Residues of the Fourth Transmembrane Segments of the Na,K-ATPase and the Gastric H,K-ATPase Contribute to Cation Selectivity*
Mense M, Dunbar L, Blostein R, Caplan M. Residues of the Fourth Transmembrane Segments of the Na,K-ATPase and the Gastric H,K-ATPase Contribute to Cation Selectivity*. Journal Of Biological Chemistry 2000, 275: 1749-1756. PMID: 10636871, DOI: 10.1074/jbc.275.3.1749.Peer-Reviewed Original ResearchMeSH KeywordsAdenosine TriphosphatasesAmino Acid SequenceAnimalsCationsElectrophysiologyH(+)-K(+)-Exchanging ATPaseHydrogen-Ion ConcentrationInhibitory Concentration 50KineticsMolecular Sequence DataMutationOuabainPotassiumRecombinant Fusion ProteinsSequence Homology, Amino AcidSodiumSodium-Potassium-Exchanging ATPaseStomachVanadatesXenopus laevisConceptsFourth transmembrane segmentTransmembrane segmentsATPase assaysK-ATPaseHelical wheel analysisTwo-electrode voltage-clamp experimentsCation selectivityProtein chimerasXenopus laevis oocytesVanadate sensitivityWild-type NaGastric HK-ATPasesXenopus oocytesLaevis oocytesATPase activityAbsence of sodiumResiduesTM4K counterpartsControl constructsOocytesConformational equilibriumAssaysImportant role