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Yang L, Jiang Y, Sun A, Chen M, Li Q, Wang P, Zhang J. Mechanism of two styryl BODIPYs as fluorescent probes and protective agents in lipid bilayers against aqueous ClO . RSC Adv 2024; 14:28957-28964. [PMID: 39263435 PMCID: PMC11389514 DOI: 10.1039/d4ra03433c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 08/18/2024] [Indexed: 09/13/2024] Open
Abstract
Two styryl BODIPY derivatives, BOH and BOE, with different hydrophilic properties, were investigated for their reaction mechanisms in lipid bilayers against aqueous ClO-, by both experimental and theoretical methods. Density functional theory (DFT) calculations confirmed their identical conformations in solution. Fluorescence spectra and high-resolution mass spectra corroborated the central vinyl group as a common antioxidation moiety against ClO- oxidation. In giant unilamellar vesicles (GUVs), distinct reaction kinetics with ClO- suggested that BOE provided superior protective effects compared to BOH on lipids. Molecular dynamics simulations indicated that the lipophilic octyloxy group in BOE led to its deeper localization within the lipid phase, bringing it closer to the corresponding lipid target group. This study establishes the two styryl BODIPYs as promising fluorescent probes for detecting aqueous ClO- in lipid-water polyphasic systems.
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Affiliation(s)
- Lu Yang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Yanglin Jiang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Ailin Sun
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Mingqing Chen
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Qiwei Li
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Peng Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
| | - Jianping Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, School of Chemistry and Life Resources, Renmin University of China Beijing 100872 China +86 10 62516604
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Kalyana Sundaram RV, Chatterjee A, Bera M, Grushin K, Panda A, Li F, Coleman J, Lee S, Ramakrishnan S, Ernst AM, Gupta K, Rothman JE, Krishnakumar SS. Roles for diacylglycerol in synaptic vesicle priming and release revealed by complete reconstitution of core protein machinery. Proc Natl Acad Sci U S A 2023; 120:e2309516120. [PMID: 37590407 PMCID: PMC10450444 DOI: 10.1073/pnas.2309516120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/14/2023] [Indexed: 08/19/2023] Open
Abstract
Here, we introduce the full functional reconstitution of genetically validated core protein machinery (SNAREs, Munc13, Munc18, Synaptotagmin, and Complexin) for synaptic vesicle priming and release in a geometry that enables detailed characterization of the fate of docked vesicles both before and after release is triggered with Ca2+. Using this setup, we identify new roles for diacylglycerol (DAG) in regulating vesicle priming and Ca2+-triggered release involving the SNARE assembly chaperone Munc13. We find that low concentrations of DAG profoundly accelerate the rate of Ca2+-dependent release, and high concentrations reduce clamping and permit extensive spontaneous release. As expected, DAG also increases the number of docked, release-ready vesicles. Dynamic single-molecule imaging of Complexin binding to release-ready vesicles directly establishes that DAG accelerates the rate of SNAREpin assembly mediated by chaperones, Munc13 and Munc18. The selective effects of physiologically validated mutations confirmed that the Munc18-Syntaxin-VAMP2 "template" complex is a functional intermediate in the production of primed, release-ready vesicles, which requires the coordinated action of Munc13 and Munc18.
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Affiliation(s)
- R. Venkat Kalyana Sundaram
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Atrouli Chatterjee
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Manindra Bera
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Kirill Grushin
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Aniruddha Panda
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Feng Li
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Jeff Coleman
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Seong Lee
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Sathish Ramakrishnan
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Pathology, Yale University School of Medicine, New Haven, CT06520
| | - Andreas M. Ernst
- School of Biological Sciences, University of California San Diego, San Diego, CA92093
| | - Kallol Gupta
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - James E. Rothman
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Shyam S. Krishnakumar
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT06520
- Department of Neurology, Yale University School of Medicine, New Haven, CT06520
