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Oliveira AC, Filipe HAL, Geraldes CF, Voth GA, Moreno MJ, Loura LMS. Interaction of MRI Contrast Agent [Gd(DOTA)] - with Lipid Membranes: A Molecular Dynamics Study. Inorg Chem 2024; 63:10897-10914. [PMID: 38795015 PMCID: PMC11186012 DOI: 10.1021/acs.inorgchem.4c00972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/16/2024] [Accepted: 04/30/2024] [Indexed: 05/27/2024]
Abstract
Contrast agents are important imaging probes in clinical MRI, allowing the identification of anatomic changes that otherwise would not be possible. Intensive research on the development of new contrast agents is being made to image specific pathological markers or sense local biochemical changes. The most widely used MRI contrast agents are based on gadolinium(III) complexes. Due to their very high charge density, they have low permeability through tight biological barriers such as the blood-brain barrier, hampering their application in the diagnosis of neurological disorders. In this study, we explore the interaction between the widely used contrast agent [Gd(DOTA)]- (Dotarem) and POPC lipid bilayers by means of molecular dynamics simulations. This metal complex is a standard reference where several chemical modifications have been introduced to improve key properties such as bioavailability and targeting. The simulations unveil detailed insights into the agent's interaction with the lipid bilayer, offering perspectives beyond experimental methods. Various properties, including the impact on global and local bilayer properties, were analyzed. As expected, the results indicate a low partition coefficient (KP) and high permeation barrier for this reference compound. Nevertheless, favorable interactions are established with the membrane leading to moderately long residence times. While coordination of one inner-sphere water molecule is maintained for the membrane-associated chelate, the physical-chemical attributes of [Gd(DOTA)]- as a MRI contrast agent are affected. Namely, increases in the rotational correlation times and in the residence time of the inner-sphere water are observed, with the former expected to significantly increase the water proton relaxivity. This work establishes a reference framework for the use of simulations to guide the rational design of new contrast agents with improved relaxivity and bioavailability and for the development of liposome-based formulations for use as imaging probes or theranostic agents.
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Affiliation(s)
- Alexandre C. Oliveira
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Hugo A. L. Filipe
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- CPIRN-IPG—Center
of Potential and Innovation of Natural Resources, Polytechnic Institute of Guarda, 6300-559 Guarda, Portugal
| | - Carlos F.G.C. Geraldes
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-393 Coimbra, Portugal
- CIBIT/ICNAS
- Instituto de Ciências Nucleares Aplicadas à Saúde, Pólo das Ciências
da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
| | - Gregory A. Voth
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, James Franck
Institute, and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637, United States
| | - Maria João Moreno
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CNC−Center
for Neuroscience and Cell Biology, University
of Coimbra, 3004-517 Coimbra, Portugal
| | - Luís M. S. Loura
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Faculty
of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
- CNC−Center
for Neuroscience and Cell Biology, University
of Coimbra, 3004-517 Coimbra, Portugal
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Soto-Arriaza M, Cena Ahumada E, Bonardd S, Melendez J. Calcein release from DPPC liposomes by phospholipase A2 activity: Effect of cholesterol and amphipathic copolymers. J Liposome Res 2024:1-13. [PMID: 38850012 DOI: 10.1080/08982104.2024.2361610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/25/2024] [Indexed: 06/09/2024]
Abstract
In this study, we evaluated the impact of incorporating diblock and triblock amphiphilic copolymers, as well as cholesterol into DPPC liposomes on the release of a model molecule, calcein, mediated by exogenous phospholipase A2 activity. Our findings show that calcein release slows down in the presence of copolymers at low concentration, while at high concentration, the calcein release profile resembles that of the DPPC control. Additionally, calcein release mediated by exogenous PLA2 decreases as the amount of solubilized cholesterol increases, with a maximum between 18 mol% and 20 mol%. At concentrations higher than 24 mol%, no calcein release was observed. Studies conducted on HEK-293 and HeLa cells revealed that DPPC liposomes reduced viability by only 5% and 12%, respectively, after 3 hours of incubation, while DPPC liposome in presence of 33 mol% of Cholesterol reduced viability by approximately 11% and 23%, respectively, during the same incubation period. For formulations containing copolymers at low and high concentrations, cell viability decreased by approximately 20% and 40%, respectively, after 3 hours of incubation. Based on these preliminary results, we can conclude that the presence of amphiphilic copolymers at low concentration can be used in the design of new DPPC liposomes, and together with cholesterol, they can modulate liposome stabilization. The new formulations showed low cytotoxicity in HEK-293 cells, and it was observed that calcein release depended entirely on PLA2 activity and the presence of calcium ions.
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Affiliation(s)
- Marco Soto-Arriaza
- Escuela de Química y Farmacia, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Eduardo Cena Ahumada
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastián Bonardd
- Centro de Física de Materiales (CSIC, UPV/EHU)-Materials Physics Center (MPC), Donostia-San Sebastían, Spain
- Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, University of the Basque Country UPV/EHU, Donostia-San Sebastian, Spain
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Chatterjee H, Mahapatra AJ, Zacharias M, Sengupta N. Helical reorganization in the context of membrane protein folding: Insights from simulations with bacteriorhodopsin (BR) fragments. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184333. [PMID: 38740122 DOI: 10.1016/j.bbamem.2024.184333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/20/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Membrane protein folding is distinct from folding of soluble proteins. Conformational acquisition in major membrane protein subclasses can be delineated into insertion and folding processes. An exception to the "two stage" folding, later developed to "three stage" folding, is observed within the last two helices in bacteriorhodopsin (BR), a system that serves as a model membrane protein. We employ a reductionist approach to understand interplay of molecular factors underlying the apparent defiance. Leveraging available solution NMR structures, we construct, sample in silico, and analyze partially (PIn) and fully inserted (FIn) BR membrane states. The membrane lateral C-terminal helix (CH) in PIn is markedly prone to transient structural distortions over microsecond timescales; a disorder prone region (DPR) is thereby identified. While clear transmembrane propensities are not acquired, the distortions induce alterations in local membrane curvature and area per lipid. Importantly, energetic decompositions reveal that overall, the N-terminal helix (NH) is thermodynamically more stable in the PIn. Higher overall stability of the FIn arises from favorable interactions between the NH and the CH. Our results establish lack of spontaneous transition of the PIn to the FIn, and attributes their partitioning to barriers that exceed those accessible with thermal fluctuations. This work paves the way for further detailed studies aimed at determining the thermo-kinetic roles of the initial five helices, or complementary external factors, in complete helical folding and insertion in BR. We comment that complementing such efforts with the growing field of machine learning assisted energy landscape searches may offer unprecedented insights.
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Affiliation(s)
- Hindol Chatterjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Anshuman J Mahapatra
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Martin Zacharias
- Center for Functional Protein Assemblies, TUM School of Natural Sciences Technical University Munich, Ernst-Otto-Fischer-Straße 8, 85748 Garching, Germany.
| | - Neelanjana Sengupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India.
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Mitra S, Chandersekhar B, Li Y, Coopershlyak M, Mahoney ME, Evans B, Koenig R, Hall SCL, Klösgen B, Heinrich F, Deslouches B, Tristram-Nagle S. Novel non-helical antimicrobial peptides insert into and fuse lipid model membranes. SOFT MATTER 2024; 20:4088-4101. [PMID: 38712559 PMCID: PMC11109824 DOI: 10.1039/d4sm00220b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 04/26/2024] [Indexed: 05/08/2024]
Abstract
This research addresses the growing menace of antibiotic resistance by exploring antimicrobial peptides (AMPs) as alternatives to conventional antibiotics. Specifically, we investigate two linear amphipathic AMPs, LE-53 (12-mer) and LE-55 (16-mer), finding that the shorter LE-53 exhibits greater bactericidal activity against both Gram-negative (G(-)) and Gram-positive (G(+)) bacteria. Remarkably, both AMPs are non-toxic to eukaryotic cells. The heightened effectiveness of LE-53 is attributed to its increased hydrophobicity (H) compared to LE-55. Circular dichroism (CD) reveals that LE-53 and LE-55 both adopt β-sheet and random coil structures in lipid model membranes (LMMs) mimicking G(-) and G(+) bacteria, so secondary structure is not the cause of the potency difference. X-ray diffuse scattering (XDS) reveals increased lipid chain order in LE-53, a potential key distinction. Additionally, XDS study uncovers a significant link between LE-53's upper hydrocarbon location in G(-) and G(+) LMMs and its efficacy. Neutron reflectometry (NR) confirms the AMP locations determined using XDS. Solution small angle X-ray scattering (SAXS) demonstrates LE-53's ability to induce vesicle fusion in bacterial LMMs without affecting eukaryotic LMMs, offering a promising strategy to combat antibiotic-resistant strains while preserving human cell integrity, whereas LE-55 has a smaller ability to induce fusion.
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Affiliation(s)
- Saheli Mitra
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Bhairavi Chandersekhar
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Yunshu Li
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Mark Coopershlyak
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Margot E Mahoney
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Brandt Evans
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Rachel Koenig
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Stephen C L Hall
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK
| | - Beate Klösgen
- University of Southern Denmark, Dept. Physics, Chemistry & Pharmacy, PhyLife, Campusvej 55, Odense M5230, Denmark
| | - Frank Heinrich
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Berthony Deslouches
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Stephanie Tristram-Nagle
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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Golodnizky D, Bernardes CES, Davidovich-Pinhas M. Isotropic liquid state of cocoa butter. Food Chem 2024; 439:138066. [PMID: 38035493 DOI: 10.1016/j.foodchem.2023.138066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/15/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
The complex crystal structure of coca butter (CB) is responsible for the unique melting behavior, surface gloss, and mechanical properties of chocolate. While most studies concentrated on the crystalline state of CB, few studied the isotropic liquid state, which has a major impact on the crystallization process and the characteristics of the resulting crystals. In this study, the molecular organizations of the main CB triacylglycerols (TAGs; 1,3-dipalmitoyl-2-oleoylglycerol, palmitoyl-oleoyl-stearoylglycerol, POS, and 1,3-distearoyl-2-oleoylglycerol) were studied. The findings revealed the tunning-fork (Tf) conformation, commonly found in the crystalline state, is the least abundant in the isotropic liquid state of CB and pure TAGs. Notably, POS was found to interact with itself in CB, while its molecules with Tf conformation, although in small amounts in the mixture, tend to pair with each other at lower temperatures. These results highlight the significance of POS in CB crystallization and provide insights for developing CB alternatives.
