美国华盛顿大学David Baker、William A. Catterall以及Peilong Lu研究组合作取得一项新突破，他们进行了跨膜蛋白孔的计算设计。这一研究成果于2020年8月26日发表在《自然》上。
他们报告了由两个α螺旋同心环形成的蛋白质孔的计算设计，这些同心环在其水溶性和跨膜形式上均稳定且单分散。12螺旋孔和16螺旋孔的水溶性形式的晶体结构与计算设计模型紧密匹配。膜片钳电生理实验表明，当在昆虫细胞中表达时，12螺旋孔的跨膜形式使离子能够以较高的钾离子选择性穿过膜。
离子通道被孔入口处的特定化学修饰所阻塞。当使用体外蛋白质合成方法将其掺入脂质体中时，16螺旋孔的跨膜形式（而不是12螺旋孔）使生物素化的Alexa Fluor 488通过。16螺旋跨膜孔的冷冻电镜结构与设计模型紧密匹配。产生结构上和功能上明确的跨膜孔的能力，为各种应用创建设计通道和孔打开了大门。
研究人员表示，跨膜通道和孔在基本生物学过程和生物技术应用（例如DNA纳米孔测序）中具有关键作用，因此引起了对含孔蛋白设计的极大兴趣。已发现合成的两亲性肽可形成离子通道，并且从头膜蛋白设计和重新设计天然存在的含通道蛋白方面已有新进展。然而，从头开始设计稳定、轮廓分明的跨膜蛋白孔，这些孔能够选择性地传导离子或足够大，以使小分子荧光团能够通过。
附：英文原文
Title: Computational design of transmembrane pores
Author: Chunfu Xu, Peilong Lu, Tamer M. Gamal El-Din, Xue Y. Pei, Matthew C. Johnson, Atsuko Uyeda, Matthew J. Bick, Qi Xu, Daohua Jiang, Hua Bai, Gabriella Reggiano, Yang Hsia, T J Brunette, Jiayi Dou, Dan Ma, Eric M. Lynch, Scott E. Boyken, Po-Ssu Huang, Lance Stewart, Frank DiMaio, Justin M. Kollman, Ben F. Luisi, Tomoaki Matsuura, William A. Catterall, David Baker
Issue&Volume: 2020-08-26
Abstract: Transmembrane channels and pores have key roles in fundamental biological processes1 and in biotechnological applications such as DNA nanopore sequencing2,3,4, resulting in considerable interest in the design of pore-containing proteins. Synthetic amphiphilic peptides have been found to form ion channels5,6, and there have been recent advances in de novo membrane protein design7,8 and in redesigning naturally occurring channel-containing proteins9,10. However, the de novo design of stable, well-defined transmembrane protein pores that are capable of conducting ions selectively or are large enough to enable the passage of small-molecule fluorophores remains an outstanding challenge11,12. Here we report the computational design of protein pores formed by two concentric rings of α-helices that are stable and monodisperse in both their water-soluble and their transmembrane forms. Crystal structures of the water-soluble forms of a 12-helical pore and a 16-helical pore closely match the computational design models. Patch-clamp electrophysiology experiments show that, when expressed in insect cells, the transmembrane form of the 12-helix pore enables the passage of ions across the membrane with high selectivity for potassium over sodium; ion passage is blocked by specific chemical modification at the pore entrance. When incorporated into liposomes using in vitro protein synthesis, the transmembrane form of the 16-helix pore—but not the 12-helix pore—enables the passage of biotinylated Alexa Fluor 488. A cryo-electron microscopy structure of the 16-helix transmembrane pore closely matches the design model. The ability to produce structurally and functionally well-defined transmembrane pores opens the door to the creation of designer channels and pores for a wide variety of applications.
DOI: 10.1038/s41586-020-2646-5
Source: https://www.nature.com/articles/s41586-020-2646-5
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