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Sundaram RVK, Chatterjee A, Bera M, Grushin K, Panda A, Li F, Coleman J, Lee S, Ramakrishnan S, Ernst AM, Gupta K, Rothman JE, Krishnakumar SS. Novel Roles for Diacylglycerol in Synaptic Vesicle Priming and Release Revealed by Complete Reconstitution of Core Protein Machinery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543781. [PMID: 37333317 PMCID: PMC10274626 DOI: 10.1101/2023.06.05.543781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Here we introduce the full functional reconstitution of genetically-validated core protein machinery (SNAREs, Munc13, Munc18, Synaptotagmin, Complexin) for synaptic vesicle priming and release in a geometry that enables detailed characterization of the fate of docked vesicles both before and after release is triggered with Ca 2+ . Using this novel setup, we discover new roles for diacylglycerol (DAG) in regulating vesicle priming and Ca 2+- triggered release involving the SNARE assembly chaperone Munc13. We find that low concentrations of DAG profoundly accelerate the rate of Ca 2+ -dependent release, and high concentrations reduce clamping and permit extensive spontaneous release. As expected, DAG also increases the number of ready-release vesicles. Dynamic single-molecule imaging of Complexin binding to ready-release vesicles directly establishes that DAG accelerates the rate of SNAREpin assembly mediated by Munc13 and Munc18 chaperones. The selective effects of physiologically validated mutations confirmed that the Munc18-Syntaxin-VAMP2 'template' complex is a functional intermediate in the production of primed, ready-release vesicles, which requires the coordinated action of Munc13 and Munc18. SIGNIFICANCE STATEMENT Munc13 and Munc18 are SNARE-associated chaperones that act as "priming" factors, facilitating the formation of a pool of docked, release-ready vesicles and regulating Ca 2+ -evoked neurotransmitter release. Although important insights into Munc18/Munc13 function have been gained, how they assemble and operate together remains enigmatic. To address this, we developed a novel biochemically-defined fusion assay which enabled us to investigate the cooperative action of Munc13 and Munc18 in molecular terms. We find that Munc18 nucleates the SNARE complex, while Munc13 promotes and accelerates the SNARE assembly in a DAG-dependent manner. The concerted action of Munc13 and Munc18 stages the SNARE assembly process to ensure efficient 'clamping' and formation of stably docked vesicles, which can be triggered to fuse rapidly (∼10 msec) upon Ca 2+ influx.
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Affiliation(s)
- R Venkat Kalyana Sundaram
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Atrouli Chatterjee
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Manindra Bera
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kirill Grushin
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Aniruddha Panda
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Feng Li
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jeff Coleman
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Seong Lee
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sathish Ramakrishnan
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Andreas M. Ernst
- School of Biological Sciences, University of California San Diego, La Jolla CA 92093, USA
| | - Kallol Gupta
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - James E. Rothman
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Shyam S. Krishnakumar
- Nanobiology Institute, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06520, USA
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Li D, Yang SG, He CW, Zhang ZT, Liang Y, Li H, Zhu J, Su X, Gong Q, Xie Z. Excess diacylglycerol at the endoplasmic reticulum disrupts endomembrane homeostasis and autophagy. BMC Biol 2020; 18:107. [PMID: 32859196 PMCID: PMC7453538 DOI: 10.1186/s12915-020-00837-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/24/2020] [Indexed: 01/22/2023] Open
Abstract
Background When stressed, eukaryotic cells produce triacylglycerol (TAG) to store nutrients and mobilize autophagy to combat internal damage. We and others previously reported that in yeast, elimination of TAG synthesizing enzymes inhibits autophagy under nitrogen starvation, yet the underlying mechanism has remained elusive. Results Here, we show that disruption of TAG synthesis led to diacylglycerol (DAG) accumulation and its relocation from the vacuolar membrane to the endoplasmic reticulum (ER). We further show that, beyond autophagy, ER-accumulated DAG caused severe defects in the endomembrane system, including disturbing the balance of ER-Golgi protein trafficking, manifesting in bulging of ER and loss of the Golgi apparatus. Genetic or chemical manipulations that increase consumption or decrease supply of DAG reversed these defects. In contrast, increased amounts of precursors of glycerolipid synthesis, including phosphatidic acid and free fatty acids, did not replicate the effects of excess DAG. We also provide evidence that the observed endomembrane defects do not rely on Golgi-produced DAG, Pkc1 signaling, or the unfolded protein response. Conclusions This work identifies DAG as the critical lipid molecule responsible for autophagy inhibition under condition of defective TAG synthesis and demonstrates the disruption of ER and Golgi function by excess DAG as the potential cause of the autophagy defect.
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Affiliation(s)
- Dan Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Shu-Gao Yang
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Cheng-Wen He
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Zheng-Tan Zhang
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Yongheng Liang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Hui Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Jing Zhu
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Xiong Su
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China.