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Affiliation(s)
- Daniel Golodnizky
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Carlos E S Bernardes
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
| | - Maya Davidovich-Pinhas
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel; Russell-Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
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Miyazaki M, Arisaka C, Nakagawara A, Sasaki N, Takahashi H, Takagi T, Amii H, Sonoyama M. Thermodynamic study on hydrated bilayers of ether-linked phosphatidylcholines with terminal perfluorobutyl group. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184261. [PMID: 38101595 DOI: 10.1016/j.bbamem.2023.184261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/01/2023] [Accepted: 12/07/2023] [Indexed: 12/17/2023]
Abstract
Novel terminally perfluorobutyl group-containing ether-linked phosphatidylcholines with different alkyl chain lengths (di-O-F4-Cn-PCs, n = 14,16 and 18) were developed as possible materials for stable liposomes aiming at applications of structural and functional analyses of membrane proteins. Differential scanning calorimetric investigations of the thermotropic transition of hydrated di-O-F4-Cn-PC bilayers demonstrated that the transition temperature of every di-O-F4-Cn-PC decreases by ~20 °C compared to their corresponding non-fluorinated PCs, di-O-Cn-PCs. With the elongation of the hydrophobic chain, on the other hand, the transition enthalpy (ΔH) and entropy (ΔS) increased in a linear manner. Comparison of ΔH and ΔS values against the net hydrocarbon chain length between di-O-F4-Cn-PCs and di-O-Cn-PCs strongly suggests that in the thermotropic transition of the di-O-F4-Cn-PC membrane, the perfluorobutyl segments undergo very limited structural changes; therefore, the hydrocarbon segments are mainly responsible for the phase transition.
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Affiliation(s)
- Masaya Miyazaki
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Chika Arisaka
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Ai Nakagawara
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Nanako Sasaki
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Hiroshi Takahashi
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Maebashi, Gunma 371-8510, Japan.
| | - Toshiyuki Takagi
- Cellular and Molecular Biotechnology Research Institute, AIST, Tsukuba, Ibaraki 305-8565, Japan.
| | - Hideki Amii
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan; Gunma University Initiative for Advanced Research (GIAR), Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Masashi Sonoyama
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan; Gunma University Initiative for Advanced Research (GIAR), Gunma University, Kiryu, Gunma 376-8515, Japan; Gunma University Center for Food Science and Wellness (GUCFW), Gunma University, Kiryu, Gunma 376-8515, Japan.
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7
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Pepe A, Moretti P, Yoneda JS, Carducci F, Itri R, Mariani P. Self-oriented anisotropic structure of G-hydrogels as a delicate balance between attractive and repulsive forces. NANOSCALE 2023; 15:15196-15205. [PMID: 37624640 DOI: 10.1039/d3nr01348k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
Guanine (G) hydrogels are very attractive materials made by the supramolecular organization of G-derivatives in water. In this paper, hydrogels composed of guanosine 5'-monophosphate (GMP) and guanosine (Gua), that make long, flexible and knotted G-quadruplexes, were investigated by small- and wide-angle X-ray scattering (SAXS and WAXS) to comprehend the origin of their unique orientational properties. The SAXS intensity, analysed at a fixed scattering vector modulus Q as a function of polar angle, allowed us to derive the Maier-Saupe orientation parameter m. The strong dependence of m on hydrogel composition and temperature demonstrated that the preferred orientation is controlled by the quadruplex surface charge and flexibility. Indeed, a possible correlation between the orientation parameter m and the quadruplex-to-quadruplex lateral interactions was explored. Results confirmed that the balance between attractive and repulsive interactions plays a main role in the orientational anisotropy: quadruplex clusters lose their orientational properties when attractive interactions decrease. The key role of the number of negative charges per unit length of the G-quadruplex filaments was confirmed by Atomic Force Microscopy (AFM) observations. Indeed, directionality histograms showed that in the presence of a large amount of Gua, G-quadruplexes follow preferential orientations other than those related to the strong interactions with the K+ pattern on the mica surface. The fact that lateral quadruplex-to-quadruplex interactions, even in the presence of external (opposing) forces, can tune the hydrogel alignment in a given preferred direction provides novel possibilities for scaffold/3D printing applications.
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Affiliation(s)
- Alessia Pepe
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy.
| | - Paolo Moretti
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy.
| | - Juliana S Yoneda
- Department of Applied Physics, Institute of Physics, University of São Paulo, São Paulo, Brazil
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Federica Carducci
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy.
| | - Rosangela Itri
- Department of Applied Physics, Institute of Physics, University of São Paulo, São Paulo, Brazil
| | - Paolo Mariani
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy.
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Zakany F, Mándity IM, Varga Z, Panyi G, Nagy P, Kovacs T. Effect of the Lipid Landscape on the Efficacy of Cell-Penetrating Peptides. Cells 2023; 12:1700. [PMID: 37443733 PMCID: PMC10340183 DOI: 10.3390/cells12131700] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Every cell biological textbook teaches us that the main role of the plasma membrane is to separate cells from their neighborhood to allow for a controlled composition of the intracellular space. The mostly hydrophobic nature of the cell membrane presents an impenetrable barrier for most hydrophilic molecules larger than 1 kDa. On the other hand, cell-penetrating peptides (CPPs) are capable of traversing this barrier without compromising membrane integrity, and they can do so on their own or coupled to cargos. Coupling biologically and medically relevant cargos to CPPs holds great promise of delivering membrane-impermeable drugs into cells. If the cargo is able to interact with certain cell types, uptake of the CPP-drug complex can be tailored to be cell-type-specific. Besides outlining the major membrane penetration pathways of CPPs, this review is aimed at deciphering how properties of the membrane influence the uptake mechanisms of CPPs. By summarizing an extensive body of experimental evidence, we argue that a more ordered, less flexible membrane structure, often present in the very diseases planned to be treated with CPPs, decreases their cellular uptake. These correlations are not only relevant for understanding the cellular biology of CPPs, but also for rationally improving their value in translational or clinical applications.
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Affiliation(s)
- Florina Zakany
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - István M. Mándity
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, 1085 Budapest, Hungary;
- TTK Lendület Artificial Transporter Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, 1117 Budapest, Hungary
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Peter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Tamas Kovacs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
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9
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Nagao M, Seto H. Neutron scattering studies on dynamics of lipid membranes. BIOPHYSICS REVIEWS 2023; 4:021306. [PMID: 38504928 PMCID: PMC10903442 DOI: 10.1063/5.0144544] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/01/2023] [Indexed: 03/21/2024]
Abstract
Neutron scattering methods are powerful tools for the study of the structure and dynamics of lipid bilayers in length scales from sub Å to tens to hundreds nm and the time scales from sub ps to μs. These techniques also are nondestructive and, perhaps most importantly, require no additives to label samples. Because the neutron scattering intensities are very different for hydrogen- and deuterium-containing molecules, one can replace the hydrogen atoms in a molecule with deuterium to prepare on demand neutron scattering contrast without significantly altering the physical properties of the samples. Moreover, recent advances in neutron scattering techniques, membrane dynamics theories, analysis tools, and sample preparation technologies allow researchers to study various aspects of lipid bilayer dynamics. In this review, we focus on the dynamics of individual lipids and collective membrane dynamics as well as the dynamics of hydration water.
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Affiliation(s)
| | - Hideki Seto
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan
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10
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Mitra S, Coopershlyak M, Li Y, Chandersekhar B, Koenig R, Chen MT, Evans B, Heinrich F, Deslouches B, Tristram-Nagle S. Novel Helical Trp- and Arg-Rich Antimicrobial Peptides Locate Near Membrane Surfaces and Rigidify Lipid Model Membranes. ADVANCED NANOBIOMED RESEARCH 2023; 3:2300013. [PMID: 37476397 PMCID: PMC10358585 DOI: 10.1002/anbr.202300013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023] Open
Abstract
Antibiotics are losing effectiveness as bacteria become resistant to conventional drugs. To find new alternatives, antimicrobial peptides (AMPs) are rationally designed with different lengths, charges, hydrophobicities (H), and hydrophobic moments (μH), containing only three types of amino acids: arginine, tryptophan, and valine. Six AMPs with low minimum inhibitory concentrations (MICs) and <25% toxicity to mammalian cells are selected for biophysical studies. Their secondary structures are determined using circular dichroism (CD), which finds that the % α-helicity of AMPs depends on composition of the lipid model membranes (LMMs): gram-negative (G(-)) inner membrane (IM) >gram-positive (G(+)) > Euk33 (eukaryotic with 33 mol% cholesterol). The two most effective peptides, E2-35 (16 amino acid [AA] residues) and E2-05 (22 AAs), are predominantly helical in G(-) IM and G(+) LMMs. AMP/membrane interactions such as membrane elasticity, chain order parameter, and location of the peptides in the membrane are investigated by low-angle and wide-angle X-ray diffuse scattering (XDS). It is found that headgroup location correlates with efficacy and toxicity. The membrane bending modulus KC displays nonmonotonic changes due to increasing concentrations of E2-35 and E2-05 in G(-) and G(+) LMMs, suggesting a bacterial killing mechanism where domain formation causes ion and water leakage.
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Affiliation(s)
- Saheli Mitra
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Mark Coopershlyak
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Yunshu Li
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Bhairavi Chandersekhar
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Rachel Koenig
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Mei-Tung Chen
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Brandt Evans
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
| | - Frank Heinrich
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
- Center for Neutron Research National Institute of Standards and Technology Gaithersburg, MD 20878, USA
| | - Berthony Deslouches
- Department of Environmental and Occupational Health University of Pittsburgh Pittsburgh, PA 15261, USA
| | - Stephanie Tristram-Nagle
- Biological Physics Group Physics Department Carnegie Mellon University Pittsburgh, PA 15213, USA
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11
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Structural diversity of photoswitchable sphingolipids for optodynamic control of lipid microdomains. Biophys J 2023:S0006-3495(23)00135-2. [PMID: 36869591 DOI: 10.1016/j.bpj.2023.02.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/22/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
Sphingolipids are a structurally diverse class of lipids predominantly found in the plasma membrane of eukaryotic cells. These lipids can laterally segregate with other rigid lipids and cholesterol into liquid-ordered domains that act as organizing centers within biomembranes. Owing the vital role of sphingolipids for lipid segregation, controlling their lateral organization is of utmost significance. Hence, we made use of the light-induced trans-cis isomerization of azobenzene-modified acyl chains to develop a set of photoswitchable sphingolipids with different headgroups (hydroxyl, galactosyl, phosphocholine) and backbones (sphingosine, phytosphingosine, tetrahydropyran-blocked sphingosine) that are able to shuttle between liquid-ordered and liquid-disordered regions of model membranes upon irradiation with UV-A (λ = 365 nm) and blue (λ = 470 nm) light, respectively. Using combined high-speed atomic force microscopy, fluorescence microscopy, and force spectroscopy, we investigated how these active sphingolipids laterally remodel supported bilayers upon photoisomerization, notably in terms of domain area changes, height mismatch, line tension, and membrane piercing. Hereby, we show that the sphingosine-based (Azo-β-Gal-Cer, Azo-SM, Azo-Cer) and phytosphingosine-based (Azo-α-Gal-PhCer, Azo-PhCer) photoswitchable lipids promote a reduction in liquid-ordered microdomain area when in the UV-adapted cis-isoform. In contrast, azo-sphingolipids having tetrahydropyran groups that block H-bonding at the sphingosine backbone (lipids named Azo-THP-SM, Azo-THP-Cer) induce an increase in the liquid-ordered domain area when in cis, accompanied by a major rise in height mismatch and line tension. These changes were fully reversible upon blue light-triggered isomerization of the various lipids back to trans, pinpointing the role of interfacial interactions for the formation of stable liquid-ordered domains.
