A voltage-activated cation transport pathway associated with the sodium pump.
In proteoliposomes containing reconstituted shark Na,K-ATPase, inside positive potentials open a cation conductance characterized by a voltage-dependence very similar to that found in mammalian erythrocytes. In both proteoliposomes and erythrocytes, the voltage-activated pathway is inhibited by external oligomycin, which traps the Na,K-ATPase in a Na-occluded E1 form. These results indicate that a cation permeable pathway, activated by inside positive potentials, can be ascribed to the Na-K pump--possibly through interaction with its gating mechanism.
Halperin
J A
JA
Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, MA 02115.
Cornelius
F
F
D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007476:Ionophores / Q000494:pharmacology; D007700:Kinetics; D008081:Liposomes; D008564:Membrane Potentials; D009840:Oligomycins / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism; D012754:Sharks; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D014634:Valinomycin / Q000494:pharmacology
D007476:Ionophores; D008081:Liposomes; D009840:Oligomycins; D011510:Proteolipids; C020485:proteoliposomes; D014634:Valinomycin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium