美国加州大学洛杉矶分校Z. Hong Zhou团队开发新型结构蛋白组学分析方法。这一研究成果于2019年11月25日在线发表在国际学术期刊《自然—方法学》上。

研究人员报道了一种自下而上的内源性结构蛋白质组学方法，其中从直接从内源性细胞环境中富集的未鉴定蛋白质复合物从头开始重建近原子分辨率的冷冻电镜（cryoEM）图，然后进行蛋白质的鉴定和原子建模。

使用cryoID（研究人员所开发的程序）识别每个复合物中的蛋白质，可从头开始在cryoEM图中识别蛋白质。作为原理的证明，研究人员将这种方法应用于引起疟疾的恶性疟原虫（一种无法用于常规结构生物学方法的生物），以获得涉及寄生虫红细胞内存活的多种蛋白质复合物的原子模型。

这一方法广泛适用于确定直接从内源性来源富集的未鉴定蛋白质复合物结构。

据悉，X射线晶体学通常需要突变或截短的非天然构建体，并且受到膜蛋白和大型多组分复合物的挑战。

附：英文原文

Title: Bottom-up structural proteomics: cryoEM of protein complexes enriched from the cellular milieu

Author: Chi-Min Ho, Xiaorun Li, Mason Lai, Thomas C. Terwilliger, Josh R. Beck, James Wohlschlegel, Daniel E. Goldberg, Anthony W. P. Fitzpatrick, Z. Hong Zhou

Issue&Volume: 2019-11-25

Abstract: X-ray crystallography often requires non-native constructs involving mutations or truncations, and is challenged by membrane proteins and large multicomponent complexes. We present here a bottom-up endogenous structural proteomics approach whereby near-atomic-resolution cryo electron microscopy (cryoEM) maps are reconstructed ab initio from unidentified protein complexes enriched directly from the endogenous cellular milieu, followed by identification and atomic modeling of the proteins. The proteins in each complex are identified using cryoID, a program we developed to identify proteins in ab initio cryoEM maps. As a proof of principle, we applied this approach to the malaria-causing parasite Plasmodium falciparum, an organism that has resisted conventional structural-biology approaches, to obtain atomic models of multiple protein complexes implicated in intraerythrocytic survival of the parasite. Our approach is broadly applicable for determining structures of undiscovered protein complexes enriched directly from endogenous sources.

DOI: 10.1038/s41592-019-0637-y

Source: https://www.nature.com/articles/s41592-019-0637-y