A pH induced two-dimensional crystal of membrane-bound Na+,K(+)-ATPase of dog kidney.
Two-dimensional crystals of membrane-bound Na+,K(+)-ATPase were formed in acidic media and their qualities were investigated by electron cryo-microscopy as well as by conventional electron microscopy. At pH 4.8 in sodium citrate buffer, the best crystallization condition, more than 80% of membranes formed crystals. The high ratio allowed high-resolution images to be taken by electron cryo-microscopy. Image processing revealed that they had unique lattice constants (a = 108.7 A, b = 66.2 A, gamma = 104.2 degrees) and had few defects in the crystalline arrays. The reconstituted Fourier map of the ice-embedded crystal showed that there are two high contrast parts in one unit cell.
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
Y
Y
Tahara
S
S
Ohnishi
Y
Y
Fujiyoshi
Y
Y
Kimura
Y
Y
Hayashi
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D003460:Crystallization; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000201:enzymology*; D008854:Microscopy, Electron; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure
D000254:Sodium-Potassium-Exchanging ATPase