Werten P J L, Rémigy H W, de Groot B L, Fotiadis D, Philippsen A, Stahlberg H, Grubmüller H, Engel A
M.E. Müller Institute for Microscopy, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland.
FEBS Lett. 2002 Oct 2;529(1):65-72. doi: 10.1016/s0014-5793(02)03290-8.
Structural information on membrane proteins is sparse, yet they represent an important class of proteins that is encoded by about 30% of all genes. Progress has primarily been achieved with bacterial proteins, but efforts to solve the structure of eukaryotic membrane proteins are also increasing. Most of the structures currently available have been obtained by exploiting the power of X-ray crystallography. Recent results, however, have demonstrated the accuracy of electron crystallography and the imaging power of the atomic force microscope. These instruments allow membrane proteins to be studied while embedded in the bi-layer, and thus in a functional state. The low signal-to-noise ratio of cryo-electron microscopy is overcome by crystallizing membrane proteins in a two-dimensional protein-lipid membrane, allowing its atomic structure to be determined. In contrast, the high signal-to-noise ratio of atomic force microscopy allows individual protein surfaces to be imaged at sub-nanometer resolution, and their conformational states to be sampled. This review summarizes the steps in membrane protein structure determination and illuminates recent progress.
关于膜蛋白的结构信息稀少，然而它们却是一类重要的蛋白质，约占所有基因的30%。目前主要在细菌蛋白方面取得了进展，但解析真核膜蛋白结构的努力也在增加。目前可用的大多数结构是通过利用X射线晶体学的力量获得的。然而，最近的结果证明了电子晶体学的准确性以及原子力显微镜的成像能力。这些仪器能够在膜蛋白嵌入双层膜时，即在其功能状态下对其进行研究。通过在二维蛋白质-脂质膜中使膜蛋白结晶，克服了冷冻电子显微镜低信噪比的问题，从而能够确定其原子结构。相比之下，原子力显微镜的高信噪比使得能够以亚纳米分辨率对单个蛋白质表面进行成像，并对其构象状态进行采样。本综述总结了膜蛋白结构解析的步骤，并阐明了最近的进展。
