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Subbotin AV, Semenov AN. The Structure of Polyelectrolyte Complex Coacervates and Multilayers. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02470] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Andrey V. Subbotin
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskii prosp. 29, Moscow 119991, Russia
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii prosp. 31, Moscow 119071, Russia
| | - Alexander N. Semenov
- Institut Charles Sadron, CNRS - UPR 22, Université de Strasbourg, 23 rue du Loess, 67034 Strasbourg Cedex 2, France
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2
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Theoretical Modeling of Chemical Equilibrium in Weak Polyelectrolyte Layers on Curved Nanosystems. Polymers (Basel) 2020; 12:polym12102282. [PMID: 33027995 PMCID: PMC7601300 DOI: 10.3390/polym12102282] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022] Open
Abstract
Surface functionalization with end-tethered weak polyelectrolytes (PE) is a versatile way to modify and control surface properties, given their ability to alter their degree of charge depending on external cues like pH and salt concentration. Weak PEs find usage in a wide range of applications, from colloidal stabilization, lubrication, adhesion, wetting to biomedical applications such as drug delivery and theranostics applications. They are also ubiquitous in many biological systems. Here, we present an overview of some of the main theoretical methods that we consider key in the field of weak PE at interfaces. Several applications involving engineered nanoparticles, synthetic and biological nanopores, as well as biological macromolecules are discussed to illustrate the salient features of systems involving weak PE near an interface or under (nano)confinement. The key feature is that by confining weak PEs near an interface the degree of charge is different from what would be expected in solution. This is the result of the strong coupling between structural organization of weak PE and its chemical state. The responsiveness of engineered and biological nanomaterials comprising weak PE combined with an adequate level of modeling can provide the keys to a rational design of smart nanosystems.
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3
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Caetano DLZ, de Carvalho SJ, Metzler R, Cherstvy AG. Critical adsorption of multiple polyelectrolytes onto a nanosphere: splitting the adsorption-desorption transition boundary. J R Soc Interface 2020; 17:20200199. [PMID: 32574545 PMCID: PMC7328387 DOI: 10.1098/rsif.2020.0199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/03/2020] [Indexed: 01/09/2023] Open
Abstract
Employing extensive Monte Carlo computer simulations, we investigate in detail the properties of multichain adsorption of charged flexible polyelectrolytes (PEs) onto oppositely charged spherical nanoparticles (SNPs). We quantify the conditions of critical adsorption-the phase-separation curve between the adsorbed and desorbed states of the PEs-as a function of the SNP surface-charge density and the concentration of added salt. We study the degree of fluctuations of the PE-SNP electrostatic binding energy, which we use to quantify the emergence of the phase subtransitions, including a series of partially adsorbed PE configurations. We demonstrate how the phase-separation adsorption-desorption boundary shifts and splits into multiple subtransitions at low-salt conditions, thereby generalizing and extending the results for critical adsorption of a single PE onto the SNP. The current findings are relevant for finite concentrations of PEs around the attracting SNP, such as the conditions for PE adsorption onto globular proteins carrying opposite electric charges.
