Martin Fisher School of Physics, Brandeis University, Waltham, MA 02454, USA.
Soft Matter. 2018 Jul 18;14(28):5728-5740. doi: 10.1039/c8sm00129d.
The precise control of assembly and packing of proteins and colloids on curved surfaces has fundamental implications in nanotechnology. In this paper, we describe dynamical simulations of the self-assembly of conical subunits around a spherocylindrical template, and a continuum theory for the bending energy of a triangular lattice with spontaneous curvature on a surface with arbitrary curvature. We find that assembly depends sensitively on mismatches between subunit spontaneous curvature and the mean curvature of the template, as well as anisotropic curvature of the template (mismatch between the two principal curvatures). Our simulations predict assembly morphologies that closely resemble those observed in experiments in which virus capsid proteins self-assemble around metal nanorods. Below a threshold curvature mismatch, our simulations identify a regime of optimal assembly leading to complete, symmetrical particles. Outside of this regime we observe defective particles, whose morphologies depend on the degree of curvature mismatch. To learn how assembly is affected by the nonuniform curvature of a spherocylinder, we also study the simpler cases of assembly around spherical and cylindrical cores. Our results show that both the intrinsic (Gaussian) and extrinsic (mean) curvatures of a template play significant roles in guiding the assembly of anisotropic subunits, providing a rich design space for the formation of nanoscale materials.
蛋白质和胶体在曲面上的组装和堆积的精确控制在纳米技术中有重要的意义。在本文中，我们描述了圆锥亚基围绕球柱模板自组装的动力学模拟，以及在具有任意曲率的表面上具有自发曲率的三角形晶格弯曲能的连续体理论。我们发现，组装的结果对亚基自发曲率和模板平均曲率之间的不匹配，以及模板的各向异性曲率（两个主曲率之间的不匹配）非常敏感。我们的模拟预测了与实验中观察到的病毒衣壳蛋白在金属纳米棒周围自组装非常相似的组装形态。在曲率不匹配的阈值以下，我们的模拟确定了一个导致完整、对称粒子的最佳组装区域。在这个区域之外，我们观察到有缺陷的粒子，其形态取决于曲率不匹配的程度。为了了解组装是如何受到球柱的非均匀曲率的影响，我们还研究了围绕球形和圆柱形核心组装的更简单情况。我们的结果表明，模板的固有（高斯）和外在（平均）曲率都在指导各向异性亚基的组装方面发挥了重要作用，为纳米级材料的形成提供了丰富的设计空间。
