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Remodeling of the Plasma Membrane by Surface-Bound Protein Monomers and Oligomers: The Critical Role of Intrinsically Disordered Regions. J Membr Biol 2022; 255:651-663. [PMID: 35930019 PMCID: PMC9718270 DOI: 10.1007/s00232-022-00256-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/07/2022] [Indexed: 12/24/2022]
Abstract
The plasma membrane (PM) of cells is a dynamic structure whose morphology and composition is in constant flux. PM morphologic changes are particularly relevant for the assembly and disassembly of signaling platforms involving surface-bound signaling proteins, as well as for many other mechanochemical processes that occur at the PM surface. Surface-bound membrane proteins (SBMP) require efficient association with the PM for their function, which is often achieved by the coordinated interactions of intrinsically disordered regions (IDRs) and globular domains with membrane lipids. This review focuses on the role of IDR-containing SBMPs in remodeling the composition and curvature of the PM. The ability of IDR-bearing SBMPs to remodel the Gaussian and mean curvature energies of the PM is intimately linked to their ability to sort subsets of phospholipids into nanoclusters. We therefore discuss how IDRs of many SBMPs encode lipid-binding specificity or facilitate cluster formation, both of which increase their membrane remodeling capacity, and how SBMP oligomers alter membrane shape by monolayer surface area expansion and molecular crowding.
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2
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Belessiotis-Richards A, Higgins SG, Sansom MSP, Alexander-Katz A, Stevens MM. Coarse-Grained Simulations Suggest the Epsin N-Terminal Homology Domain Can Sense Membrane Curvature without Its Terminal Amphipathic Helix. ACS NANO 2020; 14:16919-16928. [PMID: 33300799 PMCID: PMC7760104 DOI: 10.1021/acsnano.0c05960] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Nanoscale membrane curvature is a common feature in cell biology required for functions such as endocytosis, exocytosis and cell migration. These processes require the cytoskeleton to exert forces on the membrane to deform it. Cytosolic proteins contain specific motifs which bind to the membrane, connecting it to the internal cytoskeletal machinery. These motifs often bind charged phosphatidylinositol phosphate lipids present in the cell membrane which play significant roles in signaling. These lipids are important for membrane deforming processes, such as endocytosis, but much remains unknown about their role in the sensing of membrane nanocurvature by protein domains. Using coarse-grained molecular dynamics simulations, we investigated the interaction of a model curvature active protein domain, the epsin N-terminal homology domain (ENTH), with curved lipid membranes. The combination of anionic lipids (phosphatidylinositol 4,5-bisphosphate and phosphatidylserine) within the membrane, protein backbone flexibility, and structural changes within the domain were found to affect the domain's ability to sense, bind, and localize with nanoscale precision at curved membrane regions. The findings suggest that the ENTH domain can sense membrane curvature without the presence of its terminal amphipathic α helix via another structural region we have denoted as H3, re-emphasizing the critical relationship between nanoscale membrane curvature and protein function.
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Affiliation(s)
- Alexis Belessiotis-Richards
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
| | - Stuart G. Higgins
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
| | - Mark S. P. Sansom
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Alfredo Alexander-Katz
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Molly M. Stevens
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
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3
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Seyrig C, Kignelman G, Thielemans W, Le Griel P, Cowieson N, Perez J, Baccile N. Stimuli-Induced Nonequilibrium Phase Transitions in Polyelectrolyte-Surfactant Complex Coacervates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8839-8857. [PMID: 32702994 DOI: 10.1021/acs.langmuir.0c01177] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Polyelectrolyte-surfactant complexes (PESCs) are important soft colloids with applications in the fields of personal care, cosmetics, pharmaceutics, and much more. If their phase diagrams have long been studied under pseudoequilibrium conditions, and often inside the micellar or vesicular regions, understanding the effect of nonequilibrium conditions, applied at phase boundaries, on the structure of PESCs generates an increasing interest. In this work we cross the micelle-vesicle and micelle-fiber phase boundaries in an isocompositional surfactant-polyelectrolyte aqueous system through a continuous and rapid variation of pH. We employ two microbial glycolipid biosurfactants in the presence of polyamines, both systems being characterized by their responsiveness to pH. We show that complex coacervates (Co) are always formed in the micellar region of both glycolipids' phase diagram and that their phase behavior drives the PESC stability and structure. However, for glycolipid forming single-wall vesicles, we observe an isostructural and isodimensional transition between complex coacervates and a multilamellar walls vesicle (MLWV) phase. For the fiber-forming glycolipid, on the contrary, the complex coacervate disassembles into free polyelectrolyte coexisting with the equilibrium fiber phase. Last but not least, this work also demonstrates the use of microbial glycolipid biosurfactants in the development of sustainable PESCs.
