We have reviewed the structural and functional role of the -subunit in a subfamily of the P-ATPases known as the / -heterodimeric, cation-exchange ATPases. The subfamily consists of the various isoforms of Na+/K+ATPase and H+/K+-ATPase, both of which pump a cation out of the cell (Na+ or H+, respectively) in recycle exchange for K+. Much of the earlier work has emphasized the functional activit...

We studied the interactions of Na+, Li+, and amiloride on the Na+/H+ antiporter in brush-border membrane vesicles from rabbit renal cortex. Cation-mediated collapse of an outwardly directed proton gradient (pHin = 6.0; pHout = 7.5) was monitored with the fluorescent amine, acridine orange. Proton efflux resulting from external addition of Na+ or Li+ exhibited simple saturation kinetics with Hil...

In the Asemi-gawa area of intermediate high-pressure and low-temperature Sanbagawa metamorphic belt in central Shikoku, Japan, piemontite-quartz schists are common in which cation exchange between piemontite and garnet has been studied. Piemontite in contact with garnet usually contains two zones in which core is enriched in Mn3+ and surrounded by a rim rich in Fe3+. Garnet is Ca-Fe-bearing spe...

The theoretical development for one-dimensional, coupled migration of solutes with different ionic mobilities through clay soils that behave as ion-restrictive membranes, referred to as clay membrane barriers (CMBs), is presented. The transport formulation is based on principles of irreversible thermodynamics and accounts explicitly for coupling effects of hyperfiltration (ultrafiltration) and ...