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Ito H, Shimokawa N, Higuchi Y. Lateral Transport of Domains in Anionic Lipid Bilayer Membranes under DC Electric Fields: A Coarse-Grained Molecular Dynamics Study. J Phys Chem B 2023; 127:8860-8868. [PMID: 37801068 DOI: 10.1021/acs.jpcb.3c04351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Dynamic lateral transport of lipids, proteins, and self-assembled structures in biomembranes plays a crucial role in diverse cellular processes. In this study, we perform coarse-grained molecular dynamics simulations on a vesicle composed of a binary mixture of neutral and anionic lipids to investigate the lateral transport of individual lipid molecules and the self-assembled lipid domains upon an applied direct current (DC) electric field. Under the potential force of the electric field, a phase-separated domain rich in anionic lipids is trapped in the opposite direction of the electric field. The subsequent reversal of the electric field induces unidirectional domain motion. During the domain motion, the domain size remains constant, but a considerable amount of the anionic lipids is exchanged between the anionic-lipid-rich domain and the surrounding bulk. While the speed of the domain motion (collective lipid motion) shows a significant positive correlation with the electric field strength, the exchange of anionic lipids between the domain and bulk (individual lipid motion) exhibits no clear correlation with the field strength. The mean velocity field of the lipids surrounding the domain displays a two-dimensional (2D) source dipole. We revealed that the balance between the potential force of the applied electric field and the quasi-2D hydrodynamic frictional force well explains the dependence of the domain motions on the electric field strengths. The present results provide insight into the hierarchical dynamic responses of self-assembled lipid domains to the applied electric field and contribute to controlling the lateral transportation of lipids and membrane inclusions.
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Affiliation(s)
- Hiroaki Ito
- Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Yuji Higuchi
- Research Institute for Information Technology, Kyushu University, Fukuoka 819-0395, Japan
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2
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Hosaka Y, Andelman D, Komura S. Pair dynamics of active force dipoles in an odd-viscous fluid. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:18. [PMID: 36947274 DOI: 10.1140/epje/s10189-023-00265-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
We discuss the lateral dynamics of two active force dipoles, which interact with each other via hydrodynamic interactions in a thin fluid layer that is active and chiral. The fluid layer is modeled as a two-dimensional (2D) compressible fluid with an odd viscosity, while the force dipole (representing an active protein or enzyme) induces a dipolar flow. Taking into account the momentum decay in the 2D fluid, we obtain analytically the mobility tensor that depends on the odd viscosity and includes nonreciprocal hydrodynamic interactions. We find that the particle pair shows spiral behavior due to the transverse flow induced by the odd viscosity. When the magnitude of the odd viscosity is large as compared with the shear viscosity, two types of oscillatory behaviors are seen. One of them can be understood as arising from closed orbits in dynamical systems, and its circular trajectories are determined by the ratio between the magnitude of the odd viscosity and the force dipole. In addition, the phase diagrams of the particle dipolar angles are obtained numerically. Our findings reveal that the nonreciprocal response leads to complex dynamics of active particles embedded in an active fluid with odd viscosity.
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Affiliation(s)
- Yuto Hosaka
- Max Planck Institute for Dynamics and Self-Organization (MPI DS), Am Faßberg 17, 37077, Göttingen, Germany
| | - David Andelman
- School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, 69978, Tel Aviv, Israel
| | - Shigeyuki Komura
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325001, Zhejiang, China.
- Oujiang Laboratory, Wenzhou, 325000, Zhejiang, China.
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo, 192-0397, Japan.
