Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Nat Commun. 2021 Jan 4;12(1):85. doi: 10.1038/s41467-020-20344-4.
Protein-ligand complexes with catch bonds exhibit prolonged lifetimes when subject to tensile force, which is a desirable yet elusive attribute for man-made nanoparticle interfaces and assemblies. Most designs proposed so far rely on macromolecular linkers with complicated folds rather than particles exhibiting simple dynamic shapes. Here, we establish a scissor-type X-shaped particle design for achieving intrinsic catch bonding ability with tunable force-enhanced lifetimes under thermal excitations. Molecular dynamics simulations are carried out to illustrate equilibrium self-assembly and force-enhanced bond lifetime of dimers and fibers facilitated by secondary interactions that form under tensile force. The non-monotonic force dependence of the fiber breaking kinetics is well-estimated by an analytical model. Our design concepts for shape-changing particles illuminates a path towards novel nanoparticle or colloidal assemblies that have the passive ability to tune the strength of their interfaces with applied force, setting the stage for self-assembling materials with novel mechanical functions and rheological properties.
具有捕获键的蛋白-配体复合物在受到张力时表现出延长的寿命，这是人造纳米粒子界面和组装体所期望但难以实现的属性。迄今为止，大多数设计都依赖于具有复杂折叠的大分子接头，而不是具有简单动态形状的粒子。在这里，我们建立了一种剪刀式 X 形粒子设计，用于在热激发下实现具有可调力增强寿命的固有捕获键合能力。分子动力学模拟用于说明在拉伸力下形成的二级相互作用促进的二聚体和纤维的平衡自组装和力增强键寿命。纤维断裂动力学的非单调力依赖性通过分析模型得到了很好的估计。我们用于变形粒子的设计概念为具有被动能力的新型纳米粒子或胶体组装体指明了一条道路，这些组装体可以通过施加的力来调节其界面的强度，为具有新型机械功能和流变性能的自组装材料奠定了基础。