| | - Qingqiu Gong
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
| | - Zhiping Xie
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
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5
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Zhou YM, Liu XC, Li YQ, Wang P, Han RM, Zhang JP, Skibsted LH. Synergy between plant phenols and carotenoids in stabilizing lipid-bilayer membranes of giant unilamellar vesicles against oxidative destruction. SOFT MATTER 2020; 16:1792-1800. [PMID: 31970380 DOI: 10.1039/c9sm01415b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have investigated the synergism between plant phenols and carotenoids in protecting the phosphatidylcholine (PC) membranes of giant unilamellar vesicles (GUVs) from oxidative destruction, for which chlorophyll-a (Chl-a) was used as a lipophilic photosensitizer. The effect was examined for seven different combinations of β-carotene (β-CAR) and plant phenols. The light-induced change in GUV morphology was monitored via conventional optical microscopy, and quantified by a dimensionless image-entropy parameter, ΔE. The ΔE-t time evolution profiles exhibiting successive lag phase, budding phase and ending phase could be accounted for by a Boltzmann model function. The length of the lag phase (LP in s) for the combination of syringic acid and β-CAR was more than seven fold longer than for β-CAR alone, and those for other different combinations followed the order: salicylic acid < vanillic acid < syringic acid > rutin > caffeic acid > quercetin > catechin, indicating that moderately reducing phenols appeared to be the most efficient membrane co-stabilizers. The same order held for the residual contents of β-CAR in membranes after light-induced oxidative degradation as determined by resonance Raman spectroscopy. The dependence of LP on the reducing power of phenols coincided with the Marcus theory plot for the rate of electron transfer from phenols to the radical cation β-CAR˙+ as a primary oxidative product, suggesting that the plant phenol regeneration of β-CAR plays an important role in stabilizing the GUV membranes, as further supported by the involvement of CAR˙+ and the distinct shortening of its lifetime as shown by transient absorption spectroscopy.
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Affiliation(s)
- Yi-Ming Zhou
- Department of Chemistry, Renmin University of China, Beijing, 100872, China.
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6
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Sawada D, Hirono A, Asakura K, Banno T. pH-Tolerant giant vesicles composed of cationic lipids with imine linkages and oleic acids. RSC Adv 2020; 10:34247-34253. [PMID: 35519057 PMCID: PMC9056790 DOI: 10.1039/d0ra06822e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/08/2020] [Indexed: 02/05/2023] Open
Abstract
Giant vesicles (GVs) have attracted attention as functional materials because they can encapsulate both hydrophilic and hydrophobic compounds. For next generation functional GVs, both tolerance and stimuli-sensitivity are needed. So far, vesicles tolerant to acidic or basic conditions were generated using a mixture of cationic lipids and fatty acids. Here, to create functional GVs that are tolerant to a wide pH range but sensitively respond at below a specific pH, the behaviour of GVs composed of a cationic lipid with an imine bond and oleic acid was investigated. Even though the GVs prepared by the film swelling method were tolerant to strongly acidic conditions, GVs without oleic acid gradually shrank, accompanied by the generation of oil droplets at the same pH. 1H NMR analysis revealed that during hydration of the film, the imine bond hydrolysed to provide a cationic surfactant and an oil component in the presence of oleic acid due to its own Lewis basicity, suggesting the dissociation of oleic acid. The results of fluorescence spectroscopy using an environment-responsive probe and IR spectroscopy indicated that the GV tolerance originated from the intermolecular interactions of cationic lipids and anionic oleate. Giant vesicles composed of cationic lipids having an imine linkage and oleic acid were stable at strong acidic conditions.![]()
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Affiliation(s)
- Daichi Sawada
- Department of Applied Chemistry
- Faculty of Science and Technology
- Keio University
- Yokohama 223-8522
- Japan
| | - Ayana Hirono
- Department of Applied Chemistry
- Faculty of Science and Technology
- Keio University
- Yokohama 223-8522
- Japan
| | - Kouichi Asakura
- Department of Applied Chemistry
- Faculty of Science and Technology
- Keio University
- Yokohama 223-8522
- Japan
| | - Taisuke Banno
- Department of Applied Chemistry
- Faculty of Science and Technology
- Keio University
- Yokohama 223-8522
- Japan
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7
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Local accumulation of diacylglycerol alters membrane properties nonlinearly due to its transbilayer activity. Commun Chem 2019. [DOI: 10.1038/s42004-019-0175-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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8
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Quartino PY, Fidelio GD, Manneville JB, Goud B, Ambroggio EE. Detecting phospholipase activity with the amphipathic lipid packing sensor motif of ArfGAP1. Biochem Biophys Res Commun 2018; 505:290-294. [DOI: 10.1016/j.bbrc.2018.09.116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 09/18/2018] [Indexed: 11/25/2022]
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Nakagawa KM, Noguchi H. Bilayer sheet protrusions and budding from bilayer membranes induced by hydrolysis and condensation reactions. SOFT MATTER 2018; 14:1397-1407. [PMID: 29383371 DOI: 10.1039/c7sm02326j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Shape transformations of flat bilayer membranes and vesicles induced by hydrolysis and condensation reactions of amphiphilic molecules are studied using coarse-grained molecular dynamics simulations. The hydrolysis and condensation reactions result in the formation and dissociation of amphiphilic molecules, respectively. Asymmetric reactions between the inner and outer leaflets of a vesicle can transport amphiphilic molecules between the leaflets. It is found that the resulting area difference between the two leaflets induces bilayer sheet protrusion (BP) and budding at low reduced volumes of the vesicles, whereas BP only occurs at high reduced volumes. The probabilities of these two types of transformations depend on the shear viscosity of the surrounding fluids compared to the membrane as well as the reaction rates. A higher surrounding fluid viscosity leads to more BP formation. The inhomogeneous spatial distribution of the hydrophobic reaction products forms the nuclei of BP formation, and faster diffusion of the products enhances BP formation. Our results suggest that adjustment of the viscosity is important to control membrane shape transformations in experiments.