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Affiliation(s)
- Chloé Seyrig
- Sorbonne Université, Centre National de la Recherche Scientifique, Laboratoire de Chimie de la Matière Condensée de Paris, LCMCP, F-75005 Paris, France
| | - Gertrude Kignelman
- Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
| | - Wim Thielemans
- Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
| | - Patrick Le Griel
- Sorbonne Université, Centre National de la Recherche Scientifique, Laboratoire de Chimie de la Matière Condensée de Paris, LCMCP, F-75005 Paris, France
| | - Nathan Cowieson
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom
| | - Javier Perez
- SWING, Synchrotron Soleil, BP 48, 91192 Gif-sur-Yvette, France
| | - Niki Baccile
- Sorbonne Université, Centre National de la Recherche Scientifique, Laboratoire de Chimie de la Matière Condensée de Paris, LCMCP, F-75005 Paris, France
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4
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Masuda T, Hirose H, Baba K, Walrant A, Sagan S, Inagaki N, Fujimoto T, Futaki S. An Artificial Amphiphilic Peptide Promotes Endocytic Uptake by Inducing Membrane Curvature. Bioconjug Chem 2020; 31:1611-1615. [DOI: 10.1021/acs.bioconjchem.0c00239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Toshihiro Masuda
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hisaaki Hirose
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kentarou Baba
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Astrid Walrant
- Sorbonne Université, École Normale Supérieure,
PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005 Paris, France
| | - Sandrine Sagan
- Sorbonne Université, École Normale Supérieure,
PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005 Paris, France
| | - Naoyuki Inagaki
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Toyoshi Fujimoto
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, 113-8421 Tokyo, Japan
| | - Shiroh Futaki
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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5
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Shimokawa N, Ito H, Higuchi Y. Coarse-grained molecular dynamics simulation for uptake of nanoparticles into a charged lipid vesicle dominated by electrostatic interactions. Phys Rev E 2019; 100:012407. [PMID: 31499808 DOI: 10.1103/physreve.100.012407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Indexed: 06/10/2023]
Abstract
We use a coarse-grained molecular dynamics simulation to investigate the interaction between neutral or charged nanoparticles (NPs) and a vesicle consisting of neutral and negatively charged lipids. We focus on the interaction strengths of hydrophilic and hydrophobic attraction and electrostatic interactions between a lipid molecule and an NP. A neutral NP passes through the lipid membrane when the hydrophobic interaction is sufficiently strong. As the valence of the positively charged NP increases, the membrane permeation speed of the NP is increased compared with the neutral NP and charged lipids are accumulated around the charged NP. A charged NP with a high valence passes through the lipid membrane via a transient channel formed by charged lipids or transportlike endocytosis. These permeation processes can be classified based on analyses of the density correlation function. When the nonelectrostatic interaction parameters are large enough, a negatively charged NP can be adsorbed on the membrane and a neutral lipid-rich region is formed directly below the NP. The NP is spontaneously incorporated into the vesicle under various conditions and the incorporation is mediated by the membrane curvature. We reveal how the NP's behavior depends on the NP valence, size, and the nonelectrostatic interaction parameters.