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Affiliation(s)
- Daniel L. Z. Caetano
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, Campus São José do Rio Preto, 15054-000 Brazil
- Institute of Chemistry, State University of Campinas (UNICAMP), 13083-970 Campinas, Brazil
- Center for Computational Engineering and Sciences, State University of Campinas (UNICAMP), 13083-970 Campinas, Brazil
| | - Sidney J. de Carvalho
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, Campus São José do Rio Preto, 15054-000 Brazil
| | - Ralf Metzler
- Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Andrey G. Cherstvy
- Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam-Golm, Germany
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4
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Portnov IV, Potemkin II. Interpolyelectrolyte Complex Dissociation vs Polyelectrolyte Desorption from Oppositely Charged Surface upon Salt Addition. J Phys Chem B 2020; 124:914-920. [PMID: 31935090 DOI: 10.1021/acs.jpcb.9b10678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The structure of complexes formed by oppositely charged polyelectrolytes and adsorbed layers on charged surfaces is sensitive to low-molecular-weight salt. Furthermore, if the concentration exceeds some threshold value, the complexes and adsorbed chains can be "dissolved". This is due to the screening of the electrostatic interactions between charged units. In the current paper, we perform a comparative analysis of "dissolution" (dissociation) of complexes and layers upon addition of salt. For this, the conventional Brownian dynamics of computer simulations is used. We demonstrate that the complex based on linear chains dissociates at lower salt concentration than that required for desorption of equivalent chains from an oppositely charged surface. The physical reason is the difference in the symmetry of the electric field, which binds the chains into the complex (layer). In the salt-free regime, the intensity of the electric field (and attractive force) between two linear chains decays with the distance R between them, like for two spherical objects, ∼R-2, if R is bigger than the characteristic size of the chain. On the contrary, the attractive force of the chain to the infinite surface does not depend on the distance to the surface (the electric field is constant). Therefore, if attractive forces in the condensed states of the two systems are equal, one needs to add more salt to screen the constant force than the decaying one. The computer simulation results on the adsorption of the chains were compared with the experimental data obtained for adsorption of cationic poly(4-vinylpyridine) on the surface of anionic liposomes. Good quantitative agreement was achieved.
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Affiliation(s)
- Ivan V Portnov
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation.,DWI-Leibniz Institute for Interactive Materials , Aachen 52056 , Germany.,A. N. Nesmeyanov Institute of Organoelement Compounds , Russian Academy of Sciences , Moscow 119991 , Russian Federation
| | - Igor I Potemkin
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation.,DWI-Leibniz Institute for Interactive Materials , Aachen 52056 , Germany.,National Research South Ural State University , Chelyabinsk 454080 , Russian Federation
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5
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Sakhawoth Y, Michot L, Levitz P, Rollet AL, Sirieix-Plenet J, Merino DH, Malikova N. Aggregation of Plate-like Colloids Induced by Charged Polymer Chains: Organization at the Nanometer Scale Tuned by Polymer Charge Density. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10937-10946. [PMID: 31318560 DOI: 10.1021/acs.langmuir.9b00939] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We study the aggregation of charged plate-like colloids, Na-montmorillonite clays, in the presence of ionenes, oppositely charged polymer chains. The choice of the charged polymer allows tuning its linear charge density to match/mismatch the average charge separation on the clay surfaces. We assess the nanoscale structure of the aggregates formed by small-angle X-ray and neutron scattering. The nanoscale features of the formed clay aggregates are dominated by the presence of a stacking peak, giving clear evidence for the formation of clay tactoids, that is, a face-to-face aggregation geometry of the clay platelets. The chain charge density of ionenes influences not only the stacking repeat distance within the clay tactoids but also the extent of stacking and abundance of the tactoids. We may distinguish two regimes as a function of clay and ionene polymer charge densities (ρc and ρp, respectively). The first regime applies to ρp > ρc and ρp ≈ ρc, that is, for highly and "matching" charged chains. Under these conditions, the intercalated chains lie in a flat conformation within the tactoids, irrespective of the ionic strength (within the range studied, i.e., up to 0.05 M NaBr). For weakly charged chains, ρp < ρc, undulation of the ionene chains within the tactoid is seen. The degree of undulation increases with ionic strength due to the decreasing persistence length of the ionene chains. The extent of stacking (5-10 platelets per tactoid) is a general feature of all the systems, and its origin remains unknown. The system corresponding to the closest match in charge separations on the clay surface and on the polymer chain (ρp ≈ ρc) features the highest abundance of tactoids. This coincides with the highest macroscopic density as deduced from simple visual inspection of sediment volumes. This leads to the open question regarding the link between the density at the nanoscale and the macroscopic density and sedimentation behavior of the aggregate.
