Studies on the Na+-K+ ATPase of skeletal muscle and nerve.

We have used monoclonal antibodies directed against skeletal muscle and neuronal plasma membranes to define surface antigens and have identified one of these antigens as the Na+-K+ ATPase. The monoclonal antibody to the Na+-K+ ATPase has facilitated an exploration of the biosynthesis and assembly of the Na+-K+ ATPase, the distribution of molecules on nerve and muscle, the regulation of expression of Na+-K+ ATPase, and the relation of the Na+-K+ ATPase to the intramembrane particles seen in freeze-fracture replicas. We have obtained new information on the glycosylation sites on the beta-subunit and evidence for antigenically different forms of Na+-K+ ATPase related to differences in proteinaceous aspects of the molecule. Finally, we are attempting to move from the protein level to the nucleic acid level of analysis by using antiserum prepared against the Na+-K+ ATPase to search for encoding cDNAs in an expression library.