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Affiliation(s)
- Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Hiroaki Ito
- Department of Mechanical Engineering, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Yuji Higuchi
- Institute for Solid State Physics, University of Tokyo, Chiba 227-8581, Japan
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6
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Bassereau P, Jin R, Baumgart T, Deserno M, Dimova R, Frolov VA, Bashkirov PV, Grubmüller H, Jahn R, Risselada HJ, Johannes L, Kozlov MM, Lipowsky R, Pucadyil TJ, Zeno WF, Stachowiak JC, Stamou D, Breuer A, Lauritsen L, Simon C, Sykes C, Voth GA, Weikl TR. The 2018 biomembrane curvature and remodeling roadmap. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2018; 51:343001. [PMID: 30655651 PMCID: PMC6333427 DOI: 10.1088/1361-6463/aacb98] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The importance of curvature as a structural feature of biological membranes has been recognized for many years and has fascinated scientists from a wide range of different backgrounds. On the one hand, changes in membrane morphology are involved in a plethora of phenomena involving the plasma membrane of eukaryotic cells, including endo- and exocytosis, phagocytosis and filopodia formation. On the other hand, a multitude of intracellular processes at the level of organelles rely on generation, modulation, and maintenance of membrane curvature to maintain the organelle shape and functionality. The contribution of biophysicists and biologists is essential for shedding light on the mechanistic understanding and quantification of these processes. Given the vast complexity of phenomena and mechanisms involved in the coupling between membrane shape and function, it is not always clear in what direction to advance to eventually arrive at an exhaustive understanding of this important research area. The 2018 Biomembrane Curvature and Remodeling Roadmap of Journal of Physics D: Applied Physics addresses this need for clarity and is intended to provide guidance both for students who have just entered the field as well as established scientists who would like to improve their orientation within this fascinating area.
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Affiliation(s)
- Patricia Bassereau
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | - Rui Jin
- Chemistry Department, University of Pennsylvania, Philadelphia, PA 19104-6323, United States of America
| | - Tobias Baumgart
- Chemistry Department, University of Pennsylvania, Philadelphia, PA 19104-6323, United States of America
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Rumiana Dimova
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | - Vadim A Frolov
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Leioa 48940, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48013, Spain
| | - Pavel V Bashkirov
- Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow 119435, Russia
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow 119071, Russia
| | - Helmut Grubmüller
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - H Jelger Risselada
- Department of Theoretical Physics, Georg-August University, Göttingen, Germany
| | - Ludger Johannes
- Cellular and Chemical Biology Unit, Institut Curie, PSL Research University, U1143 INSERM, UMR3666 CNRS, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Michael M Kozlov
- Sackler Faculty of Medicine, Department of Physiology and Pharmacology, Tel Aviv University
| | - Reinhard Lipowsky
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | | | - Wade F Zeno
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, United States of America
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, United States of America
- University of Texas at Austin, Institute for Cellular and Molecular Biology, Austin, TX, United States of America
| | - Dimitrios Stamou
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, Nano-Science Center, University of Copenhagen, Denmark
| | - Artú Breuer
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, Nano-Science Center, University of Copenhagen, Denmark
| | - Line Lauritsen
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, Nano-Science Center, University of Copenhagen, Denmark
| | - Camille Simon
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | - Cécile Sykes
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, United States of America
| | - Thomas R Weikl
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
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7
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Aydin F, Dutt M. Surface Reconfiguration of Binary Lipid Vesicles via Electrostatically Induced Nanoparticle Adsorption. J Phys Chem B 2016; 120:6646-56. [DOI: 10.1021/acs.jpcb.6b02334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Fikret Aydin
- Department
of Chemical and
Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Meenakshi Dutt
- Department
of Chemical and
Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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8
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Spangler EJ, Upreti S, Laradji M. Partial wrapping and spontaneous endocytosis of spherical nanoparticles by tensionless lipid membranes. J Chem Phys 2016; 144:044901. [PMID: 26827231 PMCID: PMC4723410 DOI: 10.1063/1.4939764] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/25/2015] [Indexed: 12/25/2022] Open
Abstract
Computer simulations of an implicit-solvent particle-based model are performed to investigate the interactions between small spherical nanoparticles and tensionless lipid bilayers. We found that nanoparticles are either unbound, wrapped by the bilayer, or endocytosed. The degree of wrapping increases with increasing the adhesion strength. The transition adhesion strength between the unbound and partially wrapped states decreases as the nanoparticle diameter is increased. We also observed that the transition adhesion strength between the wrapped states and endocytosis state decreases with increasing the nanoparticle diameter. The partial wrapping of the nanoparticles by the tensionless bilayer is explained by an elastic theory which accounts for the fact that the interaction between the nanoparticle and the bilayer extends beyond the contact region. The theory predicts that for small nanoparticles, the wrapping angle increases continuously with increasing the adhesion strength. However, for relatively large nanoparticles, the wrapping angle exhibits a discontinuity between weakly and strongly wrapped states. The size of the gap in the wrapping angle between the weakly wrapped and strongly wrapped states increases with decreasing the range of nanoparticle-bilayer interaction.
