High-resolution single particle electron cryomicroscopy of membrane protein complexes

膜蛋白复合物的高分辨率单颗粒电子冷冻显微镜

• 批准号: 401724-2012
• 负责人: Rubinstein, John
• 金额: $ 3.5万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=529334
• 关键词: resolution; single; particle; electron; cryomicroscopy

BACKGROUND: Cell membranes differentiate a cell from its external environment. Proteins that reside within cell membranes, known as membrane proteins, serve as the gateway to cells. These proteins transport chemicals across membranes and allow cells to communicate with each other and sense their external environment. Understanding how cells carry out these activities requires determining the 3-D structures of membrane proteins. Unfortunately, it is often difficult or impossible to determine the structures of membrane proteins by traditional methods such as X-ray crystallography or nuclear magnetic resonance spectroscopy. Single particle electron cryomicroscopy (cryo-EM) is a method uniquely capable of investigating the structures of large membrane proteins. In cryo-EM, proteins are flash frozen and imaged with an electron microscope. Computational image analysis allows information from many images to be combined into a 3-D map of the protein. We, and one or two other groups, have been able to use single particle cryo-EM to obtain resolutions of ~ 1 nm (one millionth of a millimeter) when studying membrane proteins. At these resolutions, the features that explain how the proteins function start to become visible.

背景：细胞膜将细胞与其外部环境区分开。 驻留在细胞膜内的蛋白质（称为膜蛋白）是通往细胞的门户。 这些蛋白质在跨膜上运输化学物质，使细胞可以相互通信并感知其外部环境。 了解细胞如何进行这些活性需要确定膜蛋白的3-D结构。 不幸的是，通过传统方法（例如X射线晶体学或核磁共振光谱）来确定膜蛋白的结构通常很难或不可能。 单颗粒电子冷冻显微镜（Cryo-EM）是一种能够独特地研究大膜蛋白结构的方法。 在冷冻EM中，蛋白质被闪烁并用电子显微镜成像。 计算图像分析允许将许多图像的信息组合成蛋白质的3-D图。 在研究膜蛋白时，我们和另外一个组已经能够使用单个粒子冷冻EM来获得〜1 nm（一百万毫米的三分之一）的分辨率。 在这些决议中，解释蛋白质功能如何开始可见的功能。