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arXiv · 2109.01174

Thermodynamic size control in curvature-frustrated tubules: Self-limitation with open boundaries

Botond Tyukodi·Farzaneh Mohajerani·Douglas M. Hall·Gregory M. Grason·Michael F. Hagan
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Abstract

We use computational modeling to investigate the assembly thermodynamics of a particle-based model for geometrically frustrated assembly, in which the local packing geometry of subunits is incompatible with uniform, strain-free large-scale assembly. The model considers discrete triangular subunits that drive assembly towards a closed, hexagonal-ordered tubule, but have geometries that locally favor negative Gaussian curvature. We use dynamical Monte Carlo simulations and enhanced sampling methods to compute the free energy landscape and corresponding self-assembly behavior as a function of experimentally accessible parameters that control assembly driving forces and the magnitude of frustration. The results determine the parameter range where finite-temperature self-limiting assembly occurs, in which the equilibrium assembly size distribution is sharply peaked around a well-defined finite size. The simulations also identify two mechanisms by which the system can escape frustration and assemble to unlimited size, and determine the particle-scale properties of subunits that suppress unbounded growth.

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Botond Tyukodi, Farzaneh Mohajerani, Douglas M. Hall, Gregory M. Grason, Michael F. Hagan. 2021-09-02. Thermodynamic size control in curvature-frustrated tubules: Self-limitation with open boundaries. https://arxiv.org/abs/2109.01174

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