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Affiliation(s)
- Eric J Spangler
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee 38152, USA
| | - Sudhir Upreti
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, USA
| | - Mohamed Laradji
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, USA
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9
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Ben-Yaakov D, Andelman D, Podgornik R, Harries D. Ion-specific hydration effects: Extending the Poisson-Boltzmann theory. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.04.012] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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10
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Translocation of HIV TAT peptide and analogues induced by multiplexed membrane and cytoskeletal interactions. Proc Natl Acad Sci U S A 2011; 108:16883-8. [PMID: 21969533 DOI: 10.1073/pnas.1108795108] [Citation(s) in RCA: 258] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cell-penetrating peptides (CPPs), such as the HIV TAT peptide, are able to translocate across cellular membranes efficiently. A number of mechanisms, from direct entry to various endocytotic mechanisms (both receptor independent and receptor dependent), have been observed but how these specific amino acid sequences accomplish these effects is unknown. We show how CPP sequences can multiplex interactions with the membrane, the actin cytoskeleton, and cell-surface receptors to facilitate different translocation pathways under different conditions. Using "nunchuck" CPPs, we demonstrate that CPPs permeabilize membranes by generating topologically active saddle-splay ("negative Gaussian") membrane curvature through multidentate hydrogen bonding of lipid head groups. This requirement for negative Gaussian curvature constrains but underdetermines the amino acid content of CPPs. We observe that in most CPP sequences decreasing arginine content is offset by a simultaneous increase in lysine and hydrophobic content. Moreover, by densely organizing cationic residues while satisfying the above constraint, TAT peptide is able to combine cytoskeletal remodeling activity with membrane translocation activity. We show that the TAT peptide can induce structural changes reminiscent of macropinocytosis in actin-encapsulated giant vesicles without receptors.
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11
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Li Y, Gu N. Thermodynamics of Charged Nanoparticle Adsorption on Charge-Neutral Membranes: A Simulation Study. J Phys Chem B 2010; 114:2749-54. [DOI: 10.1021/jp904550b] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yang Li
- State Key Laboratory of Bioelectronics and Jiangsu Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, P. R. China
| | - Ning Gu
- State Key Laboratory of Bioelectronics and Jiangsu Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, P. R. China
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12
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Fošnarič M, Iglič A, Kroll DM, May S. Monte Carlo simulations of complex formation between a mixed fluid vesicle and a charged colloid. J Chem Phys 2009. [DOI: 10.1063/1.3191782] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Raviv U, Needleman DJ, Safinya CR. Cationic membranes complexed with oppositely charged microtubules: hierarchical self-assembly leading to bio-nanotubes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:S1271-S1279. [PMID: 21690840 DOI: 10.1088/0953-8984/18/28/s10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The self-assembly of microtubules and charged membranes has been studied, using x-ray diffraction and electron microscopy. Polyelectrolyte lipid complexes usually form structures templated by the lipid phase, when the polyelectrolyte curvature is much larger than the membrane spontaneous curvature. When the polyelectrolyte curvature approaches the membrane spontaneous curvature, as in microtubules, two types of new structures emerge. Depending on the conditions, vesicles either adsorb onto the microtubule, forming a 'beads on a rod' structure, or coat the microtubule, which now forms the template. Tubulin oligomers then coat the external lipid layer, forming a lipid protein nanotube. The tubulin oligomer coverage at the external layer is determined by the membrane charge density. The energy barrier between the beads on a rod and the lipid-protein nanotube states depends on the membrane bending rigidity and membrane charge density. By controlling the lipid/tubulin stoichiometry we can switch between lipid-protein nanotubes with open ends to lipid-protein nanotubes with closed end with lipid cups. This forms the basis for controlled drug encapsulation and release.
