Functional and structural analysis of acetylcholine receptor‐rich membranes after negative staining

FEBS Letters

Hucho, Ferdinand²  Tesche, Bernd¹  Schmiady, Hardi¹  Reinhardt, Sigrid² 

[1] Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Elektronenmikroskopie, Faradayweg 4/6, 1000 Berlin 33, Germany;Institut für Biochemie, Freie Universität Berlin, Fabeckstr. 34/36, 1000 Berlin 33 Germany

关键词: Acetylcholine receptor;    Electron microscopy;    Negative staining;    Image averaging;   

DOI  :  10.1016/0014-5793(84)81050-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Phosphotungstate (pH 7.4) used for negative staining of membranes from Torpedo electric tissue rich in acetylcholine receptor does not affect binding properties and cation permeability of the receptor and its ion channel. Uranyl salts, frequently used for negative staining, precipitate the receptor-rich membranes making measurements of ligand binding and ion-permeability regulation impossible. The gross ultrastructure in the two stains is not significantly different, but for future high-resolution electron microscopy aiming at visualizing structural details of functional receptor molecules it is necessary to resort to a stain preserving native and active receptor. Uranyl salts are not applicable for this purpose. The electron micrographs obtained with phosphotungstate reveal two distinct structures in the receptor-rich membrane: a closed ring (‘doughnut’) and an open ring (‘horseshoe’), with a ratio of abundance of about 3:2.

【 授权许可】

Unknown