标题： 通过冷冻电镜多体精修测量几何编程胶体组装体的多亚基力学 显示英文标题

标题： Measuring multisubunit mechanics of geometrically-programmed colloidal assemblies via cryo-EM multi-body refinement

摘要： 可编程自组装最近通过精确控制粒子间相互作用和粒子几何形状，实现了复杂结构的创建。 为了实现更加结构复杂、动态和功能化的组装体，需要超越对结构本身的设计，转向对亚单元连接局部柔性的测量和控制，以及其对整个组装体集体力学的影响。 在本研究中，我们展示了一种利用冷冻电子显微镜（cryo-EM）和RELION的多体精修方法来推断多亚单元组装体机械特性的方法。 具体而言，我们分析了自组装成管状结构的DNA折纸亚单元对的波动。 通过使用冷冻电镜测量二聚体的波动，我们提取了诸如弯曲模量和粒子间弹簧常数等机械特性。 这些特性随后被应用于弹性模型以预测组装结果，与实验观察结果一致。 这种方法不仅提供了对纳米粒子力学更深入的理解，还为优化亚单元设计以实现精确组装行为开辟了新途径。 该方法可能在纳米材料的研究中具有更广泛的应用，包括蛋白质组装体，其中理解机械特性与亚单元几何形状之间的相互作用对于控制复杂的自组装结构至关重要。 显示英文摘要

摘要： Programmable self-assembly has recently enabled the creation of complex structures through precise control of the interparticle interactions and the particle geometries. Targeting ever more structurally complex, dynamic, and functional assemblies necessitates going beyond the design of the structure itself, to the measurement and control of the local flexibility of the inter-subunit connections and its impact on the collective mechanics of the entire assembly. In this study, we demonstrate a method to infer the mechanical properties of multisubunit assemblies using cryogenic electron microscopy (cryo-EM) and RELION's multi-body refinement. Specifically, we analyze the fluctuations of pairs of DNA-origami subunits that self-assemble into tubules. By measuring the fluctuations of dimers using cryo-EM, we extract mechanical properties such as the bending modulus and interparticle spring constant. These properties are then applied to elastic models to predict assembly outcomes, which align well with experimental observations. This approach not only provides a deeper understanding of nanoparticle mechanics, but also opens new pathways to refining subunit designs to achieve precise assembly behavior. This methodology could have broader applications in the study of nanomaterials, including protein assemblies, where understanding the interplay of mechanical properties and subunit geometry is essential for controlling complex self-assembled structures.