科學家合成具有生物活性的二元蛋白質
作者：
小柯機器人發布時間：2021/1/7 14:32:56
美國華盛頓大學David Baker和英國劍橋大學MRC分子生物學實驗室Emmanuel Derivery團隊合作研發出具有生物活性的二元蛋白質二級結構。相關論文於2021年1月6日在線發表於《自然》雜誌。
研究人員設計了一種計算方法，該方法通過設計成對二面體蛋白質構造塊之間的剛性界面來共裝配成二元層，並用它設計了p6m晶格。該方法生成的結構可在毫摩爾濃度下溶解，但當以納摩爾濃度組合時，它們則快速組裝成幾乎與體外和細胞內計算設計模型相同的微米級結晶結構，而無需二級結構。由於該結構是從頭設計的，因此可以輕鬆地對組件進行功能化，並重新配置它們的對稱性，從而能夠形成具有表面可區分的配體結構，研究證明了它們可以誘導廣泛的受體簇、下遊蛋白招募和信號傳導。
使用原子力顯微鏡觀察支持層和定量顯微鏡檢測活細胞，研究人員發現在膜上組裝的蛋白具有與體外形成陣列相似的化學計量和結構組成，因此該結構可以對基本無序的底物（例如細胞膜）施加順序。先前報導的細胞表面受體結合組件（例如抗體和納米籠）會被細胞迅速內吞，研究人員發現在細胞表面組裝的大複合物其通過可調的方式抑制內吞作用，從而具有擴大受體參與和逃避免疫的潛在治療意義。
該工作為合成細胞生物學奠定了基礎，其中多蛋白質宏觀結構被設計用於調節細胞反應並重塑合成和生命系統。
據介紹，合成有序的二級結構（例如S層和其類似物）吸引著合成生物學家的注意，但是除了由柔性接頭形成的單個晶格之外，它們僅由一種蛋白質構成。由兩個組件組成的結構具有潛在的優勢，可以調節裝配動力學並具有更複雜的功能。
附：英文原文
Title: Design of biologically active binary protein 2D materials
Author: Ariel J. Ben-Sasson, Joseph L. Watson, William Sheffler, Matthew Camp Johnson, Alice Bittleston, Logeshwaran Somasundaram, Justin Decarreau, Fang Jiao, Jiajun Chen, Ioanna Mela, Andrew A. Drabek, Sanchez M. Jarrett, Stephen C. Blacklow, Clemens F. Kaminski, Greg L. Hura, James J. De Yoreo, Justin M. Kollman, Hannele Ruohola-Baker, Emmanuel Derivery, David Baker
Issue&Volume: 2021-01-06
Abstract: Ordered two-dimensional arrays such as S-layers1,2 and designed analogues3,4,5 have intrigued bioengineers6,7, but with the exception of a single lattice formed with flexible linkers8, they are constituted from just one protein component. Materials composed of two components have considerable potential advantages for modulating assembly dynamics and incorporating more complex functionality9,10,11,12. Here we describe a computational method to generate co-assembling binary layers by designing rigid interfaces between pairs of dihedral protein building blocks, and use it to design a p6m lattice. The designed array components are soluble at millimolar concentrations, but when combined at nanomolar concentrations, they rapidly assemble into nearly crystalline micrometre-scale arrays nearly identical to the computational design model in vitro and in cells without the need for a two-dimensional support. Because the material is designed from the ground up, the components can be readily functionalized and their symmetry reconfigured, enabling formation of ligand arrays with distinguishable surfaces, which we demonstrate can drive extensive receptor clustering, downstream protein recruitment and signalling. Using atomic force microscopy on supported bilayers and quantitative microscopy on living cells, we show that arrays assembled on membranes have component stoichiometry and structure similar to arrays formed in vitro, and that our material can therefore impose order onto fundamentally disordered substrates such as cell membranes. In contrast to previously characterized cell surface receptor binding assemblies such as antibodies and nanocages, which are rapidly endocytosed, we find that large arrays assembled at the cell surface suppress endocytosis in a tunable manner, with potential therapeutic relevance for extending receptor engagement and immune evasion. Our work provides a foundation for a synthetic cell biology in which multi-protein macroscale materials are designed to modulate cell responses and reshape synthetic and living systems.
DOI: 10.1038/s41586-020-03120-8
Source: https://www.nature.com/articles/s41586-020-03120-8