This project is comprised of research into the structure and functioning of ion transport systems. There are currently 4 active subprojects: 1) Studies of the transient-state kinetics of phosphorylation and dephosphorylation of the Na,K-ATPase catalytic site, utilizing rapid quenching techniques. 2) A study of the regulation and expression of isoforms of the Na,K-ATPase utilizing site-directed antibodies raised against synthetic peptides as identifying probes. 3) A study of the relation of the glycosylation state of the beta-subunit of the Na,K-ATPase to the expression and function of the sodium pump. 4) A study of the interactions between the catalytic and the ionophoric domains of the sodium pump utilizing steady-state kinetic and radiometric binding techniques.