Finding Na,K-ATPase II - From fluxes to ion movements

Keywords: Ion transport, enzyme activity, flux modes, structure-function relation, electrogenicity, gated-channel concept, pump-related diseases

Abstract

After identification of the Na,K-ATPase as active ion transporter that maintains the Na+ and K+ concentration gradient across the membrane of virtually all animal cells, a long history of mechanistic studies began in which enzyme activity and ion-transport were intensively investigated. A basis for detailed understanding was laid in the so-called Post-Albers pump cycle. Developing new experimental techniques allowed the determination of different flux modes, the analysis of the kinetics of enzyme phosphorylation and dephosphorylation as well as of the transport of Na+ and K+ ions across the membrane. The accumulation of results from transport studies allowed the proposal of the gated channel concept that turned out to be a successful approach to explain the transport-related experimental findings. Eventually, it found its counterpart in the high-resolution structure of the ion pump. Recently it turned out that simple mutations of the Na,K-ATPase are the cause of several diseases.

Author Biography

Hans-Jürgen Apell, Dept. of Biology, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany

Hans-Jürgen Apell studied Physics at the University of Marburg, Germany, and graduated in Nuclear Physics. He received his PhD in Biophysics at the University of Konstanz and devoted his scientific work since then to the study of ion-transport processes in biological membranes. In 1983 he began to investigate the transport mechanism of the Na,K-ATPase with optical and electrophysiological methods. In the following years he broadened his interests also by investigations of other P-type ATPases, such as the H-ATPase from Enterococcus hirae, the SR Ca-ATPase, the gastric H,K-ATPase and the KdpFABC complex from E.coli. He is now active as Professor emeritus at the University of Konstanz.

Published
2019-03-31
How to Cite
Apell, H.-J. (2019). Finding Na,K-ATPase II - From fluxes to ion movements. Substantia, 3(1). https://doi.org/10.13128/Substantia-207
Section
Research Articles

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