Communication: Free energy of ligand-receptor systems forming multimeric complexes

At the heart of the structured architecture and complex dynamics of biological systems are specific and timely interactions operated by biomolecules. In many instances, biomolecular agents are spatially confined to flexible lipid membranes where, among other functions, they control cell adhesion, motility and tissue formation. Besides being central to several biological processes, multivalent interactions mediated by reactive linkers confined to deformable substrates underpin the design of syntheticbiological platforms and advanced biomimetic materials. Here we review recent advances on the experimental study and theoretical modelling of a heterogeneous class of biomimetic systems in which synthetic linkers mediate multivalent interactions between fluid and deformable colloidal units, including lipid vesicles and emulsion droplets. Linkers are often prepared from synthetic DNA nanostructures, enabling full programmability of the thermodynamic and kinetic properties of their mutual interactions. The coupling of the statistical effects of multivalent interactions with substrate fluidity and deformability gives rise to a rich emerging phenomenology that, in the context of self-assembled soft materials, has been shown to produce exotic phase behaviour, stimuli-responsiveness, and kinetic programmability of the self-assembly process. Applications to (synthetic) biology will also be reviewed.

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“…Employing the notation of Ref. [170], we consider c families of linkers tethered to the CR between two interfaces (see Fig. 9b).…”

Section: Multimeric Bondsmentioning

confidence: 99%

“…19 [157] or, in the presence of multimeric bonds, Eq. 40 [170]. For infinite interfaces, F conf follows from Eq.…”

Section: Programming Self-assembly and Collective Behaviourmentioning

confidence: 99%

Programmable interactions with biomimetic DNA linkers at fluid membranes and interfaces

2019

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“…[23], which models interactions between colloidal particles that result from multimeric ligand-receptor complexes to calculate the free energy per particle in the fluid and solid phases. Briefly, this involves computing the equilibrium densities of the different molecular species-bridges, half-bridges (AL or BL), and unbound strands-and relating those densities to the free energy of multivalent binding between two particles [23]. In our specific case, we compute the surface densities of half bridges ρ 1 and full bridges ρ b from equations of local chemical equilibrium [14,24], starting from the densities of unhybridized strands A and B (ρ A and ρ B ), and the concentration of free linkers (C l ):…”

Section: Mean-field Theorymentioning

confidence: 99%

Linker-Mediated Phase Behavior of DNA-Coated Colloids

et al. 2019

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The possibility of prescribing local interactions between nano-and microscopic components that direct them to assemble in a predictable fashion is a central goal of nanotechnology research. In this article we advance a new paradigm in which self-assembly of DNA-functionalized colloidal particles is programmed using linker oligonucleotides dispersed in solution. We find a phase diagram that is surprisingly rich compared to phase diagrams typical of other DNA-functionalized colloidal particles that interact by direct hybridization, including a re-entrant melting transition upon increasing linker concentration, and show that multiple linker species can be combined together to prescribe many interactions simultaneously. A new theory predicts the observed phase behavior quantitatively without any fitting parameters. Taken together, these experiments and model lay the groundwork for future research in programmable self-assembly, enabling the possibility of programming the hundreds of specific interactions needed to assemble fully-addressable, mesoscopic structures, while also expanding our fundamental understanding of the unique phase behavior possible in colloidal suspensions.arXiv:1902.08883v2 [cond-mat.soft]

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“…We propose a new "hybrid" framework to calculate the free energy of the interactions between such vesicles, that combines state-of-art analytical theories developed for solid particles [29][30][31][35][36][37][38][39] with Monte Carlo simulations that account for configurational costs related to membrane deformability.…”

Section: Introductionmentioning

confidence: 99%

Melting transition in lipid vesicles functionalised by mobile DNA linkers

et al. 2016

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We study phase behaviour of lipid-bilayer vesicles functionalised by ligand-receptor complexes made of synthetic DNA by introducing a modelling framework and a dedicated experimental platform. In particular, we perform Monte Carlo simulations that combine a coarse grained description of the lipid bilayer with state of art analytical models for multivalent ligand-receptor interactions. Using density of state calculations, we derive the partition function in pairs of vesicles and compute the number of ligand-receptor bonds as a function of temperature. Numerical results are compared to microscopy and fluorimetry experiments on large unilamellar vesicles decorated by DNA linkers carrying complementary overhangs. We find that vesicle aggregation is suppressed when the total number of linkers falls below a threshold value. Within the model proposed here, this is due to the higher configurational costs required to form inter-vesicle bridges as compared to intra-vesicle loops, which are in turn related to membrane deformability. Our findings and our numerical/experimental methodologies are applicable to the rational design of liposomes used as functional materials and drug delivery applications, as well as to study inter-membrane interactions in living systems, such as cell adhesion.

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Communication: Free energy of ligand-receptor systems forming multimeric complexes

Cited by 21 publications

References 27 publications

Programmable interactions with biomimetic DNA linkers at fluid membranes and interfaces

Programmable interactions with biomimetic DNA linkers at fluid membranes and interfaces

Linker-Mediated Phase Behavior of DNA-Coated Colloids

Melting transition in lipid vesicles functionalised by mobile DNA linkers

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