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Affiliation(s)
- Yasine Sakhawoth
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
| | - Laurent Michot
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
| | - Pierre Levitz
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
| | - Anne-Laure Rollet
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
| | - Juliette Sirieix-Plenet
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
| | - Daniel Hermida Merino
- ESRF (The European Synchrotron Radiation Facility) , 71 Avenue des Martyrs , 38000 Grenoble France
| | - Natalie Malikova
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Université, CNRS , 75005 Paris , France
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6
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Shojaei HR, Muthukumar M. Adsorption and encapsulation of flexible polyelectrolytes in charged spherical vesicles. J Chem Phys 2018; 146:244901. [PMID: 28668020 DOI: 10.1063/1.4986961] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a theory of adsorption of flexible polyelectrolytes on the interior and exterior surfaces of a charged vesicle in an electrolyte solution. The criteria for adsorption and the density profiles of the adsorbed polymer chain are derived in terms of various characteristics of the polymer, vesicle, and medium, such as the charge density and length of the polymer, charge density and size of the vesicle, electrolyte concentration and dielectric constant of the medium. For adsorption inside the vesicle, the competition between the loss of conformational entropy and gain in adsorption energy results in two kinds of encapsulated states, depending on the strength of the polymer-vesicle interaction. By considering also the adsorption from outside the vesicle, we derive the entropic and energy contributions to the free energy change to transfer an adsorbed chain in the interior to an adsorbed chain on the exterior. In this paper, we have used the Wentzel-Kramers-Brillouin (WKB) method to solve the equation for the probability distribution function of the chain. The present WKB results are compared with the previous results based on variational methods. The WKB and variational results are in good agreement for both the interior and exterior states of adsorption, except in the zero-salt limit for adsorption in the exterior region. The adsorption criteria and density profiles for both the interior and exterior states are presented in terms of various experimentally controllable variables. Calculation of the dependencies of free energy change to transfer an adsorbed chain from the interior to the exterior surface on salt concentration and vesicle radius shows that the free energy penalty to expel a chain from a vesicle is only of the order of thermal energy.
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Affiliation(s)
- H R Shojaei
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - M Muthukumar
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
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7
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Caetano DLZ, de Carvalho SJ. Conformational properties of block-polyampholytes adsorbed on charged cylindrical surfaces. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2017; 40:33. [PMID: 28337649 DOI: 10.1140/epje/i2017-11525-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/08/2017] [Indexed: 06/06/2023]
Abstract
Polyampholytes are polymers that have positive and negative monomers along their chain. The adsorption of polyampholytes on charged surfaces has been the subject of a large number of theoretical, computational and experimental studies due to its importance in a variety of bio and nanothechnological systems. However, computational studies focusing on interaction between polyampholytes and cylindrical charged surfaces are rather scarce. This study, therefore, aims to investigate the conformational properties of block-polyampholytes in the presence of a negatively charged cylinder by means of Metropolis Monte Carlo simulations. Adopting a simplified model in which the electrolyte solution is treated at the Debye-Hückel level, the effects of the ionic strength, the linear charge density of the cylinder and the block length on monomers distributions have been investigated. It was found that increasing the salt concentration promotes a transition from a conformation characterized by large loops to a necklace-like conformation parallel to the surface. It was also shown that, at low cylinder charge density, the increase in salt concentration and the length of the blocks lead to a change in the orientation of the adsorbed chain.
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Affiliation(s)
- Daniel L Z Caetano
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Rua Cristovão Colombo 2265, Jd. Nazareth, 15054-000, São José do Rio Preto, São Paulo, Brazil
| | - Sidney J de Carvalho
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Rua Cristovão Colombo 2265, Jd. Nazareth, 15054-000, São José do Rio Preto, São Paulo, Brazil.