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12
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Pro-inflammatory protein S100A9 alters membrane organization by dispersing ordered domains. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184113. [PMID: 36567033 DOI: 10.1016/j.bbamem.2022.184113] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/06/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
Pro-inflammatory, calcium-binding protein S100A9 is localized in the cytoplasm of many cells and regulates several intracellular and extracellular processes. S100A9 is involved in neuroinflammation associated with the pathogenesis of Alzheimer's disease (AD). The number of studies on the impact of S100A9 in co-aggregation processes with amyloid-like proteins is increasing. However, there is still a lack of data on how this protein interacts with lipid membranes. We employed atomic force microscopy (AFM), dynamic light scattering (DLS), and fluorescence measurements (Laurdan and Thioflavin-T) to study the interaction between protein and the membrane surface. We used lipid vesicles in bulk and planar tethered lipid bilayers as biomimetic membrane models. We demonstrated that the protein accumulates on negatively charged lipid bilayers but with no further loss of the bilayer's integrity. The most important result is that the initial adsorption and accumulation of apo-form of S100A9 on the lipid membrane surface is lipid phase-sensitive. The breaking down of raft-like and disappearance of gel-like domains indicate that protein incorporates into the hydrophobic part of the lipid bilayer. We observed the most noticeable loss of integrity in lipid bilayers constructed from a lipid mixture (brain total lipid extract). Understanding the function and interactions of these proteins in cellular environments might expand the development of new diagnostic and therapeutic approaches for AD or other related diseases.
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13
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Gater DL, Hughes K, Stojanoff V, Isakovic AF. Phase Heterogeneity in Cholesterol-Containing Ternary Phospholipid Lamellar Phases. ACS OMEGA 2023; 8:6225-6233. [PMID: 36844553 PMCID: PMC9947962 DOI: 10.1021/acsomega.2c04914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/14/2022] [Indexed: 06/18/2023]
Abstract
Pseudo-ternary mixtures of lamellar phase phospholipids (DPPC and brain sphingomyelin with cholesterol) were studied below T m while comparing the influence of cholesterol content, temperature, and the presence of small quantities of vitamin D binding protein (DBP) or vitamin D receptor (VDR). The measurements, conducted by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR), cover a range of cholesterol concentrations (20% mol. wt to 40% mol. wt.) and physiologically relevant temperature range (294-314 K). In addition to rich intraphase behavior, data and modeling are used to approximate the lipids' headgroup location variations under the abovementioned experimental conditions.
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Affiliation(s)
| | - Keontré
I. Hughes
- Colgate
University, Hamilton, New York 13346-1338, United States
- Michigan
State University, East Lansing, Michigan 48824-1312, United States
| | - Vivian Stojanoff
- Brookhaven
National Laboratory, Upton, New York 11973-5000, United States
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14
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Porras-Gómez M, Kim H, Dronadula MT, Kambar N, Metellus CJB, Aluru NR, van der Zande A, Leal C. Multiscale compression-induced restructuring of stacked lipid bilayers: From buckling delamination to molecular packing. PLoS One 2022; 17:e0275079. [PMID: 36490254 PMCID: PMC9733850 DOI: 10.1371/journal.pone.0275079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
Lipid membranes in nature adapt and reconfigure to changes in composition, temperature, humidity, and mechanics. For instance, the oscillating mechanical forces on lung cells and alveoli influence membrane synthesis and structure during breathing. However, despite advances in the understanding of lipid membrane phase behavior and mechanics of tissue, there is a critical knowledge gap regarding the response of lipid membranes to micromechanical forces. Most studies of lipid membrane mechanics use supported lipid bilayer systems missing the structural complexity of pulmonary lipids in alveolar membranes comprising multi-bilayer interconnected stacks. Here, we elucidate the collective response of the major component of pulmonary lipids to strain in the form of multi-bilayer stacks supported on flexible elastomer substrates. We utilize X-ray diffraction, scanning probe microscopy, confocal microscopy, and molecular dynamics simulation to show that lipid multilayered films both in gel and fluid states evolve structurally and mechanically in response to compression at multiple length scales. Specifically, compression leads to increased disorder of lipid alkyl chains comparable to the effect of cholesterol on gel phases as a direct result of the formation of nanoscale undulations in the lipid multilayers, also inducing buckling delamination and enhancing multi-bilayer alignment. We propose this cooperative short- and long-range reconfiguration of lipid multilayered films under compression constitutes a mechanism to accommodate stress and substrate topography. Our work raises fundamental insights regarding the adaptability of complex lipid membranes to mechanical stimuli. This is critical to several technologies requiring mechanically reconfigurable surfaces such as the development of electronic devices interfacing biological materials.
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Affiliation(s)
- Marilyn Porras-Gómez
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Hyunchul Kim
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Mohan Teja Dronadula
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas, United States of America
| | - Nurila Kambar
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Christopher J. B. Metellus
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Narayana R. Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas, United States of America
| | - Arend van der Zande
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America,* E-mail: (AZ); (CL)
| | - Cecília Leal
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America,* E-mail: (AZ); (CL)
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15
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Translating a Thin-Film Rehydration Method to Microfluidics for the Preparation of a SARS-CoV-2 DNA Vaccine: When Manufacturing Method Matters. Pharmaceutics 2022; 14:pharmaceutics14071427. [PMID: 35890321 PMCID: PMC9316859 DOI: 10.3390/pharmaceutics14071427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 01/21/2023] Open
Abstract
Previous investigations conducted on a liposomal formulation for a SARS-CoV-2 DNA vaccine manufactured using the thin-film layer rehydration method showed promising immunogenicity results in mice. The adaptation of the liposomal formulation to a scalable and reproducible method of manufacture is necessary to continue the investigation of this vaccine candidate. Microfluidics manufacture shows high potential in method translation. The physicochemical characterization of the blank liposomes produced by thin-film layer rehydration or microfluidics were shown to be comparable. However, a difference in lipid nanostructure in the bilayer resulted in a significant difference in the hydration of the thin-film liposomes, ultimately altering their complexation behavior. A study on the complexation of liposomes with the DNA vaccine at various N/P ratios showed different sizes and Zeta-potential values between the two formulations. This difference in the complexation behavior resulted in distinct immunogenicity profiles in mice. The thin-film layer rehydration-manufactured liposomes induced a significantly higher response compared to the microfluidics-manufactured samples. The nanostructural analysis of the two samples revealed the critical importance of understanding the differences between the two formulations that resulted in the different immunogenicity in mice.
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16
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Golodnizky D, Shmidov Y, Bitton R, Bernardes CE, Davidovich-Pinhas M. Isotropic liquid state of triacylglycerols. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118703] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Nguyen HL, Man VH, Li MS, Derreumaux P, Wang J, Nguyen PH. Elastic moduli of normal and cancer cell membranes revealed by molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:6225-6237. [PMID: 35229839 DOI: 10.1039/d1cp04836h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recent studies indicate that there are mechanical differences between normal cells and cancer cells. Because the cell membrane takes part in a variety of vital processes, we test the hypothesis of whether or not two fundamental alterations in the cell membrane, i.e., the overexpression of phosphatidylserine lipids in the outer leaflet and a reduction in cholesterol concentration, could cause the softening in cancer cells. Adopting ten models of normal and cancer cell membranes, we carry out 1 μs all-atom molecular dynamics simulations to compare the structural properties and elasticity properties of two membrane types. We find that the overexpression of the phosphatidylserine lipids in the outer leaflet does not significantly alter the area per lipid, the membrane thickness, the lipid order parameters and the elasticity moduli of the cancer membranes. However, a reduction in the cholesterol concentration leads to clear changes in those quantities, especially decreases in the bending, tilt and twist moduli. This implies that the reduction of cholesterol concentration in the cancer membranes could contribute to the softening of cancer cells.
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Affiliation(s)
- Hoang Linh Nguyen
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Viet Hoang Man
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Mai Suan Li
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam.,Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Philippe Derreumaux
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France
| | - Junmei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Phuong H Nguyen
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France.,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild, PSL Research University, Paris, France.
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18
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It Takes More than Two to Tango: Complex, Hierarchal, and Membrane-Modulated Interactions in the Regulation of Receptor Tyrosine Kinases. Cancers (Basel) 2022; 14:cancers14040944. [PMID: 35205690 PMCID: PMC8869822 DOI: 10.3390/cancers14040944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/09/2022] [Accepted: 02/12/2022] [Indexed: 12/18/2022] Open
Abstract
The search for an understanding of how cell fate and motility are regulated is not a purely scientific undertaking, but it can also lead to rationally designed therapies against cancer. The discovery of tyrosine kinases about half a century ago, the subsequent characterization of certain transmembrane receptors harboring tyrosine kinase activity, and their connection to the development of human cancer ushered in a new age with the hope of finding a treatment for malignant diseases in the foreseeable future. However, painstaking efforts were required to uncover the principles of how these receptors with intrinsic tyrosine kinase activity are regulated. Developments in molecular and structural biology and biophysical approaches paved the way towards better understanding of these pathways. Discoveries in the past twenty years first resulted in the formulation of textbook dogmas, such as dimerization-driven receptor association, which were followed by fine-tuning the model. In this review, the role of molecular interactions taking place during the activation of receptor tyrosine kinases, with special attention to the epidermal growth factor receptor family, will be discussed. The fact that these receptors are anchored in the membrane provides ample opportunities for modulatory lipid-protein interactions that will be considered in detail in the second part of the manuscript. Although qualitative and quantitative alterations in lipids in cancer are not sufficient in their own right to drive the malignant transformation, they both contribute to tumor formation and also provide ways to treat cancer. The review will be concluded with a summary of these medical aspects of lipid-protein interactions.
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19
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Abstract
The ability of cholesterol to uncoil (i.e., condense) the acyl chains of phospholipids has been known for a century. Despite extensive studies of the interactions between cholesterol and phospholipids, a molecular-level understanding of this uncoiling phenomenon has remained elusive. Equally unclear has been whether cholesterol's two different faces (i.e., its relatively smooth α face and its relatively rough β face) contribute to its condensing power. Because cholesterol's condensing effect is believed to play a major role in controlling the fluidity, structure, and functioning of all animal cell membranes, its biological importance cannot be overstated. This Perspective focuses on experimental evidence that addresses (i) the credibility of a popular "umbrella" mechanism that has been used to account for cholesterol's condensing effect, (ii) the credibility of an alternate "template" mechanism, (iii) the importance of cholesterol two-faced character with respect to its condensing power, and (iv) the viability of a surface occupancy model.