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Affiliation(s)
- Koh M Nakagawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
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11
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Ahyayauch H, Sot J, Collado MI, Huarte N, Requejo-Isidro J, Alonso A, Goñi FM. End-product diacylglycerol enhances the activity of PI-PLC through changes in membrane domain structure. Biophys J 2016; 108:1672-1682. [PMID: 25863059 DOI: 10.1016/j.bpj.2015.02.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/28/2015] [Accepted: 02/12/2015] [Indexed: 11/25/2022] Open
Abstract
Diacylglycerol (DAG)-induced activation of phosphatidylinositol-phospholipase C (PI-PLC) was studied with vesicles containing PI, either pure or in mixtures with dimyristoyl phosphatidylcholine, distearoyl phosphatidylcholine, sphingomyelin, or galactosylceramide, used as substrates. At 22°C, DAG at 33 mol % increased PI-PLC activity in all of the mixtures, but not in pure PI bilayers. DAG also caused an overall decrease in diphenylhexatriene fluorescence polarization (decreased molecular order) in all samples, and increased overall enzyme binding. Confocal fluorescence microscopy of giant unilamellar vesicles of all of the compositions under study, with or without DAG, and quantitative evaluation of the phase behavior using Laurdan generalized polarization, and of enzyme binding to the various domains, indicated that DAG activates PI-PLC whenever it can generate fluid domains to which the enzyme can bind with high affinity. In the specific case of PI/dimyristoyl phosphatidylcholine bilayers at 22°C, DAG induced/increased enzyme binding and activation, but no microscopic domain separation was observed. The presence of DAG-generated nanodomains, or of DAG-induced lipid packing defects, is proposed instead for this system. In PI/galactosylceramide mixtures, DAG may exert its activation role through the generation of small vesicles, which PI-PLC is known to degrade at higher rates. In general, our results indicate that global measurements obtained using fluorescent probes in vesicle suspensions in a cuvette are not sufficient to elucidate DAG effects that take place at the domain level. The above data reinforce the idea that DAG functions as an important physical agent in regulating membrane and cell properties.
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Affiliation(s)
- Hasna Ahyayauch
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain; Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain; Institut Supérieur des Professions Infirmières et des Techniques de Santé, Rabat, Morocco
| | - Jesús Sot
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain
| | - M Isabel Collado
- SGiker, Servicios Generales de Investigación UPV/EHU, Bizkaia, Spain
| | - Nerea Huarte
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain; Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - José Requejo-Isidro
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain; Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - Alicia Alonso
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain; Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain
| | - Félix M Goñi
- Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Bilbao, Spain; Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
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Alwarawrah M, Hussain F, Huang J. Alteration of lipid membrane structure and dynamics by diacylglycerols with unsaturated chains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:253-63. [PMID: 26607007 DOI: 10.1016/j.bbamem.2015.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/05/2015] [Accepted: 11/18/2015] [Indexed: 01/15/2023]
Abstract
Diacylglycerols (DAGs) with unsaturated acyl chains play many important roles in biomembranes, such as a second messenger and activator for protein kinase C. In this study, three DAGs of distinctly different chain unsaturations (i.e. di16:0DAG (DPG), 16:0-18:1DAG (POG), and di18:1DAG (DOG)) are studied using atomistic MD simulation to compare their roles in the structure and dynamics of 16:0-18:1phosphatidylcholine (POPC) membranes. All three DAGs are able to produce the so-called 'condensing effect' in POPC membranes: decreasing area-per-lipid, and increasing acyl chain order and bilayer thickness. Our visual and quantitative analyses clearly show that DAG with unsaturated chains induce larger spacing between POPC headgroups, compared with DAG with saturated chains; this particular effect has long been hypothesized to be crucial for activating enzymes and receptors in cell membranes. DAGs with unsaturated chains are also located closer to the bilayer/aqueous interface than DPG and are more effective in slowing down lateral diffusion of molecules. We show that DAG molecules seek the "umbrella coverage" from neighboring phospholipid headgroups - similar to cholesterol. Unlike cholesterol, DAGs also hide their chains from water by laterally inserting their chains into the surrounding. Thus, acyl chains of DAG are more spread and disordered than those of PC due to the insertion. By calculating the potential of mean force (PMF) for POPC in POPC/DAG bilayers, we found that all three DAGs can significantly increase the free energy barrier for POPC to flip-flop, but only DAGs with unsaturated chains can additionally increase the free energy of POPC desorption.
