Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
J Am Chem Soc. 2017 Aug 16;139(32):11106-11116. doi: 10.1021/jacs.7b04986. Epub 2017 Aug 4.
Supramolecular polymerization or assembly of proteins or large macromolecular units by a homogeneous nucleation mechanism can be quite slow and require specific solution conditions. In nature, protein assembly is often regulated by molecules that modulate the electrostatic interactions of the protein subunits for various association strengths. The key to this regulation is the coupling of the assembly process with a reversible or irreversible chemical reaction that occurs within the constituent subunits. However, realizing this complex process by the rational design of synthetic molecules or macromolecules remains a challenge. Herein, we use a synthetic polypeptide-grafted comb macromolecule to demonstrate how the in situ modulation of interactions between the charged macromolecules affects their resulting supramolecular structures. The kinetics of structural formation was studied and can be described by a generalized model of nucleated polymerization containing secondary pathways. Basic thermodynamic analysis indicated the delicate role of the electrostatic interactions between the charged subunits in the reaction-induced assembly process. This approach may be applicable for assembling a variety of ionic soft matters that are amenable to chemical reactions in situ.
蛋白质或大的高分子单元的超分子聚合或组装可以通过均相成核机制进行，其速度通常较慢，并且需要特定的溶液条件。在自然界中，蛋白质的组装通常受到分子的调节，这些分子调节蛋白质亚基的静电相互作用，以产生不同的结合强度。这种调节的关键是将组装过程与在组成亚基内发生的可逆或不可逆化学反应相耦合。然而，通过合理设计合成分子或高分子来实现这一复杂过程仍然是一个挑战。在这里，我们使用一种合成的多肽接枝梳状大分子来证明如何通过原位调节带电大分子之间的相互作用来影响它们的超分子结构。研究了结构形成的动力学，并且可以用包含二级途径的成核聚合的广义模型来描述。基础热力学分析表明，在反应诱导的组装过程中，带电亚基之间的静电相互作用起着微妙的作用。这种方法可能适用于组装各种易于在原位进行化学反应的离子软物质。