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20
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Kaddah S, Khreich N, Kaddah F, Charcosset C, Greige-Gerges H. Pentacyclic triterpenes modulate liposome membrane fluidity and permeability depending on membrane cholesterol content. Int J Pharm 2021; 610:121232. [PMID: 34744000 DOI: 10.1016/j.ijpharm.2021.121232] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/05/2021] [Accepted: 10/23/2021] [Indexed: 12/08/2022]
Abstract
Since the membrane-related processes represent an integral part of the biological activities of drugs, their effect on the membrane dynamics is actually considered. In this study, we investigated the effect of pentacyclic triterpenes (TTPs), oleanolic acid (OA) and erythrodiol (ER), on the fluidity and permeability of liposomes membranes differing by their cholesterol content. All liposomes were prepared by reverse phase evaporation technique (REV). Spin-labeled liposomes exposed or not to TTPs were used for fluidity studies by using 5- and 16-doxyl stearic acids (DSA). TTPs-loaded liposomes (phospholipid:cholesterol of 1:1), and preformed vesicles exposed to TTPs were used for permeability studies by monitoring the release of sulforhodamine B (SRB) at 37 °C. The apparent release constants of SRB were determined by Higuchi model based on a biphasic curve shape (0-10 h; 10-48 h). TTPs-loaded liposomes were characterized for their size and homogeneity. Results showed that ER increased the membrane fluidity at the upper region of the membrane while the both TTPs produced a condensing effect at the deeper region of the membrane. The membrane composition was a critical parameter modulating the effect of TTPs on the membrane permeability. Also, this study consolidated the fact that a fluidizing membrane agent is not necessarily a permeabilizing-membrane compound.
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Affiliation(s)
- Samar Kaddah
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon; Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, France
| | - Nathalie Khreich
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon
| | - Fouad Kaddah
- École Supérieure d'ingénieurs de Beyrouth, Université Saint Joseph, Beyrouth, Mar Roukoz-Dekwaneh, Lebanon
| | | | - Hélène Greige-Gerges
- Bioactive Molecules Research Laboratory, Faculty of Sciences, Lebanese University, Lebanon.
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21
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Boonnoy P, Jarerattanachat V, Karttunen M, Wong-Ekkabut J. Role of cholesterol flip-flop in oxidized lipid bilayers. Biophys J 2021; 120:4525-4535. [PMID: 34478697 PMCID: PMC8553637 DOI: 10.1016/j.bpj.2021.08.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 08/13/2021] [Accepted: 08/26/2021] [Indexed: 11/21/2022] Open
Abstract
We performed a series of molecular dynamics simulations of cholesterol (Chol) in nonoxidized 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine (PLPC) bilayer and in binary mixtures of PLPC-oxidized-lipid-bilayers with 0-50% Chol concentration and oxidized lipids with hydroperoxide and aldehyde oxidized functional groups. From the 60 unbiased molecular dynamics simulations (total of 161 μs), we found that Chol inhibited pore formation in the aldehyde-containing oxidized lipid bilayers at concentrations greater than 11%. For both pure PLPC bilayer and bilayers with hydroperoxide lipids, no pores were observed at any Chol concentration. Furthermore, increasing cholesterol concentration led to a change of phase state from the liquid-disordered to the liquid-ordered phase. This condensing effect of Chol was observed in all systems. Data analysis shows that the addition of Chol results in an increase in bilayer thickness. Interestingly, we observed Chol flip-flop only in the aldehyde-containing lipid bilayer but neither in the PLPC nor the hydroperoxide bilayers. Umbrella-sampling simulations were performed to calculate the translocation free energies and the Chol flip-flop rates. The results show that Chol's flip-flop rate depends on the lipid bilayer type, and the highest rate are found in aldehyde bilayers. As the main finding, we shown that Chol stabilizes the oxidized lipid bilayer by confining the distribution of the oxidized functional groups.
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Affiliation(s)
- Phansiri Boonnoy
- Department of Physics, Kasetsart University, Bangkok, Thailand; Computational Biomodelling Laboratory for Agricultural Science and Technology, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Viwan Jarerattanachat
- Computational Biomodelling Laboratory for Agricultural Science and Technology, Faculty of Science, Kasetsart University, Bangkok, Thailand; Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, Bangkok, Thailand; NSTDA Supercomputer Center, National Electronics and Computer Technology Center, National Science and Technology Development Agency, Khlong Luang, Pathumthani, Thailand
| | - Mikko Karttunen
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada; Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada; The Centre for Advanced Materials Research, The University of Western Ontario, London, Ontario, Canada
| | - Jirasak Wong-Ekkabut
- Department of Physics, Kasetsart University, Bangkok, Thailand; Computational Biomodelling Laboratory for Agricultural Science and Technology, Faculty of Science, Kasetsart University, Bangkok, Thailand; Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, Bangkok, Thailand; Specialized Center of Rubber and Polymer Materials for Agriculture and Industry, Faculty of Science, Kasetsart University, Bangkok, Thailand.
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22
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Bouquiaux C, Castet F, Champagne B. Unravelling the Effects of Cholesterol on the Second-Order Nonlinear Optical Responses of Di-8-ANEPPS Dye Embedded in Phosphatidylcholine Lipid Bilayers. J Phys Chem B 2021; 125:10195-10212. [PMID: 34491062 DOI: 10.1021/acs.jpcb.1c05630] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cholesterol is known for its role in maintaining the correct fluidity and rigidity of the animals cell membranes and thus their functions. Assessing the content and the role of cholesterol in lipid bilayers is therefore of crucial importance for a deeper understanding and control of membrane functioning. In this computational work, we investigate bilayers built from three types of glycerophospholipid phosphatidylcholine (PC) lipids, namely dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and dioleoylphosphatidylcholine (DOPC), and containing different amounts of cholesterol by analyzing the second-harmonic generation (SHG) nonlinear optical (NLO) response of a probe molecule, di-8-ANEPPS, inserted into the membranes. This molecular property presents the advantage to be specific to interfacial regions such as lipid bilayers. To unravel these effects, Molecular Dynamics (MD) simulations have been performed on both DPPC and DOPC lipids by varying the cholesterol mole fraction (from 0 to 0.66), while POPC was only considered as a pure bilayer. In the case of the structural properties of the bilayers, all the analyses converge toward the same conclusion: as the mole fraction of cholesterol increases, the systems become more rigid, confirming the condensing effect of cholesterol. In addition, the chromophore is progressively more aligned with respect to the normal to the bilayer. On the contrary, addition of unsaturation disorders the lipid bilayers, with barely no impact on the alignment of the chromophore. Then, using the frames obtained from the MD simulations, the first hyperpolarizability β of the dye in its environment has been computed at the TDDFT level. On the one hand, the addition of cholesterol induces a progressive increase of the diagonal component the β tensor parallel to the bilayer normal. On the other hand, larger β values have been calculated for the unsaturated than for the saturated lipid systems. In summary, this study illustrates the relationship between the composition and structure of the bilayers and the NLO responses of the embedded dye.
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Affiliation(s)
- Charlotte Bouquiaux
- Theoretical Chemistry Lab, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, rue de Bruxelles, 61, B-5000 Namur, Belgium
| | - Frédéric Castet
- , Institut des Sciences Moléculaires, UMR 5255 CNRS, University of Bordeaux, cours de la Libération 351, F-33405 Talence Cedex, France
| | - Benoît Champagne
- Theoretical Chemistry Lab, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, rue de Bruxelles, 61, B-5000 Namur, Belgium
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23
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Nagao M, Kelley EG, Faraone A, Saito M, Yoda Y, Kurokuzu M, Takata S, Seto M, Butler PD. Relationship between Viscosity and Acyl Tail Dynamics in Lipid Bilayers. PHYSICAL REVIEW LETTERS 2021; 127:078102. [PMID: 34459628 DOI: 10.1103/physrevlett.127.078102] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Membrane viscosity is a fundamental property that controls molecular transport and structural rearrangements in lipid membranes. Given its importance in many cell processes, various experimental and computational methods have been developed to measure the membrane viscosity, yet the estimated values depend highly on the method and vary by orders of magnitude. Here we investigate the molecular origins of membrane viscosity by measuring the nanoscale dynamics of the lipid acyl tails using x-ray and neutron spectroscopy techniques. The results show that the membrane viscosity can be estimated from the structural relaxation times of the lipid tails.
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Affiliation(s)
- Michihiro Nagao
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115, USA
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - Elizabeth G Kelley
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA
| | - Antonio Faraone
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA
| | - Makina Saito
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Osaka, 590-0494, Japan
| | - Yoshitaka Yoda
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo, 679-5198, Japan
| | - Masayuki Kurokuzu
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Osaka, 590-0494, Japan
| | - Shinichi Takata
- J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan
| | - Makoto Seto
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Osaka, 590-0494, Japan
| | - Paul D Butler
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, USA
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, USA
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24
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Bochicchio D, Cantu L, Cadario MV, Palchetti L, Natali F, Monticelli L, Rossi G, Del Favero E. Polystyrene perturbs the structure, dynamics, and mechanical properties of DPPC membranes: An experimental and computational study. J Colloid Interface Sci 2021; 605:110-119. [PMID: 34311305 DOI: 10.1016/j.jcis.2021.07.069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/16/2021] [Accepted: 07/09/2021] [Indexed: 12/14/2022]
Abstract
Synthetic plastic oligomers can interact with the cells of living organisms by different ways. They can be intentionally administered to the human body as part of nanosized biomedical devices. They can be inhaled by exposed workers, during the production of multicomponent, polymer-based nanocomposites. They can leak out of food packaging. Most importantly, they can result from the degradation of plastic waste, and enter the food chain. A physicochemical characterization of the effects of synthetic polymers on the structure and dynamics of cell components is still lacking. Here, we combine a wide spectrum of experimental techniques (calorimetry, x-ray, and neutron scattering) with atomistic Molecular Dynamics simulations to study the interactions between short chains of polystyrene (25 monomers) and model lipid membranes (DPPC, in both gel and fluid phase). We find that doping doses of polystyrene oligomers alter the thermal properties of DPPC, stabilizing the fluid lipid phase. They perturb the membrane structure and dynamics, in a concentration-dependent fashion. Eventually, they modify the mechanical properties of DPPC, reducing its bending modulus in the fluid phase. Our results call for a systematic, interdisciplinary assessment of the mechanisms of interaction of synthetic, everyday use polymers with cell membranes.