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3
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Hosaka Y, Komura S, Andelman D. Hydrodynamic lift of a two-dimensional liquid domain with odd viscosity. Phys Rev E 2021; 104:064613. [PMID: 35030884 DOI: 10.1103/physreve.104.064613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/12/2021] [Indexed: 11/07/2022]
Abstract
We discuss hydrodynamic forces acting on a two-dimensional liquid domain that moves laterally within a supported fluid membrane in the presence of odd viscosity. Since active rotating proteins can accumulate inside the domain, we focus on the difference in odd viscosity between the inside and outside of the domain. Taking into account the momentum leakage from a two-dimensional incompressible fluid to the underlying substrate, we analytically obtain the fluid flow induced by the lateral domain motion and calculate the drag and lift forces acting on the moving liquid domain. In contrast to the passive case without odd viscosity, the lateral lift arises in the active case only when the in and out odd viscosities are different. The in-out contrast in the odd viscosity leads to nonreciprocal hydrodynamic responses of an active liquid domain.
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Affiliation(s)
- Yuto Hosaka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Shigeyuki Komura
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China.,Oujiang Laboratory, Wenzhou, Zhejiang 325000, China
| | - David Andelman
- School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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4
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Hosaka Y, Komura S, Andelman D. Nonreciprocal response of a two-dimensional fluid with odd viscosity. Phys Rev E 2021; 103:042610. [PMID: 34005895 DOI: 10.1103/physreve.103.042610] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/16/2021] [Indexed: 11/07/2022]
Abstract
We discuss the linear hydrodynamic response of a two-dimensional active chiral compressible fluid with odd viscosity. The viscosity coefficient represents broken time-reversal and parity symmetries in the 2D fluid and characterizes the deviation of the system from a passive fluid. Taking into account the hydrodynamic coupling to the underlying bulk fluid, we obtain the odd viscosity-dependent mobility tensor, which is responsible for the nonreciprocal hydrodynamic response to a point force. Furthermore, we consider a finite-size disk moving laterally in the 2D fluid and demonstrate that the disk experiences a nondissipative lift force in addition to the dissipative drag one.
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Affiliation(s)
- Yuto Hosaka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Shigeyuki Komura
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - David Andelman
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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5
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Sorkin B, Diamant H. Persistent collective motion of a dispersing membrane domain. Biophys J 2021; 120:2030-2039. [PMID: 33744264 DOI: 10.1016/j.bpj.2021.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/23/2021] [Accepted: 03/12/2021] [Indexed: 11/27/2022] Open
Abstract
We study the Brownian motion of an assembly of mobile inclusions embedded in a fluid membrane. The motion includes the dispersal of the assembly, accompanied by the diffusion of its center of mass. Usually, the former process is much faster than the latter because the diffusion coefficient of the center of mass is inversely proportional to the number of particles. However, in the case of membrane inclusions, we find that the two processes occur on the same timescale, thus significantly prolonging the lifetime of the assembly as a collectively moving object. This effect is caused by the quasi-two-dimensional membrane flows, which couple the motions of even the most remote inclusions in the assembly. The same correlations also cause the diffusion coefficient of the center of mass to decay slowly with time, resulting in weak subdiffusion. We confirm our analytical results by Brownian dynamics simulations with flow-mediated correlations. The effect reported here should have implications for the stability of nanoscale membrane heterogeneities.
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Affiliation(s)
- Benjamin Sorkin
- Raymond and Beverly Sackler School of Chemistry, Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel
| | - Haim Diamant
- Raymond and Beverly Sackler School of Chemistry, Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel.
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6
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Li Z, Yang J, Hollingsworth JV, Zhao J. Lateral diffusion of single polymer molecules at interfaces between water and oil. RSC Adv 2020; 10:16565-16569. [PMID: 35498844 PMCID: PMC9052869 DOI: 10.1039/d0ra02630a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 04/14/2020] [Indexed: 11/21/2022] Open
Abstract
Lateral diffusion of polymer molecules at the interfaces between immiscible oil and water is investigated at the single molecular level. The interfaces between water and alkanes are chosen as the model systems and polyethylene oxide (PEO) is the model polymer. Fluorescence correlation spectroscopy is used to measure the interfacial diffusion of fluorescence-labeled PEO with its molecular weight ranging over more than an order of magnitude. It is discovered that the interfacial diffusion coefficient scales with the molecular weight by the exponent of -0.5. Detailed analysis shows that the PEO chain takes an ideal two-dimensional random coil conformation at these fluidic interfaces and the bigger contribution from water's hydrodynamic friction is discovered.
