Detailed structural analysis of exposed domains of membrane‐bound Na+, K+‐ATPase A model of transmembrane arrangement

Abstract
Exposed regions of the α‐ and β‐subunits of membrane‐bound Na+,K+‐ATPase were in turn hydrolyzed with trypsin. Resistance of the β‐subunit to proteolysis was shown to be due mainly to the presence of disulfide bridge(s) in the molecule. A model for the spatial organisation of the enzyme in the membrane was proposed on the basis of detailed structural analysis of extramembrane regions of both subunits.