| Abstract: | Liposomes containing either purified or microsomal (Na+,K+)-ATPase preparations from lamb kidney medulla catalyzed ATP-dependent transport of Na+ and K+ with a ratio of approximately 3Na+ to 2K+, which was inhibited by ouabain. Similar results were obtained with liposomes containing a partially purified (Na+,K+)-ATPase from cardiac muscle. This contrasts with an earlier report by Goldin and Tong (J. Biol. Chem. 249, 5907-5915, 1974), in which liposomes containing purified dog kidney (Na+,K+)-ATPase did not transport K+ but catalyzed ATP-dependent symport of Na+ and Cl-. When purified by our procedure, dog kidney (Na+,K+)-ATPase showed some ability to transport K+ but the ratio of Na+ : K+ was 5 : 1. |
