Do H+ ions obscure electrogenic Na+ and K+ binding in the E1 state of the Na,K‐ATPase?

FEBS Letters

Apell, Hans-Jürgen¹  Diller, Anna¹ 

[1] University of Konstanz, Biology, Universitätsstrasse 10, Konstanz 78457 Germany

关键词: Active ion transport;    Sodium pump;    Binding sites;    Electrogenicity;    Competition;   

DOI  :  10.1016/S0014-5793(02)03675-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In contrast to other P-type ATPases, the Na,K-ATPase binding and release of ions on the cytoplasmic side, to the state called E₁, is not electrogenic with the exception of the third Na⁺. Since the high-resolution structure of the closely related SR Ca-ATPase in state E₁ revealed the ion-binding sites deep inside the transmembrane part of the protein, the missing electrogenicity in state E₁ can be explained by an obscuring counter-movement of H⁺ ions. Evidence for such a mechanism is presented by analysis of pH effects on Na⁺ and K⁺ binding and by electrogenic H⁺ movements in the E₁ conformation of the Na,K-ATPase.

【 授权许可】

Unknown