Interaction of N-terminal peptide analogues of the Na ,K -ATPase with membranes

Abstract

The Na+,K+-ATPase, which is present in the plasma membrane of all animal cells, plays a crucial role in maintaining the Na+ and K+ electrochemical potential gradients across the membrane. Recent studies have suggested that the N-terminus of the protein's catalytic α-subunit is involved in an electrostatic interaction with the surrounding membrane, which controls the protein's conformational equilibrium. However, because the N-terminus could not yet be resolved in any X-ray crystal structures, little information about this interaction is so far available. In measurements utilising poly-L-lysine as a model of the protein's lysine-rich N-terminus and using lipid vesicles of defined composition,..