Cation and cardiac glycoside binding sites of the Na,K-ATPase.
From the structural data obtained by systematically altering residues of the Na,K-ATPase, we are beginning to understand portions of how this active cation transporter couples hydrolysis of ATP with the vectorial movement of cations against their ionic gradients. In addition, the inhibitory action of cardiac glycosides and their interaction sites on the protein has focused our attentions on a catalytic core of the protein involving the H5-H6 transmembrane segment. In future investigations, both the ATP and the Na+ sites of the Na,K-ATPase must be uncovered to refine the structural picture of this complex transporter.
Lingrel
J B
JB
Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Ohio 45267-0524, USA. Lingrejb@uc.edu
Argüello
J M
JM
Van Huysse
J
J
Kuntzweiler
T A
TA
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002301:Cardiac Glycosides / Q000378:metabolism*; D002414:Cations, Monovalent / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D007700:Kinetics; D008969:Molecular Sequence Data; D010042:Ouabain / Q000378:metabolism* / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D017433:Protein Structure, Secondary; D012756:Sheep; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000378:metabolism*
D002301:Cardiac Glycosides; D002414:Cations, Monovalent; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium