Na+/K+-dependent adenosinetriphosphatase activity in mammalian kidney.

Microsomal preparations with Na+/K+-dependent ATPase activity from the outer medulla of rabbit and pig kidney were obtained. Purifications were assaied by centrifugation on sucrose discontinuous gradients and gel-filtration on Sepharose 6B, after detergent incubation. Sodium dodecylsulfate, with ATP as protecting agent, can remove a maximal amount of non specific proteins from the membranes and allows the recovery of a fraction with very high specific activity. The approach to purification by affinity chromatography techniques leads to interesting results, which induce us to pursue the present researchs to applicate an affinity method to Na+/K+-ATPase.