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Affiliation(s)
- Davide Bochicchio
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genoa, Italy
| | - Laura Cantu
- Department of Medical Biotechnology and Translational Medicine, University of Milan, LITA V.le F.lli Cervi 93, 20090 Segrate, Italy
| | - Maria Vittoria Cadario
- Department of Medical Biotechnology and Translational Medicine, University of Milan, LITA V.le F.lli Cervi 93, 20090 Segrate, Italy
| | - Leonardo Palchetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, LITA V.le F.lli Cervi 93, 20090 Segrate, Italy
| | - Francesca Natali
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Luca Monticelli
- IBCP, CNRS, UMR 5086, 7 Passage du Vercors, 69007 Lyon, France
| | - Giulia Rossi
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genoa, Italy.
| | - Elena Del Favero
- Department of Medical Biotechnology and Translational Medicine, University of Milan, LITA V.le F.lli Cervi 93, 20090 Segrate, Italy.
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25
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Zec N, Mangiapia G, Hendry AC, Barker R, Koutsioubas A, Frielinghaus H, Campana M, Ortega-Roldan JL, Busch S, Moulin JF. Mutually Beneficial Combination of Molecular Dynamics Computer Simulations and Scattering Experiments. MEMBRANES 2021; 11:507. [PMID: 34357157 PMCID: PMC8304056 DOI: 10.3390/membranes11070507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022]
Abstract
We showcase the combination of experimental neutron scattering data and molecular dynamics (MD) simulations for exemplary phospholipid membrane systems. Neutron and X-ray reflectometry and small-angle scattering measurements are determined by the scattering length density profile in real space, but it is not usually possible to retrieve this profile unambiguously from the data alone. MD simulations predict these density profiles, but they require experimental control. Both issues can be addressed simultaneously by cross-validating scattering data and MD results. The strengths and weaknesses of each technique are discussed in detail with the aim of optimizing the opportunities provided by this combination.
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Affiliation(s)
- Nebojša Zec
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Gaetano Mangiapia
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Alex C. Hendry
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK; (A.C.H.); (J.L.O.-R.)
| | - Robert Barker
- School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK;
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (A.K.); (H.F.)
| | - Henrich Frielinghaus
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (A.K.); (H.F.)
| | - Mario Campana
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, UK;
| | | | - Sebastian Busch
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Jean-François Moulin
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
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26
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Alves ED, de Andrade DX, de Almeida AR, Colherinhas G. Atomistic molecular dynamics study on the influence of high temperatures on the structure of peptide nanomembranes candidates for organic supercapacitor electrode. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116126] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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27
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Coppens E, Desmaële D, Mougin J, Tusseau-Nenez S, Couvreur P, Mura S. Gemcitabine Lipid Prodrugs: The Key Role of the Lipid Moiety on the Self-Assembly into Nanoparticles. Bioconjug Chem 2021; 32:782-793. [PMID: 33797231 DOI: 10.1021/acs.bioconjchem.1c00051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A small library of amphiphilic prodrugs has been synthesized by conjugation of gemcitabine (Gem) (a hydrophilic nucleoside analogue) to a series of lipid moieties and investigated for their capacity to spontaneously self-assemble into nanosized objects by simple nanoprecipitation. Four of these conjugates formed stable nanoparticles (NPs), while with the others, immediate aggregation occurred, whatever the tested experimental conditions. Whether such capacity could have been predicted based on the prodrug physicochemical features was a matter of question. Among various parameters, the hydrophilic-lipophilic balance (HLB) value seemed to hold a predictive character. Indeed, we identified a threshold value which well correlated with the tendency (or not) of the synthesized prodrugs to form stable nanoparticles. Such a hypothesis was further confirmed by broadening the analysis to Gem and other nucleoside prodrugs already described in the literature. We also observed that, in the case of Gem prodrugs, the lipid moiety affected not only the colloidal properties but also the in vitro anticancer efficacy of the resulting nanoparticles. Overall, this study provides a useful demonstration of the predictive potential of the HLB value for lipid prodrug NP formulation and highlights the need of their opportune in vitro screening, as optimal drug loading does not always translate in an efficient biological activity.
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Affiliation(s)
- Eleonore Coppens
- Institut Galien Paris-Saclay, UMR 8612, CNRS, Université Paris-Saclay, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 cedex Châtenay-Malabry, France
| | - Didier Desmaële
- Institut Galien Paris-Saclay, UMR 8612, CNRS, Université Paris-Saclay, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 cedex Châtenay-Malabry, France
| | - Julie Mougin
- Institut Galien Paris-Saclay, UMR 8612, CNRS, Université Paris-Saclay, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 cedex Châtenay-Malabry, France
| | - Sandrine Tusseau-Nenez
- Laboratoire de Physique de la Matière Condensée (PMC), CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
| | - Patrick Couvreur
- Institut Galien Paris-Saclay, UMR 8612, CNRS, Université Paris-Saclay, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 cedex Châtenay-Malabry, France
| | - Simona Mura
- Institut Galien Paris-Saclay, UMR 8612, CNRS, Université Paris-Saclay, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 cedex Châtenay-Malabry, France
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28
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Loney RW, Brandner B, Dagan MP, Smith PN, Roche M, Fritz JR, Hall SB, Tristram-Nagle SA. Changes in membrane elasticity caused by the hydrophobic surfactant proteins correlate poorly with adsorption of lipid vesicles. SOFT MATTER 2021; 17:3358-3366. [PMID: 33630985 PMCID: PMC8016726 DOI: 10.1039/d0sm02223c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
To establish how the hydrophobic surfactant proteins, SP-B and SP-C, promote adsorption of lipids to an air/water interface, we used X-ray diffuse scattering (XDS) to determine an order parameter of the lipid chains (Sxray) and the bending modulus of the lipid bilayers (KC). Samples contained different amounts of the proteins with two sets of lipids. Dioleoylphosphatidylcholine (DOPC) provided a simple, well characterized model system. The nonpolar and phospholipids (N&PL) from extracted calf surfactant provided the biological mix of lipids. For both systems, the proteins produced changes in Sxray that correlated well with KC. The dose-response to the proteins, however, differed. Small amounts of protein generated large decreases in Sxray and KC for DOPC that progressed monotonically. The changes for the surfactant lipids were erratic. Our studies then tested whether the proteins produced correlated effects on adsorption. Experiments measured the initial fall in surface tension during adsorption to a constant surface area, and then expansion of the interface during adsorption at a constant surface tension of 40 mN m-1. The proteins produced a sigmoidal increase in the rate of adsorption at 40 mN m-1 for both lipids. The results correlated poorly with the changes in Sxray and KC in both cases. Disordering of the lipid chains produced by the proteins, and the softening of the bilayers, fail to explain how the proteins promote adsorption of lipid vesicles.
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Affiliation(s)
- Ryan W Loney
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon 97239, USA.
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29
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Fritz JR, Loney RW, Hall SB, Tristram-Nagle S. Suppression of L α/L β Phase Coexistence in the Lipids of Pulmonary Surfactant. Biophys J 2020; 120:243-253. [PMID: 33347885 DOI: 10.1016/j.bpj.2020.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/17/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
To determine how different constituents of pulmonary surfactant affect its phase behavior, we measured wide-angle x-ray scattering (WAXS) from oriented bilayers. Samples contained the nonpolar and phospholipids (N&PL) obtained from calf lung surfactant extract (CLSE), which also contains the hydrophobic surfactant proteins SP-B and SP-C. Mixtures with different ratios of N&PL and CLSE provided the same set of lipids with different amounts of the proteins. At 37°C, N&PL by itself forms coexisting Lα and Lβ phases. In the Lβ structure, the acyl chains of the phospholipids occupy an ordered array that has melted by 40°C. This behavior suggests that the Lβ composition is dominated by dipalmitoyl phosphatidylcholine (DPPC), which is the most prevalent component of CLSE. The Lβ chains, however, lack the tilt of the Lβ' phase formed by pure DPPC. At 40°C, WAXS also detects an additional diffracted intensity, the location of which suggests a correlation among the phospholipid headgroups. The mixed samples of N&PL with CLSE show that increasing amounts of the proteins disrupt both the Lβ phase and the headgroup correlation. With physiological levels of the proteins in CLSE, both types of order are absent. These results with bilayers at physiological temperatures indicate that the hydrophobic surfactant proteins disrupt the ordered structures that have long been considered essential for the ability of pulmonary surfactant to sustain low surface tensions. They agree with prior fluorescence micrographic results from monomolecular films of CLSE, suggesting that at physiological temperatures, any ordered phase is likely to be absent or occupy a minimal interfacial area.
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Affiliation(s)
- Jonathan R Fritz
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Ryan W Loney
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - Stephen B Hall
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon.
| | - Stephanie Tristram-Nagle
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania.
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30
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Souza LM, Souza FR, Reynaud F, Pimentel AS. Tuning the hydrophobicity of a coarse grained model of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine using the experimental octanol-water partition coefficient. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114132] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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31
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Kamble S, Patil S, Kulkarni M, Appala VRM. Interleaflet Decoupling in a Lipid Bilayer at Excess Cholesterol Probed by Spectroscopic Ellipsometry and Simulations. J Membr Biol 2020; 253:647-659. [PMID: 33221946 DOI: 10.1007/s00232-020-00156-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/11/2020] [Indexed: 11/26/2022]
Abstract
Artificial lipid membranes are often investigated as a replica of the cell membrane in the form of supported lipid bilayers (SLBs). In SLBs, the phase state of a lipid bilayer strongly depends on the presence of molecules such as cholesterol, ceramide, and physical parameters such as temperature. Cholesterol is a key molecule of biological membranes and it exerts condensing effect on lipid bilayers. In this paper, we demonstrate the influence of excess cholesterol content on a supported lipid bilayer of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) (fluid-phase) using spectroscopic ellipsometry (SE) and coarse-grained (CG) molecular dynamics (MD) simulations. The results show the condensation effect due to cholesterol addition up to 30% and interleaflet decoupling at excess cholesterol beyond 30%. SE results show the separation of individual leaflets of the bilayer and influence of cholesterol on the biophysical properties such as thickness and optical index. CG simulations were performed at different ratios of DOPC:cholesterol mixtures to explore cholesterol-driven bilayer properties and stability. The simulations displayed the accumulation of cholesterol molecules at the interface of the lower and upper leaflets of the bilayer, thus leading to undulations in the bilayer. This work reports the successful application of SE technique to study lipid-cholesterol interactions for the first time.
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Affiliation(s)
- Sagar Kamble
- Department of Applied Physics, Defence Institute of Advanced Technology (DIAT) DU, Girinagar, Pune, India
| | - Snehal Patil
- Department of Applied Physics, Defence Institute of Advanced Technology (DIAT) DU, Girinagar, Pune, India
| | - Mandar Kulkarni
- Division of Biophysical Chemistry, Chemical Center, Lund University, 22100, Lund, Sweden.
