Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Department of Mathematics, Saitama University, 255 Shimo-Okubo, Sakuraku, Saitama, 338-8570, Japan.
Nat Commun. 2019 Dec 12;10(1):5687. doi: 10.1038/s41467-019-13594-4.
Cavity creation is a key to the origin of biological functions. Small cavities such as enzyme pockets are created simply through liner peptide folding. Nature can create much larger cavities by threading and entangling large peptide rings, as learned from gigantic virus capsids, where not only chemical structures but the topology of threaded rings must be controlled. Although interlocked molecules are a topic of current interest, they have for decades been explored merely as elements of molecular machines, or as a synthetic challenge. No research has specifically targeted them for, and succesfully achieved, cavity creation. Here we report the emergence of a huge capsular framework via multiple threading of metal-peptide rings. Six equivalent C-propeller-shaped rings, each consisting of four oligopeptides and Ag, are threaded by each other a total of twelve times (crossing number: 24) to assemble into a well-defined 4 nm-sized sphere, which acts as a huge molecular capsule.
腔体的形成是生物功能起源的关键。通过线性肽折叠可以简单地形成小腔体，如酶口袋。大自然可以通过穿线和缠绕大环肽来创造更大的腔体，这一点可以从巨大的病毒衣壳中得到启示，因为在病毒衣壳中，不仅化学结构，而且穿线环的拓扑结构都必须得到控制。尽管互锁分子是当前研究的热点，但几十年来，它们仅被探索作为分子机器的组成部分，或作为合成挑战。没有研究专门针对它们来成功实现腔体的形成。在这里，我们报告了通过金属-肽环的多次穿线形成一个巨大的胶囊状框架。六个等效的 C 型桨状环，每个环由四个寡肽和 Ag 组成，总共相互穿线 12 次（交叉数：24），组装成一个尺寸为 4nm 的规则球体，该球体充当一个巨大的分子胶囊。