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Affiliation(s)
- Mohammad Alwarawrah
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States
| | - Fazle Hussain
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Juyang Huang
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States.
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Jewell SA, Titball RW, Huyet J, Naylor CE, Basak AK, Gologan P, Winlove CP, Petrov PG. Clostridium perfringensα-toxin interaction with red cells and model membranes. SOFT MATTER 2015; 11:7748-7761. [PMID: 26303814 DOI: 10.1039/c5sm00876j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effects of Clostridium perfringensα-toxin on host cells have previously been studied extensively but the biophysical processes associated with toxicity are poorly understood. The work reported here shows that the initial interaction between the toxin and lipid membrane leads to measurable changes in the physical properties and morphology of the membrane. A Langmuir monolayer technique was used to assess the response of different lipid species to toxin. Sphingomyelin and unsaturated phosphatidylcholine showed the highest susceptibility to toxin lypolitic action, with a two stage response to the toxin (an initial, rapid hydrolysis stage followed by the insertion and/or reorganisation of material in the monolayer). Fluorescence confocal microscopy on unsaturated phosphatidylcholine vesicles shows that the toxin initially aggregates at discrete sites followed by the formation of localised "droplets" accumulating the hydrolysis products. This process is accompanied by local increases in the membrane dipole potential by about 50 (±42) mV. In contrast, red blood cells incubated with the toxin suffered a decrease of the membrane dipole potential by 50 (±40) mV in areas of high toxin activity (equivalent to a change in electric field strength of 10(7) V m(-1)) which is sufficient to affect the functioning of the cell membrane. Changes in erythrocyte morphology caused by the toxin are presented, and the early stages of interaction between toxin and membrane are characterised using thermal shape fluctuation analysis of red cells which revealed two distinct regimes of membrane-toxin interaction.
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Affiliation(s)
- S A Jewell
- School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK.
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14
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Ekman P, Maula T, Yamaguchi S, Yamamoto T, Nyholm TK, Katsumura S, Slotte J. Formation of an ordered phase by ceramides and diacylglycerols in a fluid phosphatidylcholine bilayer — Correlation with structure and hydrogen bonding capacity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2111-7. [DOI: 10.1016/j.bbamem.2015.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Revised: 06/18/2015] [Accepted: 06/19/2015] [Indexed: 12/21/2022]
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15
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Abstract
Since its discovery in the 19th century, phosphatidylcholine (PC) has been regarded primarily as a structural lipid. However, more recent evidence, much of it in the last five years, strongly suggests that PC has other roles. Here, we explore some of that new evidence and consider the possibility that the ultimate role of phosphatidylcholine may not be predictable.
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Affiliation(s)
- Samuel Furse
- a Membrane Biochemistry and Biophysics, University of Utrecht , Utrecht , The Netherlands
| | - Anton I P M de Kroon
- a Membrane Biochemistry and Biophysics, University of Utrecht , Utrecht , The Netherlands
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16
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Optical Microscopy of Giant Vesicles as a Tool to Reveal the Mechanism of Action of Antimicrobial Peptides and the Specific Case of Gomesin. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2015. [DOI: 10.1016/bs.adplan.2014.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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17
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Gardiner J, Marc J. Phospholipases may play multiple roles in anisotropic plant cell growth. PROTOPLASMA 2013; 250:391-5. [PMID: 22270827 DOI: 10.1007/s00709-012-0377-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 01/09/2012] [Indexed: 05/08/2023]
Abstract
Both the cortical microtubule cytoskeleton and cellulose microfibrils are important for the anisotropic growth of plant cells. Although the two systems interact, the details of this interaction are far from clear. It has been shown the inhibitors of phospholipase D, phospholipase A(2) and phospholipase C all cause disorganisation of the microtubule cytoskeleton. Since the phospholipases act on the plasma membrane, which links cortical microtubules to cellulose microfibrils in the cell wall, they may play a key role in the communication between the two structures. This communication may take various forms. Microtubule-linked phospholipase activity may cause the organisation of underlying cellulose microfibril liquid crystals. Alternatively, phospholipases may co-operate in the regulation of plasma membrane fluidity, affecting the movement of cellulose synthase complexes in the underlying plasma membrane. GPI-anchored proteins in the plasma membrane, which are cleaved by phospholipases, may possibly play a role.
