Abstract：
Metal-coordination bonds, a highly tunable class of dynamic noncovalent interactions, are pivotal to the function of a variety of protein-based natural materials and have emerged as binding motifs to produce strong, tough, and self-healing bioinspired materials. While natural proteins use clusters of metal-coordination bonds, synthetic materials frequently employ individual bonds, resulting in mechanically weak materials. To overcome this current limitation, we rationally designed a series of elastin-like polypeptide templates with the capability of forming an increasing number of intermolecular histidine-Ni2+ metal-coordination bonds. Using single-molecule force spectroscopy and steered molecular dynamics simulations, we show that templates with three histidine residues exhibit heterogeneous rupture pathways, including the simultaneous rupture of at least two bonds with more-than-additive rupture forces. The methodology and insights developed improve our understanding of the molecular interactions that stabilize metal-coordinated proteins and provide a general route for the design of new strong, metal-coordinated materials with a broad spectrum of dissipative time scales.
摘要：
金属配位键，一类高度可调的动态非共价相互作用，是各种基于蛋白质的天然材料的功能的关键，并已成为产生强大的结合基序，艰难，和自我修复的生物材料。虽然天然蛋白质使用金属配位键簇，合成材料经常使用单独的键，导致机械强度较弱的材料。为了克服这种电流限制，我们合理地设计了一系列弹性蛋白样多肽模板，这些模板具有形成越来越多的分子间组氨酸-Ni2金属配位键的能力。使用单分子力谱和转向分子动力学模拟，我们表明，具有三个组氨酸残基的模板表现出异质破裂途径，包括至少两个键的同时断裂，其断裂力大于添加剂。开发的方法和见解提高了我们对稳定金属配位蛋白质的分子相互作用的理解，并为设计新的强者，具有广泛耗散时间尺度的金属配位材料。
