Tyukodi Botond, Mohajerani Farzaneh, Hall Douglas M, Grason Gregory M, Hagan Michael F
Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02454, United States.
Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States.
ACS Nano. 2022 Jun 28;16(6):9077-9085. doi: 10.1021/acsnano.2c00865. Epub 2022 May 31.
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 toward 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.
我们使用计算建模来研究基于粒子的几何受挫组装模型的组装热力学，在该模型中，亚基的局部堆积几何结构与均匀、无应变的大规模组装不相容。该模型考虑离散的三角形亚基，这些亚基驱动组装形成封闭的六边形有序微管，但具有局部有利于负高斯曲率的几何结构。我们使用动态蒙特卡罗模拟和增强采样方法来计算自由能景观以及相应的自组装行为，该行为是控制组装驱动力和受挫程度的实验可及参数的函数。结果确定了发生有限温度自限组装的参数范围，其中平衡组装尺寸分布在明确的有限尺寸附近急剧峰值化。模拟还确定了系统能够摆脱受挫并组装到无限尺寸的两种机制，并确定了抑制无界生长的亚基的粒子尺度特性。