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Affiliation(s)
- Uri Raviv
- Materials Department, University of California, Santa Barbara, CA 93106, USA. Physics Department, University of California, Santa Barbara, CA 93106, USA. Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA
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14
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Raviv U, Needleman DJ, Li Y, Miller HP, Wilson L, Safinya CR. Cationic liposome-microtubule complexes: pathways to the formation of two-state lipid-protein nanotubes with open or closed ends. Proc Natl Acad Sci U S A 2005; 102:11167-72. [PMID: 16055561 PMCID: PMC1183551 DOI: 10.1073/pnas.0502183102] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Indexed: 11/18/2022] Open
Abstract
Intermolecular interactions between charged membranes and biological polyelectrolytes, tuned by physical parameters, which include the membrane charge density and bending rigidity, the membrane spontaneous curvature, the biopolymer curvature, and the overall charge of the complex, lead to distinct structures and morphologies. The self-assembly of cationic liposome-microtubule (MT) complexes was studied, using synchrotron x-ray scattering and electron microscopy. Vesicles were found to either adsorb onto MTs, forming a "beads on a rod" structure, or undergo a wetting transition and coating the MT. Tubulin oligomers then coat the external lipid layer, forming a tunable lipid-protein nanotube. The beads on a rod structure is a kinetically trapped state. The energy barrier between the states depends on the membrane bending rigidity and charge density. By controlling the cationic lipid/tubulin stoichiometry it is possible to switch between two states of nanotubes with either open ends or closed ends with lipid caps, a process that forms the basis for controlled chemical and drug encapsulation and release.
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Affiliation(s)
- Uri Raviv
- Department of Materials, University of California, Santa Barbara, CA 93106, USA.
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15
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Liang H, Harries D, Wong GCL. Polymorphism of DNA-anionic liposome complexes reveals hierarchy of ion-mediated interactions. Proc Natl Acad Sci U S A 2005; 102:11173-8. [PMID: 16061807 PMCID: PMC1183553 DOI: 10.1073/pnas.0502416102] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Self-assembled DNA delivery systems based on anionic lipids (ALs) complexed with DNA mediated by divalent cations have been recently introduced as an alternative to cationic lipid-DNA complexes because of their low cytotoxicity. We investigate AL-DNA complexes induced by different cations by using synchrotron small angle x-ray scattering and confocal microscopy to show how different ion-mediated interactions are expressed in the self-assembled structures and phase behavior of AL-DNA complexes. The governing interactions in AL-DNA systems are complex: divalent ions can mediate strong attractions between different combinations of the components (such as DNA-DNA and membrane-membrane). Moreover, divalent cations can coordinate non-electrostatically with lipids and modify the resultant membrane structure. We find that at low membrane charge densities AL-DNA complexes organize into a lamellar structure of alternating DNA and membrane layers crosslinked by ions. At high membrane charge densities, a new phase with no analog in cationic lipid-DNA systems is observed: DNA is expelled from the complex, and a lamellar stack of membranes and intercalated ions is formed. For a subset of the ionic species, high ion concentrations generate an inverted hexagonal phase comprised of DNA strands wrapped by ion-coated lipid tubes. A simple theoretical model that takes into account the electrostatic and membrane elastic contributions to the free energy shows that this transition is consistent with an ion-induced change in the membrane spontaneous curvature, c0. Moreover, the crossover between the lamellar and inverted hexagonal phases occurs at a critical c0 that agrees well with experimental values.
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Affiliation(s)
- Hongjun Liang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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16
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González-Amezcua O, Hernández-Contreras M. Phase evolution of lamellar cationic lipid-DNA complex: Steric effect of an electrolyte. J Chem Phys 2004; 121:10742-7. [PMID: 15549959 DOI: 10.1063/1.1809597] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The complexation isotherms of DNA plus lipids of a symmetric lamellar cationic lipid-DNA system were determined within a mean field free energy. The free energy incorporates the ion's finite size of NaCl simple electrolyte in solution and makes use of known structure data on this complex. The results for the predicted isotherms are in qualitative agreement with the trends of the experimental data for this property.
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Affiliation(s)
- O González-Amezcua
- Departamento de Física, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, A.P. 14-740, México Distrito Federal, México
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