic lipid commonly found in large proportions in the cell membranes of bacteria and plants and, to a lesser extent, in animal cells. PG plays an important role in the regulation and determination of the elastic properties of the membrane. Using small angle X-ray scattering experiments, we obtain that the monolayer spontaneous curvature of dioleoylphosphatidylglycerol (DOPG) is -1/150+/-0.021 nm(-1) when measured in 150 mM NaCl. When the experiments are carried out in 150 mM NaCl and 20mM MgCl(2), the value obtained for the monolayer spontaneous curvature is -1/8.7+/-0.037 nm(-1). These values are of importance in modelling the effects of curvature elastic stress in membrane lipid homeostasis in the bacterium Acholeplasma laidlawii [Alley, S.H., Barahona, M., Ces, O., Templer, R.H., in press. Biophysical regulation of lipid biosynthesis in the plasma membrane. Biophys. J.] and indicate that divalent cations can play a significant role in altering curvature elastic stress.
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Affiliation(s)
- Stephen H Alley
- Department of Bioengineering, Imperial College London, United Kingdom
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