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Affiliation(s)
- Zhuo Li
- Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,University of Chinese Academy of Sciences Beijing 100049 China
| | - Jingfa Yang
- Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,University of Chinese Academy of Sciences Beijing 100049 China
| | | | - Jiang Zhao
- Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,University of Chinese Academy of Sciences Beijing 100049 China
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7
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Zarif M, Bowles RK. Mapping diffusivity of narrow channels into one dimension. Phys Rev E 2020; 101:012908. [PMID: 32069685 DOI: 10.1103/physreve.101.012908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Indexed: 06/10/2023]
Abstract
The diffusion of particles trapped in long narrow channels occurs predominantly in one dimension. Here, a molecular-dynamics simulation is used to study the inertial dynamics of two-dimensional hard disks confined to long, narrow, structureless channels with hard walls in the no-passing regime. We show that the diffusion coefficient obtained from the mean-squared displacement can be mapped onto the exact results for the diffusion of the strictly-one-dimensional hard rod system through an effective occupied volume fraction obtained from either the equation of state or a geometric projection of the particle interaction diameters.
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Affiliation(s)
- Mahdi Zarif
- Department of Physical and Computational Chemistry, Shahid Beheshti University, Tehran 19839-9411, Iran
| | - Richard K Bowles
- Department of Chemistry, University of Saskatchewan, Saskatoon, S7N 5C9, Canada
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8
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Sokolov Y, Diamant H. Permeability of immobile rings of membrane inclusions to in-plane flow. J Chem Phys 2019; 150:154901. [DOI: 10.1063/1.5086865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Yulia Sokolov
- Raymond and Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Haim Diamant
- Raymond and Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
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9
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Sokolov Y, Diamant H. Many-particle mobility and diffusion tensors for objects in viscous sheets. J Chem Phys 2018; 149:034901. [PMID: 30037264 DOI: 10.1063/1.5037061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We derive a mobility tensor for many cylindrical objects embedded in a viscous sheet. This tensor guarantees a positive dissipation rate for any configuration of particles and forces, analogous to the Rotne-Prager-Yamakawa tensor for spherical particles in a three-dimensional viscous fluid. We test our result for a ring of radially driven particles, demonstrating the positive-definite property at all particle densities. The derived tensor can be utilized in Brownian dynamics simulations with hydrodynamic interactions for such systems as proteins in biomembranes and inclusions in free-standing liquid films.
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Affiliation(s)
- Yulia Sokolov
- Raymond and Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Haim Diamant
- Raymond and Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
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10
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Ota Y, Hosaka Y, Yasuda K, Komura S. Three-disk microswimmer in a supported fluid membrane. Phys Rev E 2018; 97:052612. [PMID: 29906974 DOI: 10.1103/physreve.97.052612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Indexed: 06/08/2023]
Abstract
A model of three-disk micromachine swimming in a quasi-two-dimensional supported membrane is proposed. We calculate the average swimming velocity as a function of the disk size and the arm length. Due to the presence of the hydrodynamic screening length in the quasi-two-dimensional fluid, the geometric factor appearing in the average velocity exhibits three different asymptotic behaviors depending on the microswimmer size and the hydrodynamic screening length. This is in sharp contrast with a microswimmer in a three-dimensional bulk fluid that shows only a single scaling behavior. We also find that the maximum velocity is obtained when the disks are equal-sized, whereas it is minimized when the average arm lengths are identical. The intrinsic drag of the disks on the substrate does not alter the scaling behaviors of the geometric factor.