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8
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Peng B, Muthukumar M. Modeling competitive substitution in a polyelectrolyte complex. J Chem Phys 2016; 143:243133. [PMID: 26723618 DOI: 10.1063/1.4936256] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have simulated the invasion of a polyelectrolyte complex made of a polycation chain and a polyanion chain, by another longer polyanion chain, using the coarse-grained united atom model for the chains and the Langevin dynamics methodology. Our simulations reveal many intricate details of the substitution reaction in terms of conformational changes of the chains and competition between the invading chain and the chain being displaced for the common complementary chain. We show that the invading chain is required to be sufficiently longer than the chain being displaced for effecting the substitution. Yet, having the invading chain to be longer than a certain threshold value does not reduce the substitution time much further. While most of the simulations were carried out in salt-free conditions, we show that presence of salt facilitates the substitution reaction and reduces the substitution time. Analysis of our data shows that the dominant driving force for the substitution process involving polyelectrolytes lies in the release of counterions during the substitution.
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Affiliation(s)
- B Peng
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - M Muthukumar
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
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9
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Li HM, Chen YW, Zhu YJ, Tong CH. Numerical study of the interplay of monomer-surface electrostatic and non-electrostatic interactions in the adsorption of weak polyelectrolytes on oppositely charged surfaces. CHINESE JOURNAL OF POLYMER SCIENCE 2016. [DOI: 10.1007/s10118-016-1780-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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10
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Salt-induced reentrant stability of polyion-decorated particles with tunable surface charge density. Colloids Surf B Biointerfaces 2016; 137:109-20. [DOI: 10.1016/j.colsurfb.2015.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 01/17/2023]
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11
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Wagner J, Erdemci-Tandogan G, Zandi R. Adsorption of annealed branched polymers on curved surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:495101. [PMID: 26574170 DOI: 10.1088/0953-8984/27/49/495101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The behavior of annealed branched polymers near adsorbing surfaces plays a fundamental role in many biological and industrial processes. Most importantly single stranded RNA in solution tends to fold up and self-bind to form a highly branched structure. Using a mean field theory, we both perturbatively and numerically examine the adsorption of branched polymers on surfaces of several different geometries in a good solvent. Independent of the geometry of the wall, we observe that as branching density increases, surface tension decreases. However, we find a coupling between the branching density and curvature in that a further lowering of surface tension occurs when the wall curves towards the polymer, but the amount of lowering of surface tension decreases when the wall curves away from the polymer. We find that for branched polymers confined into spherical cavities, most of branch-points are located in the vicinity of the interior wall and the surface tension is minimized for a critical cavity radius. For branch polymers next to sinusoidal surfaces, we find that branch-points accumulate at the valleys while end-points on the peaks.
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Affiliation(s)
- Jef Wagner
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA
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12
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Budkov YA, Kolesnikov AL, Georgi N, Nogovitsyn EA, Kiselev MG. A new equation of state of a flexible-chain polyelectrolyte solution: Phase equilibria and osmotic pressure in the salt-free case. J Chem Phys 2015; 142:174901. [DOI: 10.1063/1.4919251] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Yu. A. Budkov
- G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo, Russia
- National Research University Higher School of Economics, Department of Applied Mathematics, Moscow, Russia
| | - A. L. Kolesnikov
- Ivanovo State University, Ivanovo, Russia
- Institut für Nichtklassische Chemie e.V., Universitat Leipzig, Leipzig, Germany
| | - N. Georgi
- Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany
| | | | - M. G. Kiselev
- G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo, Russia
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13
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Lee DJO. Collapse and coexistence for a molecular braid with an attractive interaction component subject to mechanical forces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:145101. [PMID: 25788398 DOI: 10.1088/0953-8984/27/14/145101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dual mechanical braiding experiments provide a useful tool with which to investigate the nature of interactions between rod-like molecules, for instance actin and DNA. In conditions close to molecular condensation, one would expect an appearance of a local minimum in the interaction potential between the two molecules. We investigate this situation, introducing an attractive component into the interaction potential, using a model developed for describing such experiments. We consider both attractive interactions that do not depend on molecular structure and those which depend on a DNA-like helix structure. In braiding experiments, an attractive term may lead to certain effects. A local minimum may cause molecules to collapse from a loosely braided configuration into a tight one, occurring at a critical value of the moment applied about the axis of the braid. For a fixed number of braid pitches, this may lead to coexistence between the two braiding states, tight and loose. Coexistence implies certain proportions of the braid are in each state, their relative size depending on the number of braid pitches. This manifests itself as a linear dependence in numerically calculated quantities as functions of the number of braid pitches. Also, in the collapsed state, the braid radius stays roughly constant. Furthermore, if the attractive interaction is helix dependent, the left-right handed braid symmetry is broken. For a DNA like charge distribution, using the Kornyshev-Leikin interaction model, our results suggest that significant braid collapse and coexistence only occurs for left handed braids. Regardless of the interaction model, the study highlights the possible qualitative physics of braid collapse and coexistence; and the role helix specific forces might play, if important. The model could be used to connect other microscopic theories of interaction with braiding experiments.
