期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1992
卷号：89
期号：20
页码：9632-9636
DOI：10.1073/pnas.89.20.9632
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The synaptic surface of the acetylcholine receptor in membranes from Torpedo californica electric organ has been imaged by scanning tunneling microscopy. The molecule appears pentameric, with one major and four minor protrusions rising above the surface, and these protrusions encompass a large central cavity. The outer diameter of the molecule is 69 +/- 10 A, while the diameter of the cavity, measured at the widest complete contour line delimiting the opening, is 26 +/- 7 A. The images and dimensions obtained are consistent with the structure determined from hybrid density maps obtained by x-ray diffraction and electron microscopy. Thus, scanning tunneling microscopy can be used to obtain overall dimensions and low-resolution structural features of the surface of a membrane-embedded protein.
