Uncoupled Na+-efflux on reconstituted shark Na,K-ATPase is electrogenic.
In liposomes with reconstituted shark Na,K-ATPase produced to contain sucrose addition of external Na+ and ATP induce an uncoupled Na+-efflux on inside-out oriented pumps which can be inhibited by digitoxigenin. This flux mode is found to be electrogenic and accompanied by hydrolysis of ATP. The coupling ratio of Nacyt transported per ATP split is 3:1 measured as the initial rate of rise in transmembrane potential and initial rate of liberated Pi.
Cornelius
F
F
Institute of Biophysics, University of Aarhus, Denmark.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004284:Dogfish; D004563:Electrochemistry; D005456:Fluorescent Dyes; D006868:Hydrolysis; D007555:Isoxazoles; D007700:Kinetics; D008081:Liposomes; D008564:Membrane Potentials / Q000187:drug effects; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism* / Q000502:physiology; D014475:Uncoupling Agents
D005456:Fluorescent Dyes; D007555:Isoxazoles; D008081:Liposomes; D015222:Sodium Channels; D014475:Uncoupling Agents; C031184:oxonol VI; D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase