美国凯斯西储大学医学院药理学系Edward W. Yu研究组取得最新进展。他们提出一种同时解决膜蛋白冷冻电镜（cryo-EM）结构“构建和检索”的方法。相关论文发表在2021年1月6日出版的《自然-方法学》杂志上。

他们开发了一种自下而上的迭代方法，即构建和检索（BaR），该方法可以从多种内膜和外膜蛋白（包括不同大小和尺寸的膜蛋白复合物）中鉴定和确定冷冻电镜结构。异质不纯蛋白质样品。他们还使用BaR方法来阐明大肠杆菌K12粗膜和原始裂解物的结构信息。这些发现表明，有可能在单个异质样品中解决许多相对较小（<100 kDa）和数量较少（<10％）未鉴定的膜蛋白高分辨率结构。重要的是，这些结果突出了cryo-EM在系统结构蛋白质组学中的潜力。

据了解，单粒子cryo-EM已成为结构生物学领域的一项强大技术。然而，无法可靠地生产纯净、均质的膜蛋白样品，阻碍了其结构测定的进展。

附：英文原文

Title: A ‘Build and Retrieve’ methodology to simultaneously solve cryo-EM structures of membrane proteins

Author: Chih-Chia Su, Meinan Lyu, Christopher E. Morgan, Jani Reddy Bolla, Carol V. Robinson, Edward W. Yu

Issue&Volume: 2021-01-06

Abstract: Single-particle cryo-electron microscopy (cryo-EM) has become a powerful technique in the field of structural biology. However, the inability to reliably produce pure, homogeneous membrane protein samples hampers the progress of their structural determination. Here, we develop a bottom-up iterative method, Build and Retrieve (BaR), that enables the identification and determination of cryo-EM structures of a variety of inner and outer membrane proteins, including membrane protein complexes of different sizes and dimensions, from a heterogeneous, impure protein sample. We also use the BaR methodology to elucidate structural information from Escherichia coli K12 crude membrane and raw lysate. The findings demonstrate that it is possible to solve high-resolution structures of a number of relatively small (<100kDa) and less abundant (<10%) unidentified membrane proteins within a single, heterogeneous sample. Importantly, these results highlight the potential of cryo-EM for systems structural proteomics.

DOI: 10.1038/s41592-020-01021-2

Source: https://www.nature.com/articles/s41592-020-01021-2