Functional properties of Na,K-ATPase, and their structural implications, as detected with biophysical techniques

A full understanding of the molecular mechanism of ion transport and energe tics of the Na,K-ATPase will require both structural and functional data. D uring recent years biophysical methods have provided a number of important pieces of information on ion binding and release and the charge transfer pr ocess. This allows the formulation of kinetic models of the transport proce ss. Although a breakthrough has not been obtained due to the lack of detail ed knowledge on the three-dimensional structure with a resolution high enou gh to identify the ion-binding sites and the transport pathway, the functio nal information has structural implications that create constraints on poss ible mechanisms of active transport. Here we describe briefly contributions of some biophysical methods to our conceptual understanding of the ion tra nsport process.