A reconstituted Na+ + K+ pump in liposomes containing purified (Na+ + K+)-ATPase from kidney medulla.
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.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D004285:Dogs; D004789:Enzyme Activation; D007668:Kidney / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D007700:Kinetics; D008081:Liposomes / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D012413:Rubidium / Q000378:metabolism; D012756:Sheep; D012964:Sodium / Q000378:metabolism* / Q000494:pharmacology
D008081:Liposomes; D012964:Sodium; D000251:Adenosine Triphosphatases; D012413:Rubidium; D011188:Potassium