Protein metal complexes as reversible sacrificial bonds in self-healing biopolymers

贝丝是由海洋贻贝分泌的生物聚合纤维，具有自主和内在的自愈行为。由于丝线是基于蛋白质和非细胞的，它们提供了一个吸引人的仿生模型系统，以激发自修复聚合物的发展。先前的研究表明，愈合行为是由可逆的蛋白质-金属交联引起的；然而，交联密度和分布、配体-金属组合的选择或蛋白质亚基的层次组织等因素如何影响自愈行为尚不清楚。我们提出了一个跨学科的研究项目，旨在更好地理解金属-蛋白质复合物作为可逆交联在丝线纤维芯和保护角质层的自愈行为中所起的作用。此外，我们的目标是阐明自我修复行为是如何通过这种交联的高阶组织被修改和增强的。因此，一种比较生物学的方法将使用几个相关物种的线来并行研究愈合行为是如何通过进化来适应和优化不同的身体条件的。通过在分子水平上通过更高层次研究丝线的愈合行为，我们期望提取与材料无关的结构和化学设计原则，以启发自主和内在自愈聚合物的生产。

Byssal threads are biopolymeric fibers secreted by marine mussels that exhibit autonomic and intrinsic self-healing behavior . Because threads are protein-based and acellular, they present an appealing biomimetic model system for inspiring the development of self-healing polymers. Previous studies indicate that healing behavior results from reversible protein-metal cross-links; however, it is still unclear how factors such as cross-link density and distribution, choice of ligand-metal combination, or the hierarchical organization of the protein subunits influence the self-healing behavior. We propose a cross-disciplinary research project directed at better understanding the role metal-protein complexes play as reversible cross-links in the selfhealing behavior of the fibrous core and protective cuticle of byssal threads. Furthermore, we aim to elucidate how self-healing behavior is modified and enhanced through higher order organization of such cross-links. Accordingly, a comparative biological approach using threads from several related species will be undertaken in parallel to examine how healing behavior has been adapted and optimized to different physical conditions by evolution. By investigating the healing behavior of byssal threads at the molecular level up through higher levels of hierarchy, we expect to extract material-independent structural and chemical design principles to inspire the production of autonomic and intrinsic self-healing polymers.