This project is comprised of research into the structure and functioning of ion transport systems. Major current studies are 1) research into the basis of the kinetic heterogeneity exhibited by the Na,K-ATPase as manifest in several different rapid-quenching experiments, 2) research into the basis of the structural heterogeneity manifest in the electrophoretic mobility of the catalytic subunit of the Na,K-ATPase from Electrophorus electric organ, and 3) development and characterization of antibodies to synthetic peptides corresponding to selected portions of transport ATPase primary structure.