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32
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Andrade D, Colherinhas G. The influence of polar and non-polar interactions on the self-assembly of peptide nanomembranes and their applications: An atomistic study using classical molecular dynamics. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114263] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Lee BL, Kuczera K, Lee KH, Childs EW, Jas GS. Unassisted N-acetyl-phenylalanine-amide transport across membrane with varying lipid size and composition: kinetic measurements and atomistic molecular dynamics simulation. J Biomol Struct Dyn 2020; 40:1445-1460. [PMID: 33034537 DOI: 10.1080/07391102.2020.1827037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Biological membranes are essential to preserve structural integrity and regulate functional properties through the permeability of nutrients, pharmaceutical drugs, and neurotransmitters of a living cell. The movement of acetylated and amidated phenylalanine (NAFA) across 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane bilayers is investigated to probe physical transport. The rate of transport is measured experimentally applying parallel artificial membrane permeation assay (PAMPA). At the physiological temperature, 310 K, the measured time constants in the neutral pH were ∼6 h in DOPC and ∼3 h in POPC, while in a more acidic condition, at a pH 4.8, the time constants were ∼8 h in both lipids. Computationally, we have expanded our transport study of three aromatic dipeptides across a bilayer composed of DOPC18. In this study, we have examined the effects of lipid composition and bilayer size on the passive transport of NAFA by simulating the dipeptide in three different bilayers, with 50 DOPC lipids, 50 POPC lipids, and 40 POPC molecules. Specifically, atomistic molecular dynamics simulations with umbrella sampling were used to calculate the potential of mean force for the passive permeation of NAFA across the bilayers. Diffusion constants were then calculated by numerically solving the Smoluchowski equation. Permeability coefficients and mean first passage times were then calculated. Structural properties - Ramachandran plots, sidechain torsions, peptide insertion angles, radial distribution functions, and proximal peptide water molecules - were also examined to determine the effect of system size and lipid type. In terms of systems size, we observed a small decrease in the highest barrier of the potential of mean force and fewer sampled sidechain dihedral angle conformations with 40 versus 50 POPC lipids due to weaker membrane deformations within a smaller lipid bilayer. In terms of lipid type, DOPC contains two monounsaturated acyl chains compared to only one such acyl chain in POPC; therefore, DOPC bilayers are less ordered and more easily deformed, as seen by a much broader potential of mean force profile. The NAFA in DOPC lipid also transitioned to an internally hydrogen-bonded backbone conformation at lower membrane depths than in POPC. Similarly, as for other aromatic dipeptides, NAFA tends to insert into the membrane sidechain-first, remains mostly desolvated in the membrane center, and exhibits slow reorientations within the bilayer in both DOPC and POPC. With a joint experimental and computational study we have gained a new insight into the rate of transport and the underlying microscopic mechanism in different lipid bilayer conditions of the simplest hydrophobic aromatic dipeptide.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Brent L Lee
- Department of Chemistry, The University of Kansas, Lawrence, KS, USA
| | - Krzysztof Kuczera
- Department of Chemistry, The University of Kansas, Lawrence, KS, USA.,Department of Molecular Biosciences, The University of Kansas, Lawrence, KS, USA
| | - Kyung-Hoon Lee
- Department of Biology, Chowan University, Murfreesboro, NC, USA
| | - Ed W Childs
- Department of Surgery, Morehouse School of Medicine, Atlanta, GA, USA
| | - Gouri S Jas
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS, USA
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34
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Assessing the DOPC-cholesterol interactions and their influence on fullerene C60 partitioning in lipid bilayers. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113698] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Lu J, Mazidi H, Ding T, Zhang O, Lew MD. Single-Molecule 3D Orientation Imaging Reveals Nanoscale Compositional Heterogeneity in Lipid Membranes. Angew Chem Int Ed Engl 2020; 59:17572-17579. [PMID: 32648275 PMCID: PMC7794097 DOI: 10.1002/anie.202006207] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/15/2020] [Indexed: 12/21/2022]
Abstract
In soft matter, thermal energy causes molecules to continuously translate and rotate, even in crowded environments, thereby impacting the spatial organization and function of most molecular assemblies, such as lipid membranes. Directly measuring the orientation and spatial organization of large collections (>3000 molecules μm-2 ) of single molecules with nanoscale resolution remains elusive. In this paper, we utilize SMOLM, single-molecule orientation localization microscopy, to directly measure the orientation spectra (3D orientation plus "wobble") of lipophilic probes transiently bound to lipid membranes, revealing that Nile red's (NR) orientation spectra are extremely sensitive to membrane chemical composition. SMOLM images resolve nanodomains and enzyme-induced compositional heterogeneity within membranes, where NR within liquid-ordered vs. liquid-disordered domains shows a ≈4° difference in polar angle and a ≈0.3π sr difference in wobble angle. As a new type of imaging spectroscopy, SMOLM exposes the organizational and functional dynamics of lipid-lipid, lipid-protein, and lipid-dye interactions with single-molecule, nanoscale resolution.
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Affiliation(s)
- Jin Lu
- Department of Electrical and Systems Engineering, Center for Science and Engineering of Living Systems, Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Hesam Mazidi
- Department of Electrical and Systems Engineering, Center for Science and Engineering of Living Systems, Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Tianben Ding
- Department of Electrical and Systems Engineering, Center for Science and Engineering of Living Systems, Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Oumeng Zhang
- Department of Electrical and Systems Engineering, Center for Science and Engineering of Living Systems, Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Matthew D Lew
- Department of Electrical and Systems Engineering, Center for Science and Engineering of Living Systems, Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
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36
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Lu J, Mazidi H, Ding T, Zhang O, Lew MD. Single‐Molecule 3D Orientation Imaging Reveals Nanoscale Compositional Heterogeneity in Lipid Membranes. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jin Lu
- Department of Electrical and Systems Engineering Center for Science and Engineering of Living Systems Institute of Materials Science and Engineering Washington University in St. Louis St. Louis MO 63130 USA
| | - Hesam Mazidi
- Department of Electrical and Systems Engineering Center for Science and Engineering of Living Systems Institute of Materials Science and Engineering Washington University in St. Louis St. Louis MO 63130 USA
| | - Tianben Ding
- Department of Electrical and Systems Engineering Center for Science and Engineering of Living Systems Institute of Materials Science and Engineering Washington University in St. Louis St. Louis MO 63130 USA
| | - Oumeng Zhang
- Department of Electrical and Systems Engineering Center for Science and Engineering of Living Systems Institute of Materials Science and Engineering Washington University in St. Louis St. Louis MO 63130 USA
| | - Matthew D. Lew
- Department of Electrical and Systems Engineering Center for Science and Engineering of Living Systems Institute of Materials Science and Engineering Washington University in St. Louis St. Louis MO 63130 USA
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37
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Fink L, Allolio C, Feitelson J, Tamburu C, Harries D, Raviv U. Bridges of Calcium Bicarbonate Tightly Couple Dipolar Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:10715-10724. [PMID: 32787004 PMCID: PMC7586406 DOI: 10.1021/acs.langmuir.0c01511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/02/2020] [Indexed: 06/11/2023]
Abstract
The interaction between lipid membranes and ions is associated with a range of key physiological processes. Most earlier studies have focused on the interaction of lipids with cations, while the specific effects of the anions have been largely overlooked. Owing to dissolved atmospheric carbon dioxide, bicarbonate is an important ubiquitous anion in aqueous media. In this paper, we report on the effect of bicarbonate anions on the interactions between dipolar lipid membranes in the presence of previously adsorbed calcium cations. Using a combination of solution X-ray scattering, osmotic stress, and molecular dynamics simulations, we followed the interactions between 1,2-didodecanoyl-sn-glycero-3-phosphocholine (DLPC) lipid membranes that were dialyzed against CaCl2 solutions in the presence and absence of bicarbonate anions. Calcium cations adsorbed onto DLPC membranes, charge them, and lead to their swelling. In the presence of bicarbonate anions, however, the calcium cations can tightly couple one dipolar DLPC membrane to the other and form a highly condensed and dehydrated lamellar phase with a repeat distance of 3.45 ± 0.02 nm. Similar tight condensation and dehydration has only been observed between charged membranes in the presence of multivalent counterions. Bridging between bilayers by calcium bicarbonate complexes induced this arrangement. Furthermore, in this condensed phase, lipid molecules and adsorbed ions were arranged in a two-dimensional oblique lattice.
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Affiliation(s)
- Lea Fink
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Christoph Allolio
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
- The
Fritz Haber Center, The Hebrew University
of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Jehuda Feitelson
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Carmen Tamburu
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Daniel Harries
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
- The
Fritz Haber Center, The Hebrew University
of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Uri Raviv
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
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38
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Direct and indirect cholesterol effects on membrane proteins with special focus on potassium channels. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158706. [DOI: 10.1016/j.bbalip.2020.158706] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/16/2022]
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39
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Engberg O, Lin KL, Hautala V, Slotte JP, Nyholm TKM. Sphingomyelin Acyl Chains Influence the Formation of Sphingomyelin- and Cholesterol-Enriched Domains. Biophys J 2020; 119:913-923. [PMID: 32755561 DOI: 10.1016/j.bpj.2020.07.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
The segregation of lipids into lateral membrane domains has been extensively studied. It is well established that the structural differences between phospholipids play an important role in lateral membrane organization. When a high enough cholesterol concentration is present in the bilayer, liquid-ordered (Lo) domains, which are enriched in cholesterol and saturated phospholipids such as sphingomyelin (SM), may form. We have recently shown that such a formation of domains can be facilitated by the affinity differences of cholesterol for the saturated and unsaturated phospholipids present in the bilayer. In mammalian membranes, the saturated phospholipids are usually SMs with different acyl chains, the abundance of which vary with cell type. In this study, we investigated how the acyl chain structure of SMs affects the formation of SM- and cholesterol-enriched domains. From the analysis of trans-parinaric acid fluorescence emission lifetimes, we could determine that cholesterol facilitated lateral segregation most with the SMs that had 16 carbon-long acyl chains. Using differential scanning calorimetry and Förster resonance energy transfer techniques, we observed that the SM- and cholesterol-enriched domains with 16 carbon-long SMs were most thermally stabilized by cholesterol. The Förster resonance energy transfer technique also suggested that the same SMs also form the largest Lo domains. In agreement with our previously published data, the extent of influence that cholesterol had on the propensity of lateral segregation and the properties of Lo domains correlated with the relative affinity of cholesterol for the phospholipids present in the bilayers. Therefore, the specific SM species present in the membranes, together with unsaturated phospholipids and cholesterol, can be used by the cell to fine-tune the lateral structure of the membranes.