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Affiliation(s)
- Dominic J O' Lee
- Department of Chemistry, Imperial College London, SW7 2AZ, London, UK
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14
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Cherstvy AG, Petrov EP. Modeling DNA condensation on freestanding cationic lipid membranes. Phys Chem Chem Phys 2014; 16:2020-37. [PMID: 24343177 DOI: 10.1039/c3cp53433b] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Motivated by recent experimental observations of a rapid spontaneous DNA coil-globule transition on freestanding cationic lipid bilayers, we propose simple theoretical models for DNA condensation on cationic lipid membranes. First, for a single DNA rod, we examine the conditions of full wrapping of a cylindrical DNA-like semi-flexible polyelectrolyte by an oppositely charged membrane. Then, for two parallel DNA rods, we self-consistently analyze the shape and the extent of the membrane enveloping them, focusing on membrane elastic deformations and the membrane-DNA embracing angle, which enables us to compute the membrane-mediated DNA-DNA interactions. We examine the effects of the membrane composition and its charge density, which are the experimentally tunable parameters. We show that membrane-driven rod-rod attraction is more pronounced for higher charge densities and for smaller surface tensions of the membrane. Thus, we demonstrate that for a long DNA chain adhered to a cationic lipid membrane, such membrane-induced DNA-DNA attraction can trigger compaction of DNA.
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Affiliation(s)
- Andrey G Cherstvy
- Institute for Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany.
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de Oliveira VM, de Carvalho SJ. Adsorption of pH-responsive polyelectrolyte chains onto spherical macroions. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2014; 37:29. [PMID: 25160485 DOI: 10.1140/epje/i2014-14075-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/22/2014] [Accepted: 08/05/2014] [Indexed: 06/03/2023]
Abstract
The adsorption of pH-responsive polyelectrolyte chains onto oppositely charged spherical macroions is investigated through Metropolis Monte Carlo simulations and the Weighted Histogram Analysis Method. In this case, the polymer charge density is susceptible to the solution conditions, such as salt concentration and pH, as well as the presence of other charged species. Thus, the pH and ionic strength variations leads to abrupt variations of the conformational and electric properties of the chain, as a result of first-order-like transition between the adsorbed and desorbed states. The diagram of states as a function of ionic strenght and p H is provided. Despite the inhomogeneities in the polyelectrolyte charge distribution induced by the macroion presence and its dependence on ionic strength, the scaling relation between the macromolecular charge densities and the critical Debye length is obtained in agreement with experimental investigations.
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Affiliation(s)
- V M de Oliveira
- Instituto de Biociências, Letras e Ciências Exatas, UNESP - Univ Estadual Paulista; Departamento de Física, Rua Cristovão Colombo 2265, Jd. Nazareth, 15054-000, São José do Rio Preto, São Paulo, Brazil
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16
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Luque-Caballero G, Martín-Molina A, Quesada-Pérez M. Polyelectrolyte adsorption onto like-charged surfaces mediated by trivalent counterions: A Monte Carlo simulation study. J Chem Phys 2014; 140:174701. [DOI: 10.1063/1.4872263] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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