The beauty, symmetry, and functionality of icosahedral virus capsids has attracted the attention of biologists, physicists, and mathematicians ever since they were first observed. Viruses and protein cages assemble into functional architectures in a range of sizes, shapes, and symmetries. To fulfill their biological roles, these structures must self-assemble, resist stress, and are often dynamic. The increasing use of icosahedral capsids and cages in materials science has driven the need to quantify them in terms of structural properties such as rigidity, stiffness, and viscoelasticity. In this study, we employed Quartz Crystal Microbalance with Dissipation technology (QCM-D) to characterize and compare the mechanical rigidity of different protein cages and viruses. We attempted to unveil the relationships between rigidity, radius, shell thickness, and triangulation number. We show that the rigidity and triangulation numbers are inversely related to each other and the comparison of rigidity and radius also follows the same trend. Our results suggest that subunit orientation, protein–protein interactions, and protein–nucleic acid interactions are important for the resistance to deformation of these complexes, however, the relationships are complex and need to be explored further. The QCM-D based viscoelastic measurements presented here help us elucidate these relationships and show the future prospect of this technique in the field of physical virology and nano-biotechnology.

中文翻译：

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研究二十面体病毒、病毒基纳米材料和蛋白质笼的粘弹性

自从首次观察到二十面体病毒衣壳的美丽、对称性和功能性，就吸引了生物学家、物理学家和数学家的注意。病毒和蛋白质笼组装成各种大小、形状和对称性的功能结构。为了发挥它们的生物学作用，这些结构必须自组装、抵抗压力并且通常是动态的。在材料科学中越来越多地使用二十面体衣壳和笼子，促使需要根据刚度、刚度和粘弹性等结构特性对其进行量化。在这项研究中，我们采用石英晶体微天平和耗散技术 (QCM-D) 来表征和比较不同蛋白质笼和病毒的机械刚度。我们试图揭示刚度、半径、壳厚度之间的关系，和三角测量数。我们表明刚度和三角剖分数呈负相关，并且刚度和半径的比较也遵循相同的趋势。我们的研究结果表明，亚基方向、蛋白质-蛋白质相互作用和蛋白质-核酸相互作用对于这些复合物的变形抵抗很重要，但是，这些关系很复杂，需要进一步探索。这里介绍的基于 QCM-D 的粘弹性测量有助于我们阐明这些关系并展示该技术在物理病毒学和纳米生物技术领域的未来前景。我们的研究结果表明，亚基方向、蛋白质-蛋白质相互作用和蛋白质-核酸相互作用对于这些复合物的变形抵抗很重要，但是，这些关系很复杂，需要进一步探索。这里介绍的基于 QCM-D 的粘弹性测量有助于我们阐明这些关系并展示该技术在物理病毒学和纳米生物技术领域的未来前景。我们的研究结果表明，亚基方向、蛋白质-蛋白质相互作用和蛋白质-核酸相互作用对于这些复合物的变形抗性很重要，然而，这些关系很复杂，需要进一步探索。这里介绍的基于 QCM-D 的粘弹性测量有助于我们阐明这些关系并展示该技术在物理病毒学和纳米生物技术领域的未来前景。