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Affiliation(s)
- Yui Ota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Yuto Hosaka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Kento Yasuda
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Shigeyuki Komura
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan
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11
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Hosaka Y, Yasuda K, Okamoto R, Komura S. Lateral diffusion induced by active proteins in a biomembrane. Phys Rev E 2017; 95:052407. [PMID: 28618510 DOI: 10.1103/physreve.95.052407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Indexed: 06/07/2023]
Abstract
We discuss the hydrodynamic collective effects due to active protein molecules that are immersed in lipid bilayer membranes and modeled as stochastic force dipoles. We specifically take into account the presence of the bulk solvent that surrounds the two-dimensional fluid membrane. Two membrane geometries are considered: the free membrane case and the confined membrane case. Using the generalized membrane mobility tensors, we estimate the active diffusion coefficient and the drift velocity as a function of the size of a diffusing object. The hydrodynamic screening lengths distinguish the two asymptotic regimes of these quantities. Furthermore, the competition between the thermal and nonthermal contributions in the total diffusion coefficient is characterized by two length scales corresponding to the two membrane geometries. These characteristic lengths describe the crossover between different asymptotic behaviors when they are larger than the hydrodynamic screening lengths.
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Affiliation(s)
- Yuto Hosaka
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Kento Yasuda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Ryuichi Okamoto
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Shigeyuki Komura
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
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12
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Glagoleva AA, Vasilevskaya VV, Khokhlov AR. Polymer globule with fractal properties caused by intramolecular nanostructuring and spatial constrains. SOFT MATTER 2016; 12:5138-5145. [PMID: 27198966 DOI: 10.1039/c6sm00747c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
By means of computer simulation, we studied macromolecules composed of N dumbbell amphiphilic monomer units with attractive pendant groups. In poor solvents, these macromolecules form spherical globules that are dense in the case of short chains (the gyration radius RG∼N(1/3)), or hollow inside and obey the RG∼N(1/2) law when the macromolecules are sufficiently long. Due to the specific intramolecular nanostructuring, the vesicle-like globules of long amphiphilic macromolecules posses some properties of fractal globules, by which they (i) could demonstrate the same scaling statistics for the entire macromolecule and for short subchains with m monomer units and (ii) possess a specific territorial structure. Within a narrow slit, the globule loses its inner cavity, takes a disk-like shape and scales as N(1/2) for much shorter macromolecules. However, the field of end-to-end distance r(m) ∼m(1/2) dependence for subchains becomes visibly smaller. The results obtained were compared with the homopolymer case.
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Affiliation(s)
- Anna A Glagoleva
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, 119991 Moscow, Russia.
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13
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Simulation of Individual Polymer Chains and Polymer Solutions with Smoothed Dissipative Particle Dynamics. FLUIDS 2016. [DOI: 10.3390/fluids1010007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Taddese T, Cheung DL, Carbone P. Scaling Behavior of Polymers at Liquid/Liquid Interfaces. ACS Macro Lett 2015; 4:1089-1093. [PMID: 35614809 DOI: 10.1021/acsmacrolett.5b00462] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dynamics of a polymer chain confined in a soft 2D slit formed by two immiscible liquids is studied by means of molecular dynamics simulations. We show that the scaling behavior of a polymer confined between two liquids does not follow that predicted for polymers adsorbed on solid or soft surfaces such as lipid bilayers. Indeed, our results show that in the diffusive regime the polymer behaves like in bulk solution, following the Zimm model, and with the hydrodynamic interactions dominating its dynamics. Although the presence of the interface does not affect the long-time diffusion properties, it has an influence on the dynamics at short time scale, where for low molecular weight polymers the subdiffusive regime almost disappears. Simulations carried out when the liquid interface is sandwiched between two solid walls show that, when the confinement is a few times larger than the blob size, the Rouse dynamics is recovered.