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Affiliation(s)
- John Gardiner
- The School of Biological Sciences, University of Sydney, Camperdown 2006, Australia.
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18
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Varnier A, Kermarrec F, Blesneac I, Moreau C, Liguori L, Lenormand JL, Picollet-D’hahan N. A Simple Method for the Reconstitution of Membrane Proteins into Giant Unilamellar Vesicles. J Membr Biol 2010; 233:85-92. [DOI: 10.1007/s00232-010-9227-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 12/28/2009] [Indexed: 12/19/2022]
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19
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Gómez-Fernández JC, Corbalán-García S. Diacylglycerols, multivalent membrane modulators. Chem Phys Lipids 2007; 148:1-25. [PMID: 17560968 DOI: 10.1016/j.chemphyslip.2007.04.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Accepted: 04/04/2007] [Indexed: 12/30/2022]
Abstract
Diacylglycerols are second messengers confined to biomembranes and, although relatively simple molecules from the structural point of view, they are able of triggering a surprisingly wide range of biological responses. Diacylglycerols are recognized by a well conserved protein motif, such as the C1 domain. This domain was observed for the first time in protein kinases C but is now known to be present in many other proteins. The effect of diacylglycerols is not limited to binding to C1 domains and they are able to alter the biophysical properties of biomembranes and hence modulate the activity of membrane associated proteins and also facilitate some processes like membrane fusion.
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Affiliation(s)
- Juan C Gómez-Fernández
- Departamento de Bioquímica y Biología Molecular (A), Facultad de Veterinaria, Universidad de Murcia, Apartado de Correos 4021, Murcia, Spain.
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20
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Spassova MA, Hewavitharana T, Xu W, Soboloff J, Gill DL. A common mechanism underlies stretch activation and receptor activation of TRPC6 channels. Proc Natl Acad Sci U S A 2006; 103:16586-91. [PMID: 17056714 PMCID: PMC1637625 DOI: 10.1073/pnas.0606894103] [Citation(s) in RCA: 354] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The TRP family of ion channels transduce an extensive range of chemical and physical signals. TRPC6 is a receptor-activated nonselective cation channel expressed widely in vascular smooth muscle and other cell types. We report here that TRPC6 is also a sensor of mechanically and osmotically induced membrane stretch. Pressure-induced activation of TRPC6 was independent of phospholipase C. The stretch responses were blocked by the tarantula peptide, GsMTx-4, known to specifically inhibit mechanosensitive channels by modifying the external lipid-channel boundary. The GsMTx-4 peptide also blocked the activation of TRPC6 channels by either receptor-induced PLC activation or by direct application of diacylglycerol. The effects of the peptide on both stretch- and diacylglycerol-mediated TRPC6 activation indicate that the mechanical and chemical lipid sensing by the channel has a common molecular mechanism that may involve lateral-lipid tension. The mechanosensing properties of TRPC6 channels highly expressed in smooth muscle cells are likely to play a key role in regulating myogenic tone in vascular tissue.
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Affiliation(s)
- Maria A. Spassova
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
- *To whom correspondence may be addressed at:
Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 North Greene Street, Baltimore, MD 21201. E-mail:
or
| | - Thamara Hewavitharana
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Wen Xu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Jonathan Soboloff
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Donald L. Gill
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
- *To whom correspondence may be addressed at:
Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 North Greene Street, Baltimore, MD 21201. E-mail:
or
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21
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Dimova R, Aranda S, Bezlyepkina N, Nikolov V, Riske KA, Lipowsky R. A practical guide to giant vesicles. Probing the membrane nanoregime via optical microscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:S1151-S1176. [PMID: 21690835 DOI: 10.1088/0953-8984/18/28/s04] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Research on giant vesicles is becoming increasingly popular. Giant vesicles provide model biomembrane systems for systematic measurements of mechanical and rheological properties of bilayers as a function of membrane composition and temperature, as well as hydrodynamic interactions. Membrane response to external factors (for example electric fields, ions and amphiphilic molecules) can be directly visualized under the microscope. In this paper we review our current understanding of lipid bilayers as obtained from studies on giant unilamellar vesicles. Because research on giant vesicles increasingly attracts the interest of scientists from various backgrounds, we also try to provide a concise introduction for newcomers in the field. Finally, we summarize some recent developments on curvature effects induced by polymers, domain formation in membranes and shape transitions induced by electric fields.
