通过二维晶体的电子显微镜观察揭示的（钠 + 钾）-ATP 酶的三维结构。

Three-dimensional structure of (Na+ + K+)-ATPase revealed by electron microscopy of two-dimensional crystals.

作者信息

Demin V V, Barnakov A N, Kuzin A P, Lunev A V, Modyanov N N, Dzhandzhugazyan K N

出版信息

FEBS Lett. 1985 Oct 7;190(1):73-6. doi: 10.1016/0014-5793(85)80430-0.

Abstract

Prolonged incubation of membrane fragments containing homogeneous (Na+ + K+)-ATPase with Mg2+, K+ and VO-3 at 4 degrees C resulted in formation of two-dimensional crystals of this enzyme with unit cell parameters: a = 66 A, b = 118 A, gamma = 108 degrees. The crystals correspond to the two-sided plane group p21. By combining tilted electron microscopic views of the crystals, a three-dimensional structure of (Na+ + K+)- ATPase was calculated at approximately 20 A resolution. The unit cell is formed by two (alpha beta)-promoters which are in contact in their central parts. The structure was compared with chemical modification and immunochemical data; the arrangement of intra- and extramembrane domains was proposed.

摘要

在4℃下，将含有均一的（Na⁺ + K⁺）-ATP酶的膜片段与Mg²⁺、K⁺和VO₃长时间温育，导致该酶形成二维晶体，其晶胞参数为：a = 66埃，b = 118埃，γ = 108°。这些晶体对应于双面平面群p21。通过组合晶体的倾斜电子显微镜视图，以约20埃的分辨率计算出了（Na⁺ + K⁺）-ATP酶的三维结构。晶胞由两个在中心部分相互接触的（αβ）原聚体形成。将该结构与化学修饰和免疫化学数据进行了比较；提出了膜内和膜外结构域的排列方式。