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Affiliation(s)
- Tseden Taddese
- School
of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - David L. Cheung
- School
of Chemistry, National University of Ireland Galway, Galway, Ireland
| | - Paola Carbone
- School
of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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15
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Sharma GP, Reshetnyak YK, Andreev OA, Karbach M, Müller G. Coil-helix transition of polypeptide at water-lipid interface. JOURNAL OF STATISTICAL MECHANICS (ONLINE) 2015; 2015:P01034. [PMID: 31456824 PMCID: PMC6711616 DOI: 10.1088/1742-5468/2015/01/p01034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present the exact solution of a microscopic statistical mechanical model for the transformation of a long polypeptide between an unstructured coil conformation and an α-helix conformation. The polypeptide is assumed to be adsorbed to the interface between a polar and a non-polar environment such as realized by water and the lipid bilayer of a membrane. The interfacial coil-helix transformation is the first stage in the folding process of helical membrane proteins. Depending on the values of model parameters, the conformation changes as a crossover, a discontinuous transition, or a continuous transition with helicity in the role of order parameter. Our model is constructed as a system of statistically interacting quasiparticles that are activated from the helix pseudo-vacuum. The particles represent links between adjacent residues in coil conformation that form a self-avoiding random walk in two dimensions. Explicit results are presented for helicity, entropy, heat capacity, and the average numbers and sizes of sboth coil and helix segments.
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Affiliation(s)
- Ganga P Sharma
- Department of Physics, University of Rhode Island, Kingston RI 02881, USA
| | - Yana K Reshetnyak
- Department of Physics, University of Rhode Island, Kingston RI 02881, USA
| | - Oleg A Andreev
- Department of Physics, University of Rhode Island, Kingston RI 02881, USA
| | - Michael Karbach
- Fachgruppe Physik, Bergische Universität Wuppertal, D-42097 Wuppertal, Germany
| | - Gerhard Müller
- Department of Physics, University of Rhode Island, Kingston RI 02881, USA
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16
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Komura S, Andelman D. Physical aspects of heterogeneities in multi-component lipid membranes. Adv Colloid Interface Sci 2014; 208:34-46. [PMID: 24439258 DOI: 10.1016/j.cis.2013.12.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 12/07/2013] [Indexed: 01/08/2023]
Abstract
Ever since the raft model for biomembranes has been proposed, the traditional view of biomembranes based on the fluid-mosaic model has been altered. In the raft model, dynamical heterogeneities in multi-component lipid bilayers play an essential role. Focusing on the lateral phase separation of biomembranes and vesicles, we review some of the most relevant research conducted over the last decade. We mainly refer to those experimental works that are based on physical chemistry approach, and to theoretical explanations given in terms of soft matter physics. In the first part, we describe the phase behavior and the conformation of multi-component lipid bilayers. After formulating the hydrodynamics of fluid membranes in the presence of the surrounding solvent, we discuss the domain growth-law and decay rate of concentration fluctuations. Finally, we review several attempts to describe membrane rafts as two-dimensional microemulsion.
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17
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Seki K, Mogre S, Komura S. Diffusion coefficients in leaflets of bilayer membranes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:022713. [PMID: 25353515 DOI: 10.1103/physreve.89.022713] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Indexed: 06/04/2023]
Abstract
We study diffusion coefficients of liquid domains by explicitly taking into account the two-layered structure called leaflets of the bilayer membrane. In general, the velocity fields associated with each leaflet are different and the layers sliding past each other cause frictional coupling. We obtain analytical results of diffusion coefficients for a circular liquid domain in a leaflet, and quantitatively study their dependence on the interleaflet friction. We also show that the diffusion coefficients diverge in the absence of coupling between the bilayer and solvents, even when the interleaflet friction is taken into account. In order to corroborate our theory, the effect of the interleaflet friction on the correlated diffusion is examined.