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22
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Park SH, Oh SG, Mun JY, Han SS. Loading of gold nanoparticles inside the DPPC bilayers of liposome and their effects on membrane fluidities. Colloids Surf B Biointerfaces 2006; 48:112-8. [PMID: 16520025 DOI: 10.1016/j.colsurfb.2006.01.006] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 01/18/2006] [Accepted: 01/18/2006] [Indexed: 11/23/2022]
Abstract
Gold nanoparticles were loaded in the bilayer of dipalmitoylphosphatidylcholine (DPPC) liposomes, named as gold-loaded liposomes. Above the gel to liquid-crystalline phase transition temperature, membrane fluidities of DPPC liposomes were changed by loading the gold nanoparticles. Compared with liposomes without loading the gold nanoparticles, gold-loaded liposomes showed the lower fluorescence anisotropy values. That is, the membrane fluidities of DPPC bilayer were increased by loading the gold nanoparticles. The membrane fluidities were increased as the amount of gold nanoparticles increased. The existence of gold nanoparticles in the DPPC bilayer was observed by transmission electron microscopy. Through the energy dispersive X-ray spectrometer, the particles in DPPC bilayer were confirmed to be gold nanoparticles.
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Affiliation(s)
- Sung-Hee Park
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, South Korea
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23
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Taniguchi Y, Ohba T, Miyata H, Ohki K. Rapid phase change of lipid microdomains in giant vesicles induced by conversion of sphingomyelin to ceramide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:145-53. [PMID: 16580624 DOI: 10.1016/j.bbamem.2006.02.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 02/13/2006] [Accepted: 02/17/2006] [Indexed: 10/24/2022]
Abstract
To understand the role of sphingomyelinase (SMase) in the function of biological membranes, we have investigated the effect of conversion of sphingomyelin (SM) to ceramide (Cer) on the assembly of domains in giant unilamellar vesicles (GUVs). The GUVs were prepared from mixture of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), N-palmitoly-D-erythro-sphingosine (C16Cer), N-palmitoyl-D-erythro-sphingosylphosphorylcholine (C16SM) and cholesterol. The amounts of DOPC, sum of C16Cer and C16SM, and cholesterol were kept constant (the ratio of these four lipids is shown as 1:X:1-X:1 (molar ratio), i.e., X is C16Cer/(C16Cer+C16SM)). Shape and distribution of domains formed in the GUVs were monitored by a fluorescent lipid, Texas Red 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (0.1 mol%). In GUVs containing low C16Cer (X=0 and 0.25), round-shaped domains labeled by the fluorescent lipid were present, suggesting coexistence of liquid-ordered and disordered domains. In GUVs containing intermediate Cer concentration (X=0.5), the fluorescent domain covered most of GUV surface, which was surrounded by gel-like domains. Differential scanning calorimetry of multilamellar vesicles prepared in the presence of higher Cer concentration (X>or=0.5) suggested existence of a Cer-enriched gel phase. Video microscopy showed that the enzymatic conversion of SM to Cer caused rapid change in the domain structure: several minutes after the SMase addition, the fluorescent region spread over the GUV surface, within which regions with darker contrast existed. Image-based measurement of generalized polarization (GP) of 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan), which is related to the acyl chain ordering of the lipids, was performed. Before the SMase treatment domains with high (0.65) and low (below 0.4) GP values coexisted, presumably reflecting the liquid-ordered and disordered domains; after the SMase treatment regions with intermediate GP values (0.5) and smaller regions with higher GP values (0.65) were present. Generation of Cer thus caused a phase transition from liquid-ordered and disordered phases to a gel and liquid phase.
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Affiliation(s)
- Yukinori Taniguchi
- Department of Physics, Graduate School of Science, Tohoku University, Aza-aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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24
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Pincet F, Tareste D, Amar MB, Perez E. Spontaneous and reversible switch from amphiphilic to oil-like structures. PHYSICAL REVIEW LETTERS 2005; 95:218101. [PMID: 16384186 DOI: 10.1103/physrevlett.95.218101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Indexed: 05/05/2023]
Abstract
Current theories assume that the amphiphilicity of biological membranes is always preserved. We observed that two hydrogen-bonding lipid layers in contact can spontaneously and reversibly lose their amphiphilic structure and turn into an assembly of oily complexes. This result opens a new angle for understanding the reorganization of lipids during membrane fusion, since similar complexes could fill the troubling hydrophobic voids displayed in the current models. The unique tribological properties described here may also find application in the development of novel nanolubricants.
