Precise control of the number of conjugated proteins on a nanoparticle surface has long been a highly challenging task. Here, we developed a one-pot, purification-free strategy for valency-controlled conjugation of tandem repeat protein chains on gold nanoparticles. Protein chains were designed to contain multiple, regularly spaced binding modules, which can multivalently interact with coating molecules on nanoparticle surfaces. We discovered that a slow increase of this interaction strength facilitates full participation of repeated binding modules on a protein chain for surface binding (as well as dynamic rearrangement) on a single nanoparticle, which resulted in stable protein chain wrapping around nanoparticles. By varying the protein chain length, a defined number of protein chains were conjugated on gold nanoparticles with difference sizes. Various high-order nanoparticle structures were accurately assembled with these valence-controlled protein–particle conjugates. The present strategy offers a highly dynamic but controlled protein coating approach on solid surfaces of diverse nanostructures. In addition, this work also provides a valuable clue to understand dynamic binding processes of multivalent repeat proteins.

中文翻译：

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通过串联重复蛋白质链的可重新排列的多价相互作用，在纳米粒子上实现价态控制的蛋白质缀合

长期以来，精确控制纳米颗粒表面结合蛋白的数量一直是一项极具挑战性的任务。在这里，我们开发了一种一锅法、免纯化策略，用于在金纳米粒子上进行价态控制的串联重复蛋白链缀合。蛋白质链被设计成包含多个规则间隔的结合模块，这些结合模块可以与纳米粒子表面的涂层分子进行多价相互作用。我们发现，这种相互作用强度的缓慢增加促进了蛋白质链上重复结合模块的充分参与，以在单个纳米粒子上进行表面结合（以及动态重排），从而导致稳定的蛋白质链缠绕在纳米粒子周围。通过改变蛋白质链长度，确定数量的蛋白质链缀合在不同大小的金纳米粒子上。各种高阶纳米粒子结构与这些受价控制的蛋白质-粒子偶联物精确组装。本策略在不同纳米结构的固体表面上提供了一种高度动态但受控的蛋白质涂层方法。此外，这项工作还为理解多价重复蛋白的动态结合过程提供了有价值的线索。