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Affiliation(s)
- Kazuhiko Seki
- NRI, National Institute of Advanced Industrial Science and Technology (AIST), AIST Central 5, Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan
| | - Saurabh Mogre
- Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400 076, India
| | - Shigeyuki Komura
- Department of Chemistry, Tokyo Metropolitan University, Tokyo 192-0397, Japan
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18
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Meyer H, Semenov AN. Anomalous dynamics in 2D polymer melts. PHYSICAL REVIEW LETTERS 2012; 109:248304. [PMID: 23368397 DOI: 10.1103/physrevlett.109.248304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Indexed: 06/01/2023]
Abstract
The dynamics in polymer monolayers where chains are strongly confined and adopt 2D conformations are drastically different to those in the bulk. It is shown that viscoelastic hydrodynamic interactions play a major role defining the anomalous chain diffusion properties in such systems where chains cannot cross each other. We developed a quantitative analytical theory of polymer subdiffusion in 2D systems revealing a complex behavior controlled by a delicate interplay of inertial, viscoelastic hydrodynamic interactions, finite-box-size and frictional effects. The theory is fully supported by extensive momentum-conserving and Langevin molecular-dynamics simulation data explaining the highly cooperative character of 2D polymer motions.
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Affiliation(s)
- H Meyer
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
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19
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Abstract
We investigate the lateral dynamics in a purely viscous lipid membrane which is supported by a thin polymer sheet (polymer-supported membrane). The generalized frequency-dependent mobility tensor of the polymer-supported membrane is obtained by taking into account the viscoelasticity of the polymer sheet. Due to its viscoelasticity, the cross-correlation functions of two particles embedded in the membrane exhibit an anomalous diffusion. A useful relation for two-point microrheology connecting the cross-correlation function and the modulus of the polymer sheet is provided.
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Affiliation(s)
- Shigeyuki Komura
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397, Japan
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-42-677-2537; Fax: +81-42-677-2525
| | - Sanoop Ramachandran
- Polymer Physics Group, Department of Physics, Free University of Brussels, Campus Plaine, CP 223, Brussels 1050, Belgium; E-Mail:
| | - Kazuhiko Seki
- National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8565, Japan; E-Mail:
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20
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Oppenheimer N, Diamant H. In-plane dynamics of membranes with immobile inclusions. PHYSICAL REVIEW LETTERS 2011; 107:258102. [PMID: 22243117 DOI: 10.1103/physrevlett.107.258102] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Indexed: 05/31/2023]
Abstract
Cell membranes are anchored to the cytoskeleton via immobile inclusions. We investigate the effect of such anchors on the in-plane dynamics of a fluid membrane and mobile inclusions (proteins) embedded in it. The immobile particles lead to a decreased diffusion coefficient of mobile ones and suppress the correlated diffusion of particle pairs. Because of the long-range, quasi-two-dimensional nature of membrane flows, these effects become significant at a low area fraction (below 1%) of immobile inclusions.
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Affiliation(s)
- Naomi Oppenheimer
- Raymond & Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel.
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21
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Seki K, Ramachandran S, Komura S. Diffusion coefficient of an inclusion in a liquid membrane supported by a solvent of arbitrary thickness. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:021905. [PMID: 21929018 DOI: 10.1103/physreve.84.021905] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/12/2011] [Indexed: 05/31/2023]
Abstract
The diffusion coefficient of an inclusion in a liquid membrane is investigated by taking into account the interaction between membranes and bulk solvents of arbitrary thickness. As illustrative examples, the diffusion coefficients of two types of inclusions, a circular domain composed of fluid with the same viscosity as the host membrane and that of a polymer chain embedded in the membrane, are studied. The diffusion coefficients are expressed in terms of the hydrodynamic screening lengths, which vary according to the solvent thickness. When the membrane fluid is dragged by the solvent of finite thickness, via stick boundary conditions, multiple hydrodynamic screening lengths together with the weight factors to the diffusion coefficients are obtained from the characteristic equation. The conditions for which the diffusion coefficients can be approximated by the expression including only a single hydrodynamic screening length are also shown.
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Affiliation(s)
- Kazuhiko Seki
- National Institute of Advanced Industrial Science and Technology AIST Tsukuba Central 5, Higashi 1-1-1, Tsukuba 305-8565, Japan
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