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Affiliation(s)
- Frédéric Pincet
- Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR8550, Centre National de la Recherche Scientifique et Universités Paris 6 et 7, 24, rue Lhomond, 75231 Paris Cedex 05, France
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25
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Ahyayauch H, Villar AV, Alonso A, Goñi FM. Modulation of PI-specific phospholipase C by membrane curvature and molecular order. Biochemistry 2005; 44:11592-600. [PMID: 16114896 DOI: 10.1021/bi050715k] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus cereus has been assayed on large and small unilamellar vesicles consisting of PI, either pure or in mixtures with other lipids. Vesicle diameter (in the 50-300 nm range) influences PI-PLC activity, enzyme rates increasing with decreasing curvature radii. With sonicated unilamellar vesicles of pure PI, two apparent K(s) values are observed, one in the 0-2 mM concentration range and the other in the 2-12 mM concentration range. The latter ( approximately 4.2 mM) corresponds to previously published values, while the low-concentration K(s) is on the same order of magnitude as the single apparent K(m) value found with large unilamellar liposomes ( approximately 0.30 mM). PI-PLC appears to be very sensitive to bilayer composition. Certain nonsubstrate lipids, e.g., galactosylceramide or cholesterol, inhibit PI-PLC in a dose-dependent way, at least up to 33 mol % in the bilayers, under conditions with a constant PI concentration. Simultaneous measurements of enzyme activity, interfacial enzyme binding, and fluorescence of different probes, on a variety of bilayer compositions, reveal that both the level of enzyme binding and activity decrease with increasing lipid order, as measured by the fluorescence polarization of the hydrophobic probe diphenylhexatriene. In contrast, no correlation is found for enzyme activity with fluorescence changes of probes, e.g., laurdan, that report on phenomena occurring mainly at the lipid-water interface. Sphingomyelin has a dual effect. Up to 40 mol %, it increases PI-PLC activity, with little effect on bilayer molecular order. At higher proportions, the increased lipid chain order causes a decrease in enzyme activity. The same effects are observed for distearoylphosphatidylcholine when added to PI bilayers. These results support the "two-stage model" for binding of PI-PLC to lipid bilayers, and underline the significance of the enzyme partial penetration into the membrane hydrophobic matrix for its catalytic activity.
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Affiliation(s)
- Hasna Ahyayauch
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
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26
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Contreras FX, Basañez G, Alonso A, Herrmann A, Goñi FM. Asymmetric addition of ceramides but not dihydroceramides promotes transbilayer (flip-flop) lipid motion in membranes. Biophys J 2004; 88:348-59. [PMID: 15465865 PMCID: PMC1305011 DOI: 10.1529/biophysj.104.050690] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transbilayer lipid motion in membranes may be important in certain physiological events, such as ceramide signaling. In this study, the transbilayer redistribution of lipids induced either by ceramide addition or by enzymatic ceramide generation at one side of the membrane has been monitored using pyrene-labeled phospholipid analogs. When added in organic solution to preformed liposomes, egg ceramide induced transbilayer lipid motion in a dose-dependent way. Short-chain (C6 and C2) ceramides were less active than egg ceramide, whereas dihydroceramides or dioleoylglycerol were virtually inactive in promoting flip-flop. The same results (either positive or negative) were obtained when ceramides, dihydroceramides, or diacylglycerols were generated in situ through the action of a sphingomyelinase or of a phospholipase C. The phenomenon was dependent on the bilayer lipid composition, being faster in the presence of lipids that promote inverted phase formation, e.g., phosphatidylethanolamine and cholesterol; and, conversely, slower in the presence of lysophosphatidylcholine, which inhibits inverted phase formation. Transbilayer motion was almost undetectable in bilayers composed of pure phosphatidylcholine or pure sphingomyelin. The use of pyrene-phosphatidylserine allowed detection of flip-flop movement induced by egg ceramide in human red blood cell membranes at a rate comparable to that observed in model membranes. The data suggest that when one membrane leaflet becomes enriched in ceramides, they diffuse toward the other leaflet. This is counterbalanced by lipid movement in the opposite direction, so that net mass transfer between monolayers is avoided. These observations may be relevant to the physiological mechanism of transmembrane signaling via ceramides.
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Affiliation(s)
- F.-Xabier Contreras
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; and Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie/Biophysik, D-10115 Berlin, Germany
| | - Gorka Basañez
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; and Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie/Biophysik, D-10115 Berlin, Germany
| | - Alicia Alonso
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; and Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie/Biophysik, D-10115 Berlin, Germany
| | - Andreas Herrmann
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; and Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie/Biophysik, D-10115 Berlin, Germany
| | - Félix M. Goñi
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; and Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie/Biophysik, D-10115 Berlin, Germany
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