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Affiliation(s)
- Oskar Engberg
- Biochemistry, Faculty of Science and Engineering, Abo Akademi University, Turku, Finland
| | - Kai-Lan Lin
- Biochemistry, Faculty of Science and Engineering, Abo Akademi University, Turku, Finland
| | - Victor Hautala
- Biochemistry, Faculty of Science and Engineering, Abo Akademi University, Turku, Finland
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Abo Akademi University, Turku, Finland
| | - Thomas K M Nyholm
- Biochemistry, Faculty of Science and Engineering, Abo Akademi University, Turku, Finland.
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40
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Aryal CM, Bui NN, Khadka NK, Song L, Pan J. The helix 0 of endophilin modifies membrane material properties and induces local curvature. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183397. [PMID: 32533976 DOI: 10.1016/j.bbamem.2020.183397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 11/26/2022]
Abstract
The amphipathic helix 0 of endophilin (i.e., H0-Endo) is important to membrane binding, but its function of curvature generation remains controversial. We used electron paramagnetic resonance (EPR) spectroscopy to study effects of H0-Endo on membrane material properties. We found that H0-Endo reduced lipid chain mobility and increased bilayer polarity, i.e., making the bilayer interior more polar. Lipid-dependent examination revealed that anionic lipids augmented the effect of H0-Endo, while cholesterol had a minimal impact. Our EPR spectroscopy of magnetically aligned bicelles showed that as the peptide-to-lipid ratio increased, the lipid chain orientational order decreased gradually, followed by a sudden loss. We discuss an interfacial-bound model of the amphipathic H0-Endo to account for all EPR data. We used atomic force microscopy and fluorescence microscopy to explore membrane morphological changes. We found that H0-Endo caused the formation of micron-sized holes in mica-supported planar bilayers. Hole formation is likely caused by two competing forces - the adhesion force exerted by the substrate represses bilayer budging, whereas the line tension originating from peptide clustering has a tendency of destabilizing bilayer organization. In the absence of substrate influences, membrane curvature induction was manifested by generating small vesicles surrounding giant unilamellar vesicles. Our results of membrane perforation and vesiculation suggest that the functionality of H0-Endo is more than just coordinating membrane binding of endophilin.
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Affiliation(s)
- Chinta M Aryal
- Department of Physics, University of South Florida, Tampa, FL 33620, United States of America
| | - Nhat Nguyen Bui
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States of America
| | - Nawal K Khadka
- Department of Physics, University of South Florida, Tampa, FL 33620, United States of America
| | - Likai Song
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States of America.
| | - Jianjun Pan
- Department of Physics, University of South Florida, Tampa, FL 33620, United States of America.
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41
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Hammons JA, Ingólfsson HI, Lee JRI, Carpenter TS, Sanborn J, Tunuguntla R, Yao YC, Weiss TM, Noy A, Van Buuren T. Decoupling copolymer, lipid and carbon nanotube interactions in hybrid, biomimetic vesicles. NANOSCALE 2020; 12:6545-6555. [PMID: 32159198 DOI: 10.1039/c9nr09973e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bilayer vesicles that mimic a real biological cell can be tailored to carry out a specific function by manipulating the molecular composition of the amphiphiles. These bio-inspired and bio-mimetic structures are increasingly being employed for a number of applications from drug delivery to water purification and beyond. Complex hybrid bilayers are the key building blocks for fully synthetic vesicles that can mimic biological cell membranes, which often contain a wide variety of molecular species. While the assembly and morpholgy of pure phospholid bilayer vesicles is well understood, the functionality and structure dramaticlly changes when copolymer and/or carbon nanotube porins (CNTP) are added. The aim of this study is to understand how the collective molecular interactions within hybrid vesicles affect their nanoscale structure and properties. In situ small and wide angle X-ray scattering (SAXS/WAXS) and molecular dynamics simulations (MD) are used to investigate the morphological effect of molecular interactions between polybutadiene polyethylene oxide, lipids and carbon nanotubes (CNT) within the hybrid vesicle bilayer. Within the lipid/copolymer system, the hybrid bilayer morphology transitions from phase separated lipid and compressed copolymer at low copolymer loadings to a mixed bilayer where opposing lipids are mostly separated from the inner region. This transition begins between 60 wt% and 70 wt%, with full homogenization observed by 80 wt% copolymer. The incorporation of CNT into the hybrid vesicles increases the bilayer thickness and enhances the bilayer symmetry. Analysis of the WAXS and MD indicate that the CNT-dioleoyl interactions are much stronger than the CNT-polybutadiene.
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Affiliation(s)
- Joshua A Hammons
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, USA.
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42
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Kheyfets B, Mukhin S, Galimzyanov T. Origin of lipid tilt in flat monolayers and bilayers. Phys Rev E 2020; 100:062405. [PMID: 31962538 DOI: 10.1103/physreve.100.062405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Indexed: 11/07/2022]
Abstract
This paper continues the series of our works devoted to the liquid-gel phase transition in lipid membranes. Previously we described a variation of area per lipid, membrane thickness, and diffusion coefficient at the temperature-driven liquid-gel phase transition in bilayers. Here we expand the application of our analytic model approach to include a description of the lipid tilt and also extend the investigation to include Langmuir and self-assembled monolayers. The theory describes tilt formation at the temperature-driven liquid-gel phase transition in bilayers and the pressure-driven phase transition in Langmuir monolayers. Neither uniform tilt nor liquid-gel phase transition is found in self-assembled monolayers chemically bonded to the substrate.
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Affiliation(s)
- Boris Kheyfets
- National University of Science and Technology MISIS, Leninskiy Prospekt, 4, Moscow 119049, Russia
| | | | - Timur Galimzyanov
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS and National University of Science and Technology MISIS, Leninskiy Prospekt, 4, Moscow 119049, Russia
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43
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Tyler AII, Greenfield JL, Seddon JM, Brooks NJ, Purushothaman S. Coupling Phase Behavior of Fatty Acid Containing Membranes to Membrane Bio-Mechanics. Front Cell Dev Biol 2019; 7:187. [PMID: 31616666 PMCID: PMC6763698 DOI: 10.3389/fcell.2019.00187] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 08/22/2019] [Indexed: 12/15/2022] Open
Abstract
Biological membranes constantly modulate their fluidity for proper functioning of the cell. Modulation of membrane properties via regulation of fatty acid composition has gained a renewed interest owing to its relevance in endocytosis, endoplasmic reticulum membrane homeostasis, and adaptation mechanisms in the deep sea. Endowed with significant degrees of freedom, the presence of free fatty acids can alter the curvature of membranes which in turn can alter the response of curvature sensing proteins, thus defining adaptive ways to reconfigure membranes. Most significantly, recent experiments demonstrated that polyunsaturated lipids facilitate membrane bending and fission by endocytic proteins – the first step in the biogenesis of synaptic vesicles. Despite the vital roles of fatty acids, a systematic study relating the interactions between fatty acids and membrane and the consequent effect on the bio-mechanics of membranes under the influence of fatty acids has been sparse. Of specific interest is the vast disparity in the properties of cis and trans fatty acids, that only differ in the orientation of the double bond and yet have entirely unique and opposing chemical properties. Here we demonstrate a combined X-ray diffraction and membrane fluctuation analysis method to couple the structural properties to the biophysical properties of fatty acid-laden membranes to address current gaps in our understanding. By systematically doping pure dioleoyl phosphatidylcholine (DOPC) membranes with cis fatty acid and trans fatty acid we demonstrate that the presence of fatty acids doesn’t always fluidize the membrane. Rather, an intricate balance between the curvature, molecular interactions, as well as the amount of specific fatty acid dictates the fluidity of membranes. Lower concentrations are dominated by the nature of interactions between the phospholipid and the fatty acids. Trans fatty acid increases the rigidity while decreasing the area per lipid similar to the properties depicted by the addition of saturated fatty acids to lipidic membranes. Cis fatty acid however displays the accepted view of having a fluidizing effect at small concentrations. At higher concentrations curvature frustration dominates, leading to increased rigidity irrespective of the type of fatty acid. These results are consistent with theoretical predictions as detailed in the manuscript.
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Affiliation(s)
- Arwen I I Tyler
- Department of Chemistry, Imperial College London, London, United Kingdom.,School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom
| | - Jake L Greenfield
- Department of Chemistry, Imperial College London, London, United Kingdom.,Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - John M Seddon
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Nicholas J Brooks
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Sowmya Purushothaman
- Department of Material Science, University of California, Davis, Davis, CA, United States.,Cavendish Laboratory, Cambridge, United Kingdom
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44
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Golysheva EA, Dzuba SA. Lipid chain mobility and packing in DOPC bilayers at cryogenic temperatures. Chem Phys Lipids 2019; 226:104817. [PMID: 31525380 DOI: 10.1016/j.chemphyslip.2019.104817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/07/2019] [Accepted: 09/03/2019] [Indexed: 11/30/2022]
Abstract
Low-temperature molecular mobility and packing in biological tissues are important for their survival upon cryopreservation. Electron paramagnetic resonance (EPR) in its pulsed version of electron spin echo (ESE) allows studying stochastic librations of spin-labeled molecules, the type of motion which dominates at low temperatures. These librations are characterized by the parameter <α2>τc where <α2> is the mean squared angular amplitude and τc is the correlation time for the motion. This parameter is known to be larger for higher temperature and for looser intermolecular structure. In this work, ESE data for the bilayers comprised of doubly-unsaturated DOPC (dioleoyl-glycero-phosphocholine) lipids and mono-unsaturated POPC (palmitoyl-oleoyl-glycero-phosphocholine) lipids with spin-labeled stearic acids added were obtained in the temperature range between 80 and 210 K; the results were compared also with the previously obtained data for fully-saturated DPPC (dipalmitoyl-glycero-phosphocholine) lipid bilayers [J. Phys. Chem. B2014, 118, 12,478-12,485; Appl. Magn. Reson. 2018, 49, 1369-1383]. It turned out that for DOPC bilayers the <α2>τc values are of intermediate magnitude between those for POPC and DPPC bilayers, which implies an intermediate density of lipid packing. A possible explanation of this result could be rearrangement at cryogenic temperatures of the DOPC lipid tails, with their terminal segments folding cooperatively. This interpretation is also in agreement with the known thermodynamic properties of gel-fluid transition for DOPC bilayer.
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Affiliation(s)
- Elena A Golysheva
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, 630090, Russian Federation; Department of Physics, Novosibirsk State University, Novosibirsk, 630090, Russian Federation
| | - Sergei A Dzuba
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, 630090, Russian Federation; Department of Physics, Novosibirsk State University, Novosibirsk, 630090, Russian Federation.
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45
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Enoki TA, Feigenson GW. Asymmetric Bilayers by Hemifusion: Method and Leaflet Behaviors. Biophys J 2019; 117:1037-1050. [PMID: 31493862 DOI: 10.1016/j.bpj.2019.07.054] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/13/2019] [Accepted: 07/08/2019] [Indexed: 01/03/2023] Open
Abstract
We describe a new method to prepare asymmetric giant unilamellar vesicles (aGUVs) via hemifusion. Hemifusion of giant unilamellar vesicles and a supported lipid bilayer, triggered by calcium, promotes the lipid exchange of the fused outer leaflets mediated by lipid diffusion. We used different fluorescent dyes to monitor the inner and the outer leaflets of the unsupported aGUVs. We confirmed that almost all newly exchanged lipids in the aGUVs are found in the outer leaflet of these asymmetric vesicles. In addition, we test the stability of the aGUVs formed by hemifusion in preserving their contents during the procedure. For aGUVs prepared from the hemifusion of giant unilamellar vesicles composed of 1,2-distearoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-phosphocholine/cholesterol = 0.39/0.39/0.22 and a supported lipid bilayer of 1,2-dioleoyl-sn-glycero-3-phosphocholine/cholesterol = 0.8/0.2, we observed the exchanged lipids to alter the bilayer properties. To access the physical and chemical properties of the asymmetric bilayer, we monitored the dye partition coefficients of individual leaflets and the generalized polarization of the fluorescence probe 6-dodecanoyl-2-[ N-methyl-N-(carboxymethyl)amino] naphthalene, a sensor for the lipid packing/order of its surroundings. For a high percentage of lipid exchange (>70%), the dye partition indicates induced-disordered and induced-ordered domains. The induced domains have distinct lipid packing/order compared to the symmetric liquid-disordered and liquid-ordered domains.
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Affiliation(s)
- Thais A Enoki
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York.
| | - Gerald W Feigenson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
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46
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Raggi C, Diociaiuti M, Caracciolo G, Fratini F, Fantozzi L, Piccaro G, Fecchi K, Pizzi E, Marano G, Ciaffoni F, Bravo E, Fiani ML, Sargiacomo M. Caveolin-1 Endows Order in Cholesterol-Rich Detergent Resistant Membranes. Biomolecules 2019; 9:biom9070287. [PMID: 31319608 PMCID: PMC6680987 DOI: 10.3390/biom9070287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/27/2019] [Accepted: 07/14/2019] [Indexed: 01/14/2023] Open
Abstract
Cholesterol-enriched functional portions of plasma membranes, such as caveolae and rafts, were isolated from lungs of wild-type (WT) and caveolin-1 knockout (Cav-1 KO) mice within detergent resistant membranes (DRMs). To gain insight into their molecular composition we performed proteomic and lipid analysis on WT and Cav-1 KO-DRMs that showed predicted variations of proteomic profiles and negligible differences in lipid composition, while Langmuir monolayer technique and small and wide-angle X-ray scattering (SAXS-WAXS) were here originally introduced to study DRMs biophysical association state. Langmuir analysis of Cav-1 containing DRMs displayed an isotherm with a clear-cut feature, suggesting the coexistence of the liquid-ordered (Lo) phase typical of the raft structure, namely “cholesterol-rich Lo phase”, with a phase fully missing in Cav-1 KO that we named “caveolin-induced Lo phase”. Furthermore, while the sole lipid component of both WT and KO-DRMs showed qualitatively similar isotherm configuration, the reinsertion of recombinant Cav-1 into WT-DRMs lipids restored the WT-DRM pattern. X-ray diffraction results confirmed that Cav-1 causes the formation of a “caveolin-induced Lo phase”, as suggested by Langmuir experiments, allowing us to speculate about a possible structural model. These results show that the unique molecular link between Cav-1 and cholesterol can spur functional order in a lipid bilayer strictly derived from biological sources.
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Affiliation(s)
- Carla Raggi
- National Center for Control and Evaluation of Medicines, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Marco Diociaiuti
- National Center for Rare Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Giulio Caracciolo
- Department of Molecular Medicine, "La Sapienza" University, 00161 Rome, Italy
| | - Federica Fratini
- Scientific Service for Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Luca Fantozzi
- Present address : ARPALAZIO, Via Salaria per L'Aquila 6/8, 02100 Rieti, Italy
| | | | - Katia Fecchi
- Reference Centre for Gender Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Elisabetta Pizzi
- Scientific Service for Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Giuseppe Marano
- Reference Centre for Gender Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Fiorella Ciaffoni
- Scientific Service for Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Elena Bravo
- Scientific Service for Research Coordination and Support, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Maria L Fiani
- National Center for Global Health, Istituto Superiore di Sanità, 00161 Rome, Italy.
| | - Massimo Sargiacomo
- National Center for Global Health, Istituto Superiore di Sanità, 00161 Rome, Italy.
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47
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Enoki TA, Heberle FA, Feigenson GW. FRET Detects the Size of Nanodomains for Coexisting Liquid-Disordered and Liquid-Ordered Phases. Biophys J 2019; 114:1921-1935. [PMID: 29694869 DOI: 10.1016/j.bpj.2018.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 02/15/2018] [Accepted: 03/15/2018] [Indexed: 11/18/2022] Open
Abstract
Biomembranes with as few as three lipid components can form coexisting liquid-disordered (Ld) and liquid-ordered (Lo) phases. In the coexistence region of Ld and Lo phases, the lipid mixtures 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/chol or brain sphingomyelin (bSM)/DOPC/chol form micron-scale domains that are easily visualized with light microscopy. Although large domains are not observed in the mixtures DSPC/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/chol and bSM/POPC/chol, lateral heterogeneity is nevertheless detected using techniques with nanometer-scale spatial resolution. We propose a simple and accessible method to measure domain sizes below optical resolution (∼200 nm). We measured nanodomain size for the latter two mixtures by combining experimental Förster resonance energy transfer data with a Monte-Carlo-based analysis. We found a domain radius of 7.5-10 nm for DSPC/POPC/chol, similar to values obtained previously by neutron scattering, and ∼5 nm for bSM/POPC/chol, slightly smaller than measurable by neutron scattering. These analyses also detect the domain-size transition that is observed by fluorescence microscopy in the four-component lipid mixture bSM/DOPC/POPC/chol. Accurate measurements of fluorescent-probe partition coefficients are especially important for the analysis; therefore, we exploit three different methods to measure the partition coefficient of fluorescent molecules between Ld and Lo phases.
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Affiliation(s)
- Thais A Enoki
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Frederick A Heberle
- Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Large Scale Structures Group, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Gerald W Feigenson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York.
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48
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Khondker A, Hub JS, Rheinstädter MC. Steroid-steroid interactions in biological membranes: Cholesterol and cortisone. Chem Phys Lipids 2019; 221:193-197. [PMID: 30951711 DOI: 10.1016/j.chemphyslip.2019.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 11/17/2022]
Abstract
Steroid flares are common side effects associated with corticosteroid treatment, and have been recently theorized to be a consequence of drug crystallization. It was previously reported that the lipid bilayer can promote crystallization of cortisone at high local concentrations. Here, we studied the effect of cholesterol on this membrane induced cortisone crystallization. By combining x-ray diffraction and Molecular Dynamics simulations we observe that that the presence of cholesterol suppresses cortisone-induced membrane thinning and cortisone transnucleation. Cortisone located in the head-tail interface of the membranes also in the presence of cholesterol. The cholesterol molecules were found to be tilted and displaced towards the bilayer center as function of cortisone concentration, away from their canonical position. Our results show that membrane cholesterol may play an important role in the ability of lipid bilayers to catalyze the formation of corticosteroid crystallites.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jochen S Hub
- Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken, Germany
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada.
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49
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Pak A, Dannenhoffer-Lafage T, Madsen JJ, Voth GA. Systematic Coarse-Grained Lipid Force Fields with Semiexplicit Solvation via Virtual Sites. J Chem Theory Comput 2019; 15:2087-2100. [PMID: 30702887 PMCID: PMC6416712 DOI: 10.1021/acs.jctc.8b01033] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Indexed: 12/15/2022]
Abstract
Despite the central role of lipids in many biophysical functions, the molecular mechanisms that dictate macroscopic lipid behavior remain elusive to both experimental and computational approaches. As such, there has been much interest in the development of low-resolution, implicit-solvent coarse-grained (CG) models to dynamically simulate biologically relevant spatiotemporal scales with molecular fidelity. However, in the absence of solvent, a key challenge for CG models is to faithfully emulate solvent-mediated forces, which include both hydrophilic and hydrophobic interactions that drive lipid aggregation and self-assembly. In this work, we provide a new methodological framework to incorporate semiexplicit solvent effects through the use of virtual CG particles, which represent structural features of the solvent-lipid interface. To do so, we leverage two systematic coarse-graining approaches, multiscale coarse-graining (MS-CG) and relative entropy minimization (REM), in a hybrid fashion to construct our virtual-site CG (VCG) models. As a proof-of-concept, we focus our efforts on two lipid species, 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC), which adopt a liquid-disordered and gel phase, respectively, at room temperature. Through our analysis, we also present, to our knowledge, the first direct comparison between the MS-CG and REM methods for a complex biomolecule and highlight each of their strengths and weaknesses. We further demonstrate that VCG models recapitulate the rich biophysics of lipids, which enable self-assembly, morphological diversity, and multiple phases. Our findings suggest that the VCG framework is a powerful approach for investigation into macromolecular biophysics.
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Affiliation(s)
- Alexander
J. Pak
- Department of Chemistry, The
University of Chicago, Chicago, Illinois 60637, United States
| | | | - Jesper J. Madsen
- Department of Chemistry, The
University of Chicago, Chicago, Illinois 60637, United States
| | - Gregory A. Voth
- Department of Chemistry, The
University of Chicago, Chicago, Illinois 60637, United States
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50
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Shahane G, Ding W, Palaiokostas M, Orsi M. Physical properties of model biological lipid bilayers: insights from all-atom molecular dynamics simulations. J Mol Model 2019; 25:76. [PMID: 30806797 DOI: 10.1007/s00894-019-3964-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/07/2019] [Indexed: 02/04/2023]
Abstract
The physical properties of lipid bilayers are sensitive to the specific type and composition of the lipids that make up the many different types of cell membranes. Studying model bilayers of representative heterogeneous compositions can provide key insights into membrane functionality. In this work, we use atomistic molecular dynamics simulations to characterize key properties in a number of bilayer membranes of varying composition. We first examine basic properties, such as lipid area, volume, and bilayer thickness, of simple, homogeneous bilayers comprising several lipid types, which are prevalent in biological membranes. Such lipids are then used in simulations of heterogeneous systems representative of bacterial, mammalian, and cancer membranes. Our analysis is especially focused on depth-dependent, transmembrane profiles; in particular, we calculate lateral pressure and dipole potential profiles, two fundamental properties which play key roles in a large number of biological functions.
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Affiliation(s)
- Ganesh Shahane
- Institute of Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Wei Ding
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Michail Palaiokostas
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mario Orsi
- Department of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK.
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